G109 0648B008R01068070010 0029 DIV Moderately plagioclase olivine phyric basalt                                    Intergranular, glomeroporphyritic                                                                   Unit 29, Pillow or flow interior;(cont.)Fine grained                                                                     Olivine             Plagioclase                                                                     < 1  3                   < 1  3                   0.2-0.8    0.8-2.0                                                                                       C = An 8 , R = An 77                                                                                                                                                                                    Anhedral-euhedral                                 Euhedral                                                                                                                                                                                                                                                                                                                                                                                                                                                          Some hopper and swallowtail. Margins embayed and/or fractured. Yellow alteration material lines cracks in plag.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Plagioclase         Clinopyroxene       Opaques             Mesostasis                              42   45   8    < 1       42   45   8    1         0.1        ?          0.03       ?                     An 65                                                                                                                                                                                                                                                     Subhedral-euhedral                                ?                                                 Skeletal-euhedral                                 ?                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Commonly altered.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Clays                                                                                                                                                           < 1                                     Mesostasis                                                                                                                                                                                                                                                                                                                      Mesostasis altered to olive green clay with perceptible birefringence. Affects 75% of mesostsis within halo area. Bright red and transitional brown-orange types of alteration (Fe hydroxides) also present.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    WHERE SAMPLED CONTINUED: intersects alteration halo.  MAIN COMMENTS: Plag compositions determined using A-normal method.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                N
G109 0648B009R01017022003 0030 DIV Sparsely plagioclase olivine phyric basalt                                      Variolitic with some intersertal and intergranular                                                  Unit 30, pillow or flow interior        Fine                                                                             Olivine             Plagioclase         Spinel                                                      < 1  1    Tr             < 1  1    Tr             0.15-0.30  0.10-1.50  0.06                                                                                                                                                                                                                                                                                       Subhedral-euhedral                                Euhedral                                          Euhedral                                                                                                                                              Rare trapped melt inclusions.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Included in plag phenocrysts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Plagioclase         Clinopyroxene       Opaques             Mesostasis                              46   42   5    5         46   42   5    5         < 0.01-0.05< 0.01-0.05</= 0.01   ?                                                                                                                                                                                                                                                                               ?                                                 Acicular, dendritic                               ?                                                 ?                                                                                                   Elongate with hopper and swallowtail terminations                                                                                                                                                                                                         Variolitic. Acicular., Intergrown with plag.                                                                                                                                                                                                              Ulvospinel, ilmenite, sulfide.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Vesicles                   < 1            0.1-0.2                          With glomerocrysts                                          None                                                                                                                    Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Mesostasis consists of mixture of acicular plag, plumose cpx, glass and opaques.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        N
G109 0648B009R01069071010 0031 DIV Plagioclase olivine phyric basalt                                               Variolitic/glomeroporphyritic, plumose-microlitic                                                   Unit 31, cut at shallow angle to halo.  Fine-medium                                                                      Olivine             Plagioclase                                                                     < 1  2                   < 1  2                   0.15-0.50  0.50-3.00                                                                                     An > 65                                                                                                                                                                                                 Subhedral                                         Subhedral-euhedral                                                                                                                                                                                      Occurs only in glomerocrysts. Fresh.                                                                                                                                                                                                                      Mostly as glomerocrysts. Fresh except as below. One large plag glomerocryst 4 mm across, with a small aggregate of olivines. Plag glomerocrysts otherwise olivine-free.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Plagioclase         Clinopyroxene       Plumose cpx         Mesostasis          Ilmenite (?)        35   19   39   1    1    35   19   39   2    1    0.5-3.0    ?          < 1 micron ?          5 microns                                                                                                                                                                                                                                                            Euhedral                                          Anhedral                                          Subhedral                                         Anhedral                                          Subhedral                                         Acicular to lath-shaped. Hollow and hopper types.                                                                                                                                                                                                         Intergranular.                                                                                                                                                                                                                                            