G109 0670A001D01019021004 0001 KOM Serpentinized harzburgite (aphyric)                                             Porphyroclastic                                                                                     Massive Peridotite                      Medium-coarse                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Orthopyroxene       Spinel              Olivine             Clinopyroxene(?)                        1    1    0    <1        8    1    89   2         0.8-6.4    0.08-1.8   0.1-0.8    0.01-0.25             En90                                              Cr#=50                                                                                                                                                                                                  Lensoid                                           Xenomorphic                                       Olivine pseudomorphs are polygonal                Polygonal                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Possible cpx.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Carbonate           Chlorite            Magnetite           Talc                Lizardite           Chrysotile          Pargasite           Biotite             1    2    10   5    65   3    <1   10   Replacing olivine, filling veins        Replacing ol; intergrown w/magnetite    Fills veins, outlines former ol, rims mtSurround & replacespresent & former opx Replaces ol, also chrysotile                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Dispersed throughout.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Mesh texture.                                                                                                                                                                                                                                             Veins                                                                                                                                                                                                                                                     Possible pargasite replacing cpx.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Opx is bent into lensoid shape and has sweeping, undulatory extinction. Carbonate veins (0.04-0.20 mm) are long and branching. They cut serpentine and magnetite veins, and appear to be the last event in the developement of the rock. Serpentine veins occur as two types. The first type is 0.8-3.2 mm long, and 0.05-0.15 mm wide, lensoid gashes which are highly birefringent. These veins crosscut magnetite veins but not carbonate veins. The second type is 0.01-0.5 mm wide, and is lined with magnetite. These veins cross cut the entire section.                                                                                                                                                                                                                                                                                                                                                                                                                                                                         N
G109 0670A002D01045047010 0001 BDC Clinopyroxene-bearing serpentinized harzburgite                                 Porphyroclastic                                                                                     Plutonic intrusion                      Coarse-grained porphyroclasts set in fine grained matrix                         Olivine             Clinopyroxene       Spinel              Orthopyroxene                           ?    trace0.4  trace     88.5 ~1   0.5  10        0.5-1.2    2          0.2-0.7    1.5-8.0                                                                 Diopside                                          Picotite                                          Enstatite                                                                                           Hexagonal                                         Rounded                                           Irregular, hercynite, holly-leaf                  Tabular, prismatic or contorted                                                                     Olivine acquired a granoblastic texture during recrystallization. Mesh texture forms after olivine neoblasts, composed of lizardite and magnetite.                                                                                                        Porphyroclast is bent.                                                                                                                                                                                                                                    Translucent, yellow-brown. Margin altered to opaques (ferritchromite?).                                                                                                                                                                                   Porphyroclasts are kinked but some others are undeformed.                                                                                                                                                                                                                                                                                                                                                                                                                                                            ?                                                                                                   ?                        ?                        ?                                                                                                                                                                                                                                                                                                                ?                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Carbonate           Bastite             Lizardite           Chrysotile          Magnetite           Talc                Iron hydroxide      Tremolite           trace12   87.6 2    5    2    1    traceVeinlets                                Pyroxene                                Olivine                                 Veinlets                                Fractures                               Serpentine                              Magnetite                               Serpentine                              Associated with talc or by-product of cpx serpentinization.                                                                                                                                                                                               Pseudomorphs after pyroxene.                                                                                                                                                                                                                              Includes approximately 10% bastite. Mesh texture of olivine granoblasts. Opx, cpx, (lizardite) with amorphous serpentine core (or cryptocrystalline chlorite).                                                                                            White to pale yellow, transversal fibers. Veinlets crosscut all the metamorphic phases and are deformed. At least two generations.                                                                                                                        Seems to be around mesh texture olivine, or filling fractures in cpx, olivine-rich part of the thin section.                                                                                                                                              Flaky lining opx porphyroclasts, replaces serpentine (lizardite).                                                                                                                                                                                         Late alteration of magnetite or flollow chrysotile veinlets.                                                                                                                                                                                              Needles < 0.1 mm fringing opx pseudomorphs.                                                                                                                                                                                                               Sequence of events: 1) High temperature plastic deformation. 2) Low temperature serpentinization; lizardite, biotite, magnetite, and alteration of Cr spinel. 3) Talc replaces serpentinized pseudomorphs (lining of porphyroclasts). 4) Chrysotile veins crosscuts every metamorphic mineral. 5) Iron hydroxide alters magnetite and follows chrysotile veinlets in some places.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       N
