G109 0669A001D01007009001 0001 DIV Aphyric basalt                                                                  Variolitic to microlitic                                                                            Unit 1, pillow or flow interior,(cont.) Fine                                                                             Olivine                                                                                             Tr                       Tr                       0.3-0.6                                                                                                                                                                                                                                                                                                          Subhedral                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Plagioclase         Olivine             Clinopyroxene       Mesostasis          Opaques             29   3    11   54   0.5  29   3    11   54   0.5  51         0.05-0.2   < 0.1      ?          3-10 mirons                                                                                                                                                                                                         Magnetite                                        Acicular, bunches                                 Euhedral, skeletal                                Radiating, plumose                                ?                                                 Anhedral-euhedral                                 Radiating. Associated with rare ol nucleus of plag. L/W = 10-30.                                                                                                                                                                                          Generally attached to plag.                                                                                                                                                                                                                               Rare small grain associated with radiating plag. Product of glass devitrification. Rare euhedral crystals.                                                                                                                                                Dark brown, isotropic with plag and cpx crystallites.                                                                                                                                                                                                     Tiny grains distributed in the mesostasis.                                                                                                                                                                                                                 Vesicles                   1.5            0.2-0.8                          Even                                                                                                                                                                                Rounded to irregular                                                                                                    Miaroles in alteration halos are more commonly filled with clays than the vesicles. Empty in fresh mesostasis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Clays               Carbonate           Fe hydroxide                                                                                                            2    Tr   0.5                           Mesostasis                              Miaroles                                Mesostasis                                                                                                                                                                                                                                      Yellow birefringent clay.                                                                                                                                                                                                                                 Aragonite, radiating. SEM photo tacken before sectioning.                                                                                                                                                                                                 Both red and opaque varieties.                                                                                                                                                                                                                            HALO ZONE 34 mm wide                                                                                                                                                                                                                                      Yellow clay: Strongly colored. Almost cryptocrystalline. Low birefringence. Occurs mainly as homogeneous partial fillings of miaroles. These fillings are up to 3.5 mm in extent,with groundmass plag, cpx, ol, and titanomagnetite projecting into the   clay. Clay has botryoidal, locally radiate growth structure. The same clay also forms partial replacements of brown mesostasis-(?)glassy component. Replacment of mesostasis ocassionally nearly complete. Orange-red clay: Trace amounts, mainly as      miarole lining. Transitioned between yellow clay and ref Few hydroxide.  Red Fe hydroxide: Occurs mainly in fractures, lining vesicles and forming the central parts of miarole fillings. Vesicle linings up to 50m. Cracks < 10m wide locally spacedat   100m intervals. Occasionally occursas 330 - 50m grains attached to miarole walls, then overgrown by yellow clay. In one case, a bleb of Fe hydroxide attached to a miarole wall is continuous with a 31m thick Fe hydroxide veinlet.Cont. in main commentsWHERE SAMPLED CONTINUED: cut perpendicular to dark halo.  SECONDARY MINERAL COMMENTS CONTINUED:  Opaque Fe hydroxide; Occurs as central parts of two or three miarole linings. Point count of halo zone; 26 yellow clay (5%), 7 red Fe hydroxides (1.5%), 1 opaque Fe hydroxide (Tr), and 466 primary phases. Central zone (fresh); Traces of orange to red Fe hydroxide, mainly near vesicle walls. Radiating aggregates of aragonite (biaxial, low 2V, extreme birefringence) in large (5 mm), irregular miarole (also containing hopper ol). This and a smaller aragaonite-filled miarole are in connection with the halo zone. MAIN COMMENTS:  Rare ol phenocrysts are rather microphenocrysts. Mesostasis is cryptocrystalline to microcrystalline with plag,cpx and ol microlites. this section might represent a coarser equivalent of Section 669A-1D-1 (Piece 2, 11-13 cm).                                                                                                                                                    N
G109 0669A001D01011013002 0001 DIV Aphyric basalt                                                                  Intergranular (felty)                                                                               Unit 1, pillow or flow interior         Microcrystalline to fine                                                         Olivine                                                                                             0.5                      0.5                      0.2-0.4                                                                                                                                                                                                                                                                                                          Euhedral-subhedral                                                                                                                                                                                                                                        Some embayment. Some glass inclusions.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Olivine             Plagioclase         Clinopyroxene       Mesostasis          Opaques             5    26   39   21   4.5  7    26   40   21   5.5  < 0.1      < 0.1      0.1-0.3    ?          << 0.1                                                                                                                                                                                                             Magnetite, sulfides                               Euhedral,quenched                                 Acicular, hopper                                  Anhedral, plumose                                 ?                                                 Anhedral                                          Radiating, swallow tail.                                                                                                                                                                                                                                  Radiating, spherulites.                                                                                                                                                                                                                                   Christmas-tree texture, product of glass devitrification.                                                                                                                                                                                                 Dark brown with some cpx and plag crystallites.                                                                                                                                                                                                           Very minute grains in mesostasis or cpx.                                                                                                                                                                                                                   Vesicles                   2              0.2-0.4                          Even                                                        Clays, Fe hydroxide                                                                                                     Rounded or irregular                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Clays               Fe hydroxide                                                                                                                                3    1                                  Vesicles, miaroles, ol, cpx             Opaques                                                                                                                                                                                                                                                                                 Yellow. Replaces olivine and clinopyroxene (staining).                                                                                                                                                                                                    Reddish brown to red. Individual granules.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            groundmass continued: Segregation vesicle, % present = Tr, % original = Tr, size = 0.2-0.5 mm, morphology = rounded, comment = mostly devitrified glass.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                N
G109 0669A001D01011012002 0001 DIV Aphyric basalt                                                                  Spherulitic to variolitic                                                                           Unit 1, pillow or flow interior         Microcrystalline                                                                 Olivine                                                                                             Tr                       Tr                       -2.5                                                                                                                                                                                                                                                                                                             Anhedral                                                                                                                                                                                                                                                  Yellow hydroxide attached to the phenocryst.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Plagioclase         Olivine             Clinopyroxene       Mesostasis          Opaques             34   6    33   22   2    35   6    33   24   2    < 0.6      < 0.1      < 0.4      ?          microns                                                                                                                                                                                                            Magnetite                                         Bundles, hopper,                                  Euhedral,swallowtail                              Radiating, plumose                                ?                                                 Anhedral                                          Morphology continued: acicular. COMMENTS: Radiating. Associated with cpx or attached ol.                                                                                                                                                                  Attached to plag.                                                                                                                                                                                                                                         Christmas-tree shape. Forms spherulites with plag or in the mesostasis.                                                                                                                                                                                   Dark brown, isotropic. Investigation under reflected light reveals plag and cpx crystallites.                                                                                                                                                             Minute grains distributed in the mesostasis only.                                                                                                                                                                                                          Vesicles                   2              0.05-0.8                         Even                                                        Fe hydroxide                                                                                                            Irregular                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Fe hydroxide                                                                                                                                                    2                                       Vesicles, mesostasis                                                                                                                                                                                                                                                                                                            Yellow to reddish brown. Associated with plag, cpx, and ol or randomly distributed in the groundmass. The granules are attached to the crystals or interfingered with cpx.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Actual interval is from 11-13 cm, however the preceeding thin section had the same ID.  Ol phenocrysts are in fact microphenocrysts. These are, however, different from quenched ol grains. Mesostasis is cryptocrystalline with recognizable cpx and plag in a radiating pattern. Segregation vesicles consisting of minute crystals of plag + cpx + cryptocrystalline material constitute approximately 1% of the rock.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               N