Plumose aggregates of microlites.                                                                                                                                                                                                                         Clear, near colorless.                                                                                                                                                                                                                                    Mainly occurs within plumose cpx, perpendicular to cpx.                                                                                                                                                                                                    Vesicles vesicles vesicles 7              0.1-2.0                                                                                      Clay linings                                                                                                            Round                                                                                                                   Vesicles were usually impregnated with resign before sectioni g. Three types of vesicle linings: 1) Olive-geen/brown clay lining. Non-birefringent. Occurs in two vesicles at/near edge of the slide near a large glomerocryst. Browner band overgrown by  pale green band. Thickness ).05 mm.  2) Simple yellow clay shows parallel and radiating growth structures. Thickness 0.01-0.08 mm, variable between vesicles. Some small vesicles are filled.  3) Celadonite/iron hydroxide linings. Shown by one large  vesicle and one small one adjacent to a large glomerocryst. Sequence is (a) discontinous thin lining of dark red to opaque "iron hydroxide" with some bulbous protrusions; (b) normal parallel to radiating yellow celadonite;(Continued in main comments) Clays               Clays               Clays               Clays               Clays                                                                           < 2                                     Mesostasis, plumose cpx                                                                                                                                                                                                                                                                                                         Leading edge of dark halo shows alteration of mesostasis to olive-green clay (probably corresponds to thin dark line seen on dry sawn surfaces). Clay is non-birefringent, 2 mm from edge of halo, clay changes gradationally from olive-green through    yellow-green to orange-yellow, birefringent clay over a distance of about 2 mm. (N.B., distances not perpendicular to halo boundary.) 3 mm further in, patches of monomineralic clay 0-2 mm across, replaces both mesostasis and plumose cpx.             This sequence holds good for the half of the slide opposite the large plag glomerocryst. In the other half, alteration is generally of the  live-green clay type, interupted by a crack, along which intense orange-yellow clay + darker brown to opaque  Fe hydroxide alteration replaces mesostasis, cpx, and in the center of the zone, plag and parts of ol. This alteration passes out via yellow clay into olive-green clay replacing mesostasis only. Yellow clay infills fractures in the large plag        glomerocryst.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           GROUNDMASS CONTINUED: Spinel/magnetite, % present = 1, % original = 1, size = 5 microns, morphology = euhedral, comment; mainly in non-plumose textured areas.  VESICLE COMMENTS CONTINUED: (c) discontinuous layer of translucent isotropic " iron hydroxide". The colors of the clay components of the vesicle linings are the same as the clay replacing the adjacent groundmass mesostasis. Vesicle clays of types (1) and (2) occur within 1 mm of each other.  MAIN COMMENTS:  Section is half altered, half fresh. Modal % estimated for fresh part.                                                                                                                                                                                                                                                                                                                                                                                                                                                                             N
G109 0648B009R01080082011 0031 DIV Sparsely olivine plagioclase phyric basalt                                      Intersertal to intergranular, variolitic                                                            Unit 31, Pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     < 1  < 1                 < 1  < 1                 0.05-0.10  0.40-1.40                                                                                                                                                                                                                                                                                             Subhedral                                         Subhedral                                                                                                                                                                                               Fresh.                                                                                                                                                                                                                                                    Fresh.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Plagioclase         Clinopyroxene       Opaques             Mesostasis                              40   47   8    4         40   47   8    4         0.1-0.3    ?          0.01-0.11  ?                                                                                                                                                                                                                                                                               Elongate,hopper                                   ?                                                 Anhedral-euhedral                                 ?                                                                                                   Also swallowtail forms.                                                                                                                                                                                                                                   Intergranular                                                                                                                                                                                                                                             Some skeletal crystals.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Vesicles                   4              0.5-2.5                          Even                                                        None                                                                                                                    Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  N
G109 0648B013R01000003001 0032 DIV Moderately plagioclase olivine phyric basalt                                    Variolitic                                                                                          Unit 32, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     1    3                   1    3                   0.1-0.5    0.5-1.4                                                                                                                                                                                                                                                                                               Anhedral-euhedral                                 Rounded, euhedral                                                                                                                                                                                       Some melt inclusions.                                                                                                                                                                                                                                     Margins commonly fractured and/or embayed. Complex zoning patterns. Common intergrowths of two or more plag phenocrysts. Ol and plag phenocrysts form glomerocrysts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     Plagioclase         Mesostsasis                                                                     20   76                  20   76                  0.01-0.2   ?                                                                                                                                                                                                                                                                                                     