G109 0670A003W01012014002 0001 RIC Serpentinized harzburgite                                                       Porphyroclastic                                                                                     Exterior end of pp/pm minicore          Coarse                                                                           Olivine             Orthopyroxene       Spinel                                                      0    0    2              70   28   2              0.2-0.5    0.5-5.0    1-3                                                                                                                                  Chromian                                                                                                                                              -                                                 Subhedral                                         Highly irregular                                                                                                                                                                                                                                                                                                                                                                                                Completely replaced by serpentine. Commonly bent.                                                                                                                                                                                                         Replaced by opaque material. Poikiolitically enclosed by opx.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  ?                                                                                                   ?                        ?                        ?                                                                                                                                                                                                                                                                                                                ?                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Lizardite           Bastite             Carbonate           Talc                Chrysotile          Magnetite                                                   68   26   1    <0.5 2    1              Replacing olivine                       Opx                                     Veins                                   Opx                                     Veins                                   Spinel                                                                                                                  Reticulate texture.                                                                                                                                                                                                                                       Optically oriented pseudomorphs.                                                                                                                                                                                                                          Locally shows radiate growth. Veins up to 0.1 mm wide.                                                                                                                                                                                                    Oriented laminae parallel to original cleavage of opx replaced by talc.                                                                                                                                                                                   Fills subparallel veins which are up to 0.4 mm wide. These veins cross-cut narrower serpentine-magnetite veinlets.                                                                                                                                        A small amount of magnetite also occurs in lizardite, irregularly disseminated very finely, in serpentine-magnetite veinlets, and as coarser (up to 0.1 mm) disseminated material in association with disseminated carbonate at the edge of the slide.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Deformation accompanying serpentinization limited - ?bending of bastites.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               N
G109 0670A003W01019020003 0001 RIC Altered glassy basalt with zeolite veins                                        Originally glassy, microlitic, partly spherulitic                                                   From cuttings                                                                                                            Olivine                                                                                             0                        3                        0.05-0.3                                                                                                                                                                                                                                                                                                         Euhedral                                                                                                                                                                                                                                                  Altered to zeolite (single and multi-grain aggregates).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Plagioclase         Clinopyroxene(?)    Glass(?)                                                    ?    -    0              2-3  4-15 -              up to 0.2  up to 0.2  -                                                                                                                                                                                                                                                                                          -                                                 -                                                 -                                                                                                                                                     Microlites and microphenocrysts (replaced by zeolites).                                                                                                                                                                                                   Microlites are replaced by chlorite/smectite(?).                                                                                                                                                                                                          Approximately 15% of the glass is devitrified to form 1-1.5 mm dark spherulites. Both glass and spherulites are altered to amphibole(?).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Vesicles                   1              1                                                                                            Laumontite(?)                                                                                                           Round                                                                                                                   Completely filled with 0.1-0.2 mm zeolite crystals.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Clays               Clays               Zeolites            Actinolite          Sulfide                                                                         4    1    30   65   trace               Cpx?                                    Fractures                               Various                                 Groundmass                              In zeolite veins                                                                                                                                                Greenish, moderately birefringent; chlorite/smectite(?).                                                                                                                                                                                                  Some clay forms 10-15 microns coating on lava fragments and fills some fractures up to 15 microns thick.                                                                                                                                                  See above for fracture fillings. Also replaces microlites and microphenocrysts.                                                                                                                                                                           Identity uncertain.                                                                                                                                                                                                                                       Chalcopyrite(?). Grains up to 20 microns.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Sequence of open space filling (any one or more may be absent): Very even 10-15 microns pale yellow-green clay (frequently absent). 2) Similarly even 10-30 microns zeolite (only locally present). 3) Fine-grained, almost isotropic zeolite with abundant inclusions. 4) Blocky, approximately 0.1-0.7 mm zeolite crystals with abundant inclusions and aggregates of type (1d) clay approximately 10-20 microns. This may also have a radiating appearance. with crystals up to 1 mm long stilbite(?). 5) Clear, blocky zeolite with at least two cleavages and complex twinning. Crystals up to 1 by 1.5 mm. Laumontite(?).                                                                                                                                                                                                                                                                                                                                                                                                         N