Acicular to tabular                               ?                                                                                                                                                                                                       Hopper and swallowtail forms also present.                                                                                                                                                                                                                Microcrystalline intergrowth of acicular plag microlites, dendritic cpx, small pools of reddish glass, and small granular opaque minerals. Opaques include ulvospinel, and ilmenite. Plumose pattern developed in mesostasis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   < 1%           0.2-0.5                          Even                                                        Some glass                                                                                                              Round                                                                                                                                                  May be partially to completely glass-filled. Mesostasis and plag microphenocrysts wrap around vesicles.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Groundmass plag described above are microphenocrysts. These are significantly larger than the plag microlites in the mesostasis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        N
G109 0648B013R01011013002 0032 DIV Moderately olivine plagioclase phyric basalt                                    Intergranular, variolitic                                                                           Unit 32, pillow or flow interior        Fine to medium                                                                   Olivine             Plagioclase                                                                     2    2                   2    2                   0.2-0.6    0.4-1.2                                                                                                                                                                                                                                                                                               Anhedral-subhedral                                Subhedral-euhedral                                                                                                                                                                                      Also skeletal and fresh crystals.                                                                                                                                                                                                                         Some very irregular crystals with embayed and/or fractured margins.Zoning common. Occasional hopper crystals. Occasional intergrowths of two or more phenocrysts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Plagioclase         Clinopyroxene       Olivine             Opaques             Mesostasis          40   46   Tr   10   Tr   40   46   Tr   10   Tr   0.04-0.25  ?          ?          ?          ?                                                                                                                                                                                                                                                                    Subhedral-euhedral                                ?                                                 Elongate                                          ?                                                 Cryptocrystalline                                 Common swallowtail. Some hopper.                                                                                                                                                                                                                          Intergranular. Microcrystalline.                                                                                                                                                                                                                          Sinuos grains associated with plag glomerocrysts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Vesicles                   Tr             0.04-0.20                        Even                                                        None                                                                                                                    Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  N
G109 0648B015R01033037015 0034 DIV Sparsely plagioclase olivine phyric basalt                                      Variolitic, glomeroporphyritic                                                                      Unit 34, pillow or flow interior        Microcrystalline                                                                 Olivine             Plagioclase                                                                     < 1  1                   < 1  1                   0.4-0.5    0.5-1.5                                                                                                                                                                                                                                                                                               subhedral-euhedral                                Euhedral-subhedral                                                                                                                                                                                                                                                                                                                                                                                                                                                Some crystals are skeletal including cryptocrystalline materials.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Plagioclase         Clinopyroxene(+glassOpaques                                                     45   45   8              45   45   8              0.01-0.03  </=2 micron1-3 microns                                                                                                                          Titanomagnetite, ilmenite                                                                                                                             Elongated                                         ?                                                 Euhedral-subhedral                                                                                                                                    Some crystals are skeletal.                                                                                                                                                                                                                               Cryptocrystalline to microcrystalline. Forms variolitic texture with groundmass plag and opaques.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Vesicles                   < 1            0.5-1.2                          Even                                                        None                                                                                                                    Round                                                                                                                   Partially coated by cryptocrystalline materials (originally glass).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            N
G109 0648B015R01111113015 0035 DIV Moderately plagioclase olivine phyric basalt                                    Intergranular, variolitic                                                                           Unit 35, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     1    3                   1    3                   ~ 0.5      1-2.5                                                                                                                                                                                                                                                                                                 Round                                             Euhedral                                                                                                                                                                                                Intergrown with plag glomerocrysts.                                                                                                                                                                                                                       Some glass inclusions (5 micron round blebs), crystallographically orientated parallel to plag crystal faces.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Plagioclase         Pyroxene            Opaques             Mesostasis                              46   44   5    1         46   44   5    1         ?          ?          ?          ?                                                                                                                         Spinel, ilmenite, Fe sulfide                                                                                                                          Euhedral                                          Euhedral                                          ?                                                 ?                                                                                                   Some hopper shaped crystals, intergrown with cpx.                                                                                                                                                                                                         Internally skeletal to dendritic. Some radiate textures.                                                                                                                                                                                                  Spinel, ilmenite, Fe sulfides. Spinel is euhedral to internally skeletal. Ilmenite is elongated. Fe sulfides occur as spheres.                                                                                                                            Rare patches.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Vesicles                   5                                               Even                                                        None                                                                                                                    Round                                                                                                                   Contain dark fine-grained partial linings. May be a filling by late stage residual liquid. In all vesicles, the partial lining is on the same side.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            N
G109 0648B015R01120123016 0035 DIV Sparse olivine plagioclase phyric basalt                                        Intergranular, variolitic                                                                           Unit 35, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     < 1  < 1                 < 1  < 1                 0.2-0.3    0.8-1.0                                                                                                                                                                                                                                                                                               Euhedral-subhedral                                Euhedral                                                                                                                                                                                                Some glass inclusions.                                                                                                                                                                                                                                    fractured margins. Concentric zoning.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Plagioclase         Clinopyroxene       Olivine             Opaques                                 45   48   1    5         45   48   1    5         0.05-0.50  ?          0.04-0.08  0.01-0.07                                                                                                                                                                   Ulvospinel, ilmenite                                                                                Subhedral-euhedral                                Acicular, dendritic                               Anhedral                                          ?                                                                                                   Also acicular, hopper, and swallowtail crystal forms.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Ulvospinel crystals are anhedral to euhedral. Ilmenite crystals are bladed.                                                                                                                                                                                                                                                                                                                                                                                                                                          Vesicles                   5              0.8-3.2                          Even                                                        None                                                                                                                    Round                                                                                                                   Spinel (?) crystallized on the edge of one vesicle.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            N
G109 0648B016R01002005001 0035 DIV Moderately plagioclase olivine phyric basalt                                    Glomeroporphyritic, intersertal and intergranular                                                   Unit 35, cut perpendicular to alterationFine-medium                                                                      Olivine             Plagioclase                                                                     1.5  2                   1.5  2                   0.1-0.6    0.6-3.0                                                                                       C = An>65                                                                                                                                                                                               Subhedral                                         Subhedral                                                                                                                                                                                               Occur in ol-plag glomerocrysts.                                                                                                                                                                                                                           Resorption indicated by deep embayment of largest phenocryst, which also has numerous crystallographically orientated trapped melt inclusions. Most Phenocrysts have ragged edges which are overgrown by opitically continuous hollow plag (continued)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Plagioclase         Clinopyroxene       Titanomagnetite     Mesostasis                              33   37   1    24        33   37   1    25.5      0.1-1.0    < 0.1      < 0.05     ?                                                                                                                                                                                                                                                                               Euhedral                                          ?                                                 Euhedral-subhedral                                ?                                                                                                   Mainly hollow lath-shaped to acicular.                                                                                                                                                                                                                    Occurs as equant or prismatic grains in mesostasis, as radiating plumose aggregates (some intergrown with plag), or intergranular to plag.                                                                                                                                                                                                                                                                                                                                                                          Intersertal. Dark to opaque, with acicular opaques.                