G109 0670A004W01019021003 0001 RIC Harzburgite                                                                     Porphyroclastic                                                                                     Massive peridotite                      Medium to coarse                                                                 Olivine             Clinopyroxene       Spinel              Orthopyroxene                           35   2    1    8         85   3    1    11        0.04-0.20  0.1-0.8    0.4-0.18   0.8-4.0               Fo91                                              Mg#=93                                            Cr#=50                                            En92                                                                                                Xenomorphic                                       Round, elliptical                                 Elliptical                                        Round, elliptical                                                                                   Pseudomorphed by mesh texture serpentine plus magnetite. Original fragments grains ~0.8 mm.                                                                                                                                                               Smaller grains are fragmented. Larger grains round or elliptical. Rimmed and partially replaced by serpentine.                                                                                                                                            10-90% replaced by magnetite plus ferritchromite.                                                                                                                                                                                                         Replaced by talc plus tremolite plus serpentine.                                                                                                                                                                                                                                                                                                                                                                                                                                                                     -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Lizardite           Talc                Tremolite           Magnetite           Bastite             Chrysotile                                                  44   3    trace1    5    1              Olivine                                 Opx                                     Opx                                     Spinel                                  OPx                                     Veinlets                                                                                                                Box and mesh texture serpentine replacing olivine. Bastite pseudomorphing opx. Serpentine (chrysotile?) fills some veins.                                                                                                                                 Replaces opx and bastite pseudomorphs after opx.                                                                                                                                                                                                          Thin fibrous crystals partially replace opx.                                                                                                                                                                                                              Fills veins with serpentine.                                                                                                                                                                                                                              Pseudomorphs after opx.                                                                                                                                                                                                                                   Transversal fibers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           Foliation defined by long axes of elliptical opx and spinel grains. Olivine and cpx exhibit undulatory extinction indicating that they are internally deformed. Cleavage traces in opx are gently bent.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 N
G109 0670A005R01111113015 0001 HEB Serpentinized dunite                                                            Granoblastic to cataclastic                                                                         Plutonic intrusion                      Medium                                                                           Olivine             Spinel              Orthopyroxene                                               -    trace-              95   1    4              1.5-2.8    0.5        1-2                                                                                Chromite                                                                                                                                                                                                Hexagonal, cubic                                  Granular irregular                                Elongated                                                                                                                                             Mesh texture of olivine pseudomorphs with outline of magnetite at prior margin.                                                                                                                                                                           Opaque. Almost totally replaced by magnetite forming agglomerated granules.                                                                                                                                                                               Very contorted porphyroclasts (plastic and shear deformation).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Lizardite           Magnetite           Chrysotile          Antigorite          Talc                Tremolite                                                   78   3    2    10   5    2              Olivine                                 Olivine                                 Lizardite                               Lizardite                               Serpentine                              Antigorite                                                                                                              Mesh texture of olivine forming cubic to hexagonal pseudomorphs. Hourglass texture of amorphous core.                                                                                                                                                     As streaks cutting olivine pseudomorphs. Seams to be around olivine pseudomorphs or clouds at ancient spinel replacement.                                                                                                                                 Colorless to pale brown. Transversal fibers cut to oblique shearing that transposes chrysotile into longitudinal fibers. (????)                                                                                                                           Normal, flaky habit and interlocking habit. Essentially in shear zones with deformed chrysotile veinlets.                                                                                                                                                 At outermost part of olivine pseudomorphs. Intimately associated with antigorite and/or tremolite in shear zones.                                                                                                                                         Colorless needles or fibers radiating from antigorite or chrysotile veinlets.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Sequence of events: 1) Serpentinization (lizardite plus magnetite); low temperature. 2) Talc; low/medium temperature (?). 3) Chrysotile, plus or minus magnetite (tensional cracks); low temperature. 4) Shear zones (Antigorite, plus or minus talc, plus or minus tremolite); low temperature, higher pressure. 5) Chrysotile, second generation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     N
G109 0670A005R01126128017 0001 RIC Serpentinite                                                                    Reticulate, veined                                                                                  Exterior end of pp/pm minicore                                                                                           Olivine             Spinel                                                                          0    <0.5                99(?)1                   ?          0.5-1.5                                                                                       Chromian                                                                                                                                                                                                ?                                                 Anhedral                                                                                                                                                                                                                                                                                                                                                                                                                                                          Partially to nearly completely replaced by magnetite.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Lizardite           Chrysotile          Magnetite           Antigorite          Sulfide(pyrite?)    Talc                Chlorite                                79   7    1    8    trace4.5  trace     Olivine                                 Veins                                   Veins                                   Veins                                                                           Lizardite                               Antigorite                                                                      Forms reticulate pattern, with more birefringent "strands" of network defining domains 0.2-0.5 mm wide.                                                                                                                                                   Veins are 0.2-0.5 mm wide. Chrysotile is in four larger veins. Shows a constant orientation at an average of 45 degrees to the subparallel vein walls. Walls of veins have magnetite concentrations, a pale band, in which the reticulate (SEE COMMENTS)  Concentrated along "chrysotile" vein walls, commonly penetrating along reticulate domain boundaries up to 1 mm either side of the veins.                                                                                                                  Associated with chrysotile.                                                                                                                                                                                                                               Rare grains observed associated with with magnetite in chysotile vein halo (approximately 20 microns in size).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Chrysotile veins are sub-parallel within the slide, but form an oriented anastomizing network in the hand specimen. Chrysotile continued: reticulate structure is almost absent, may be developed. This band is up to 2 mm wide each side.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              N
G109 0670A005R02052054007 0002 EIS Serpentinized dunite                                                            Porphyroblastic                                                                                     Peridotite intrusion                    Coarse porphyroblastic                                                           Olivine             Spinel              Orthopyroxene                                               -    <0.5 ~1             >90  3    5-10           1-3(?)     0.5-0.1    1-4                                                                                Chromite                                          Enstatite                                                                                                                                             Polygonal                                         Irregular                                         Tabular                                                                                                                                               Mesh texture of olivine pseudomorphs hexagonal with discrete outlines of magnetite.                                                                                                                                                                       Opaque, nearly totally replaced by magnetite.                                                                                                                                                                                                             Highly deformed porphyroblasts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Chlorite            Lizardite           Magnetite           Talc                Antigorite          Chrysotile          Tremolites                              2    72   5    3    15   2    trace     Antigorite                              Olivine                                 Opx, olivine. spinel                    Opx                                     Serpentine                              Serpentine                              Antigorite                                                                                                                                                                                                                                                                                                                                Mesh texture replacing olivine, sometimes forming opx pseudomorphs.                                                                                                                                                                                       Outlines former olivine crystals. Concentrated in shear spinel zones and along cleavage planes of opx.                                                                                                                                                    Surrounds and replaces opx and olivine.                                                                                                                                                                                                                   Essentially in shear zones and tensional filaments and veinlets. Interlocking pattern.                                                                                                                                                                    In veins.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             N
G109 0670A006R01004006001 0003 KOM Clinopyroxene-bearing harzburgite                                               Porphyroclastic                                                                                     Massive peridotite                      Medium-coarse                                                                    Olivine             Clinopyroxene       Spinel              Orthopyroxene                           20   2    <1   9         85   2    <1   12        0.04-0.4   0.6-1.4    0.04-0.5   1.6-4.2               Fo90                                              Mg#92                                                                                               En91                                                                                                Anhedral                                          Rounded                                           Anhedral                                          Round, slightly elongate                                                                            Undulatory extinction in olivine. Preserpentinization olivine fragments 0.4-1.2 mm in size.                                                                                                                                                               Contain exsolution lamellae of opx. Rims partially serpentinized.                                                                                                                                                                                         Partially to completely replaced by magnetite.                                                                                                                                                                                                            Oscillatory extinction. Gently bent cleavage traces.                                                                                                                                                                                                                                                                                                                                                                                                                                                                 -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Lizardite           Talc                Magnetite           Chrysotile          Bastite                                                                         64   4    1    2    2                   Olivine                                 Opx                                     Olivine                                 Lizardite                               Pyroxene                                                                                                                                                        Mesh texture serpentine replacing olivine. Bastite pseudomorphs after opx.                                                                                                                                                                                Rims opx and surrounding serpentine.                                                                                                                                                                                                                      Partially replaces spinel. Magnetite plus serpentine replaces olivine.                                                                                                                                                                                                                                                                                                                                                                                                                                              Pseudomorphs after pyroxene.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Slight to moderate granulation around opx porphyroblasts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               N