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Vesicles Vesicles          10             0.3-3.0                                                                                      +/- Clay                                                                                                                Round                                                                                                                   Vesicles generally empty. The two that are connected by the shorter fracture mentioned above are lined with Fe hydroxide, +/- thin clay. Some plucking of vesicle linings from the section may have occured. Three vesicles have a near-glass lining on   one side.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Clays                                                                                                                                                           1.5                                     Mesostasis                              Fracture filling                                                                                                                                                                                                                                                                        Within the halo area, intersertal mesostasis is partially to completely by yellow clay or orange-red Fe hydroxide. This alteration is confined to a fe                                                                                                    Two 0.1 mm fractures run through the halo area, subparallel to the halo boundary. there is a very incomplete filling of red Fe hydroxide in the longer                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                PLAGIOCLASE PHENOCRYST COMMENTS CONTINUED: (resmbling groundmass plag).  MAIN COMMENTS: Vesicle and phenocryst abundances visually estimated.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           N
G109 0648B016R01048050005 0036 DIV Moderately plagioclase olivine phyric basalt                                    Intergranular                                                                                       Unit 36, pillow or flow interior        Fine-medium                                                                      Olivine             Plagioclase                                                                     2    3                   2    3                   0.05-0.07  0.50-1.20                                                                                                                                                                                                                                                                                             Euhedral-anhedral                                 Euhedral-subhedral                                                                                                                                                                                      Forms glomerocrysts with plag. Various skeletal shapes.                                                                                                                                                                                                   Albite and carlsbad twinning. Well developed zoning at the outer margins of the grains.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Olivine             Plagioclase         Clinopyroxene       Titanomagnetite                         1    55   31   8         1    55   31   8         0.01-0.05  0.01-0.3   0.05-0.3   0.01-0.03                                                                                                                                                                                                                                                                       Euhedral-anhedral                                 Acicular, laths                                   Plumose                                           Anhedral-acicular                                                                                   Blade-like intergrowth with plag or isolated.                                                                                                                                                                                                             Microlites with some hollow cores.                                                                                                                                                                                                                        Prismatic in intergranular spaces.                                                                                                                                                                                                                        May be found as inclusions in plag crystals.                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Vesicles                   0.6            < 1                                                                                          None                                                                                                                    Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Point count: 1000 points, 0.5 mm grid. Some glomerocryst show a radial pattern. Generally, plag is the dominant phase in glomerocrysts, forming sub-ophitic-like intergrowths with or wrapping around ol grains.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        N
G109 0648B016R01088090009 0036 DIV Highly olivine plagioclase phyric basalt                                        Intergranular, glomeroporphyritic                                                                   Unit 36, pillow or flow interior        Fine-medium                                                                      Olivine             Plagioclase                                                                     5    5                   5    5                   0.1-0.8    0.4-1.4                                     Fo 79                                                                                                                                                                                                                                                     Anhedral-subhedral                                Euhedral                                                                                                                                                                                                Occurs mostly in plag-olivine glomerocrysts. Melt inclusions.                                                                                                                                                                                             Common embayed and fractured margins. Complex zoning patterns. Common intergrowth between two or more plag crystals. Melt inclusions.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Plagioclase         Clinopyroxene       Opaques             Olivine                                 35   46   8    1         35   46   8    1         0.01-0.20  ?          0.04-0.08  ?                                                                                                                         Ilmenite,magnetite                                                                                                                                    Subhedral-euhedral                                Acicular, dendritic                               Anhedral-euhedral                                 Anhedral-subhedral                                                                                  Hopper and swallowtail forms also present.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Vesicles                   < 1            0.2-0.6                          Even                                                        None                                                                                                                    Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Plag has seriate grain size distribution. Range of grain sizes quoted above for "groundmass" plag includes both small, acicular plag in Ol composition determined by XRD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               N