G109 0670A007R01043045007A0004 HEB Serpentinite                                                                    Cataclastic after porphyroclastic harzburgite, multiple veined alteration assemblage                Plutonic intrusion                      Fine                                                                             Olivine             Spinel              Orthopyroxene       Clinopyroxene                           -    trace-    -         80   1    ?    ?         1-2        1          -          -                                                                       Hercynite, picotite                                                                                                                                                                                     Polygonal                                         Subhedral                                         -                                                 -                                                                                                   Mesh texture and hour-glass texture of lizardite with magnetite seam.                                                                                                                                                                                     Almost totally altered to magnetite.                                                                                                                                                                                                                      Now replaced by bastite which preserves the initial morphology and pophyroclastic texture.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Chlorite            Tremolite           Magnetite           Lizardite           Antigorite          Chrysotile                                                  10   5    5    50   20   10             Antigorite                              Antigorite                              Spinel                                  Olivine, opx                            Lizardite                               Veinlets                                                                                                                Magnesium-rich (colorless) with anomalous copper to blue birefringence.                                                                                                                                                                                   Acicular or fibrous in a radiate pattern. Growing at the expense of antigorite in or near deformed chrysotile veinlets.                                                                                                                                   Fills veins and pockets and replaces granular spinel.                                                                                                                                                                                                     Pseudomorphs after olivine and pyroxene. Polygonal morphology of olivine recognized in a few places.                                                                                                                                                      Plate ot flake-like interlocking texture. In shear planes, antigorite is parallel to the direction of the shear zone.                                                                                                                                     Fills open tensional fractures that are deformed within shear planes and partially replaced by antigorite. Late-stage chrysotile veinlets cross cut the shear planes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Sequence of events: 1) Lizardite plus magnetite after olivine. 2) Chrysotile in dilation fissures (fibrous). 3) Antigorite (in shear planes). 4) Chlorite plus tremolite (fibrous, prismatic) partially replace antigorites in lense-shaped shear planes. 5) Late stage open fissures filled by chrysotile.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             N
G109 0670A009R01107109014 0006 GRO Serpentinized peridotite                                                        Cataclastic                                                                                         Probable fault zone                     Fine to coarse                                                                   Olivine             Orthopyroxene       Clinopyroxene       Spinel                                  0    5    ?    ?         90   10   ?    ?         -          -          -          -                                                                                                                                                                                                                                                                               -                                                 -                                                 -                                                 -                                                                                                   Completely altered to serpentine and other metamorphic minerals.                                                                                                                                                                                          Deformed, cataclastic. Surrounded by talc and serpentine rims. Cut by antigorite veins.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  -                                                                                                   -                        -                        -                                                                                                                                                                                                                                                                                                                -                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Vesicles                   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Chlorite            Tremolite           Lizardite           Bastite             Antigorite          Chrysotile          Magnetite                               30   30   9    8    12   5    1         Olivine                                 Olivine                                 Olivine                                 Olivine                                 Lizardite, in veins                     Lizardite                               Olivine(?)                                                                      Intergrown with tremolite. Acicular, micron-sized crystals.                                                                                                                                                                                               Intergrown with chlorite. Acicular crystals, 10-20 microns wide.                                                                                                                                                                                          Lizardite patches.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            In veins up to 2 mm wide and 1 cm long.                                                                                                                                                                                                                   Occurs with lizardite.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Primary minerals almost completely reacted by metamorphism. A few relict, cataclastized orthopyroxene porphyroclasts are surrounded by talc plus serpentine halos. Patchy areas of lizardite plus magnetite are surrounded by a reaction zone of tremolite plus chlorite, and cut by chrysotile veins. Some antigorite veins cut lizardite. Both the serpentine assemblage and the tremolite plus chlorite have been cataclastically deformed.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          N