G109 0648B017R01022024005 0038 DIV Moderately plagioclase olivine phyric basalt                                    Intergranular, glomeroporphyritic                                                                   Unit 38, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     2    4                   2    4                   0.1-0.4    0.2-1.0                                     Fo 80                                             C = An 60 R = An 75                                                                                                                                                                                     Subhedral-anhedral                                Euhedral                                                                                                                                                                                                In glomerocrysts with plag.                                                                                                                                                                                                                               Core and rim compositions were taken on two separate crystals. Complex zoning. Fractured margins. Discrete crystals and glomerocrysts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Plagioclase         Clinopyroxene       Olivine             Opaques                                 42   46   1    5         42   46   1    5         0.02-0.15  ?          0.05       0.01-0.02                                                                                                                                                                   Titanomagnetite,ilmenite,sulfides                                                                   Subhedral-euhedral                                Dendritic, bladed                                 Anhedral                                          Anhedral-euhedral                                                                                   Also acicular, swallowtail, and hopper forms present.                                                                                                                                                                                                     Cpx is intergranular to plag laths.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Titanomagnetite is euhedral, skeletal. Ilmenite is bladed, lath-like. Sulfides are bleb-like.                                                                                                                                                                                                                                                                                                                                                                                                                        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G109 0648B018R01000002001A0040 DIV Sparsely plagioclase olivine phyric basalt                                      Seriate, sub-ophitic                                                                                Unit 40, alteration halo                Medium                                                                           Olivine             Plagioclase         Plag continued      Plag continued                          0.5  1                   0.5  1                   0.5-1.0    1.0-3.0                                                                                                                                                                                                                                                                                               Equant, anhedral                                  Subhedral                                                                                                                                                                                               In poorly defined glomerocrysts.                                                                                                                                                                                                                          Six crystals are large enough to be called phenocrysts. Various crystals have different features, listed below. 1) Inclusion-free, almost unzoned core. Normally zoned rim with intricate intergrowth with groundmass sized cpx, ol, and mesostasis.      2) Similar to (1), but lacking distinct zonation. 3) Composite crystal: rounded, almost unzoned plag and small anhedral olivine enclosed in unzoned core. Ol inclusion acts as a nucleus for one of several aggregates of quenched-looking ol(?) growths. 4) Elongate, weakly zoned, with abundant cpx, magnetite, and mesostasis inclusions oriented parallel to length. 5) Elongate, zoned glomerocrysts with few inclusions. (two examples.)                                                                                                                                                                                                                                                                                                                                Olivine             Plagioclase         Clinopyroxene       Titanomagnetite     Mesostasis          5    47.5 26   12   8    5    54   30   12   8    0.2-1.5    0.1-2.0    0.1-2.0    0.02-0.10  ?                                                                                                                                                                                                                                                                    Anhedral                                          Subhedral                                         Anhedral                                          Euhedral, skeletal                                ?                                                 Equant to sub-poikilitic, elongated parallel to C axis.                                                                                                                                                                                                                                                                                                                                                                                                                                                             Equant intergrowths or sub-poikilitic.                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Intersertal, partially crystallized.                                                                                                                                                                                                                       Vesicles                   < 0.5          < 0.2                                                                                        Clay linings                                                                                                            Round                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Alteration minerals, from edge of halo inward toward site of fracture: 1) Small amounts of olive-green, low-birefringent clay. Partially replaces mesostasis, with an associated more general brown discoloration of the mesostasis.                      2) A variety of yellow to orange birefringent clays. Commonly forms fringes on scarce vesicles, replacing mesostasis. Also fills microfractures. Associated red-orange, non-birefringent "Fe hydroxide" +/- birefringent clay forms globular masses up to 0.2 mm (gives gray reflective polished surface) and irregulart replacements of mesostasis.                                                                                                                                                                3) A zone at least 2-3 mm wide along the edge of the section nearest the fracture has relatively little distinctive alteration material (very sparse, mainly Fe hydroxide). Reflected light shows that the mesostasis is in fact pervasively altered to a soft (hydrated) material.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Interesting groundmass textures: 1) Elongate ol in optical continuity extended for up to 3 mm parallel to the c-axis, forming sub-poikilitic relationship to plag. Locally overgrown by intergranular cpx in near optical continuity with ol. Similar elongated ol extends in continuity from the 1 mm equant ol phenocryst, with rods of the same crystal extending 0.1 mm into enclosing cpx and plag (cpx is not in optical relation to ol). Some ol ,oikocrysts partially enclose and interpenetrate a plag lath orientated parallel to the c-axis of ol. More equant, sub-poikilitic to intergranular ol is common in the vicinity of the 1-mm sized ol phenocryst. 2) "bow-tie" structures: rare occurance defined by intersecting plag laths and by a gap in plag enclosed in ol oikocryst. 3) Rare hollow subhedral olivine crystals enclosing plag and mesostasis.                                                                                                                                                             N
G109 0648B018R01038040002 0040 DIV Sparsely plagioclase olivine phyric basalt                                      Intergranular, intersertal, hypocrystalline                                                         Unit 40, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     < 1  1                   < 1  1                   0.1-0.6    0.8-1.0                                                                                                                                                                                                                                                                                               Anhedral-subhedral                                Euhedral-subhedral                                                                                                                                                                                                                                                                                                                                                                                                                                                Complex zoning. Embayed margins.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Plagioclase         Clinopyroxene       Olivine             Glass               Opaques             43   40   5    3    7    43   40   5    3    7    0.01-0.04  0.02-0.20  0.03-0.08  ?          0.02-0.20                                                                                                                                                                                                          Magnetit,ilmenit,sulfides                         Subhedral-euhedral                                Anhedral                                          Anhedral                                          ?                                                 ?                                                 Tabular                                                                                                                                                                                                                                                   Most anhedral. Intergranular. Some bladed, dendritic.                                                                                                                                                                                                                                                                                                                                                                                                                                                               Brown patches 0.03-0.05 mm. Fills interstice between plag laths.                                                                                                                                                                                          Magnetite, subhedral. Ilmenite, bladed. Sulfide, blebs.                                                                                                                                                                                                    Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  GROUNDMASS CONTINUED: Spinel % present = << 1, % original = << 1, size = 0.05 mm, morphology = euhedral.  MAIN COMMENTS: Needles of plag and cpx are enclosed in pools of glass.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        N
G109 0648B019R01013015026 0040 DIV Sparsely plagioclase olivine phyric basalt                                      Intergranular                                                                                       Unit 40, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     < 1  1                   < 1  1                   < 0.5      2.0-4.0                                                                                                                                                                                                                                                                                               Rounded, skeletal                                 ?                                                                                                                                                                                                                                                                                                                                                                                                                                                                 ~ 1 mm wide perpendicular to (010).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Plagioclase         Clinopyroxene       Mesostasis          Opaques             Olivine             44   50   1    3    < 1  44   50   1    3    < 1  0.02-0.10  0.02-0.10  ?          ?          0.10                                                                                                                                                                                                                                                                 Tabular-euhedral                                  Acicular                                          ?                                                 ?                                                 Equant                                            Also subhedral morphology. Grains measured perpendicular to (010).                                                                                                                                                                                        Measurments represent needle widths.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Point count: 1000 points, 0.5 mm grid.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  N
G109 0648B020R01048050006 0041 DIV Sparsely plagioclase olivine phyric basalt                                      Trachytic, pilotaxitic                                                                              Unit 41, pillow or flow interior        Fine                                                                             Olivine             Plagioclase                                                                     < 1  1                   < 1  1                   0.1-0.3    0.2-1.0                                                                                                                                                                                                                                                                                               Subhedral-anhedral                                Euhedral                                                                                                                                                                                                In glomerocrysts with plag.                                                                                                                                                                                                                               Some skeletal with embayed margins and cracks. Some plag has oscillatory or sweeping extinction.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Plagioclase         Clinopyroxene       Olivine             Mesostasis                              45   20   1    33        45   20   1    33        0.01-0.07  < 4 microns0.01-0.04  ?                                                                                                                                                                                                                                                                               Elongate, acicular                                Acicular, dendritic                               Anhedral-euhedral                                 ?                                                                                                   Lenfth:width = 1:10 to 1:40. Subparallel alignment.                                                                                                                                                                                                       Comb-like needles.                                                                                                                                                                                                                                        Some hollow, swallowtail.                                                                                                                                                                                                                                 Consists of microcrystalline to cryptocrystalline mixture of plag, cpx, opaques and minor glass.                                                                                                                                                                                                                                                                                                                                                                                                                     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