"168-1025B-11X-CC (Piece 2, 028-040 cm)" ROCK NAME: Aphyric plagioclase-pyroxene-olivine basalt GRAIN SIZE: Aphanitic: microcrystalline TEXTURE: Sheaf-spherulitic to intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine Tr Tr 0.1-0.4 Sub- to euhedral Replaced by secondary minerals. Plagioclase Tr Tr <=0.8 Euhedral laths Unzoned to oscillatory zoned. Clinopyroxene Tr Tr 0.8 Euhedral "One crystal, attached to a plagioclase lath." GROUNDMASS Plagioclase 14 14 0.1-0.2 Microlitic laths "Equant and elongate laths, commonly hollow and skeletal; radiating clusters intergrown with clinopyroxene and/or olivine." Olivine 0 2 0.1-0.4 Subhedral-euhedral See comments above. Clinopyroxene 9.4 9.4 0.1-0.2 Anhedral granular Intergrown with radiating plagioclase. Mesostasis 71.4 71.4 Sheaf-spherulitic plagioclase and clinopyroxene with interstitial skeletal magnetite (10-20 microns across) and numerous 2-10 microns (and one 250 microns) diameter pyrite globules. Pyrite/pyrrhotite Tr Tr <=0.02 Granular "In mesostasis; one grain, 0.12mm across, is a lamellar pyrite-pyrrhotite(?, anisotropic) intergrowth." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay 2 "Olivine, veinlets and vesicles." Mg-saponite + celadonite Fibrous. Olivine is apparently completely replaced by green-orange clay followed by pale brown clay; veinlets are several microns wide and filled with pale green to green-orange clay; whilst vesicles are thinly lined by pale brown to colorless clay. VESICLES/ CAVITIES PERCENT DISTRIBUTION SIZE (mm) FILLING SHAPE COMMENTS: Vesicles 2.2 Even 0.2-0.6 Clay lining Round to irregular. COMMENTS: "168-1025B-11X-CC (Piece 3, 028-040 cm)" ROCK NAME: Sparsely phyric plagioclase-pyroxene-olivine basalt GRAIN SIZE: Aphanitic: microcrystalline to cryptocrystalline TEXTURE: Variolitic to subvariolitic PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 1 0.2-0.4 Euhedral Replaced by secondary minerals. Plagioclase 0.6 0.6 <=1.5 Subhedral laths Normal zoning and rare oscillatory zoning. Some have straight edges whilst others appear to be partially resorbed with respect to groundmass glass. Clinopyroxene 0.2 0.2 1.9 Euhedral "One crystal; simply zoned and twinned, partially encloses plagioclase phenocrysts; the rim encloses euhedral plagioclase and magnetite microlites." Pigeonite 0.8 0.8 0.1-0.3 Euhedral "Concentrated in one area of the thin section (could potentially be cpx). Low birefringence, biaxial positive 2V~30¡. " GROUNDMASS Plagioclase 9 9 0.1-0.2 Microlite laths "Hollow, swallowtail and skeletal; radiating clusters intergrown with clinopyroxene. " Olivine 0 0.2 0.2-0.4 Euhedral See comments above Clinopyroxene 5.6 5.6 <=0.1 Euhedral to equant Individual crystals and granular aggregates with plagioclase and altered olivine. Mesostasis 80.4 80.4 Subvariolitic. Trace amount of pyrite globules (<=20 microns). Glass 0.8 0.8 Fresh quenched margin (1-2mm thick) with varioles. Medium to dark brown. Pyrite Tr Tr <=0.05 Granular "In mesostasis, plagioclase." Chalcopyrite Tr Tr <=0.05 Granular In mesostasis. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 1.2 "Olivine, veinlets and vesicles" Fibrous to granular Olivine is replaced by granular to fibrous green-orange to yellow-brown clay. Veinlets (<=30 microns wide) are filled with pale brown clay. Vesicles are thinly lined by brown-orange clay followed by pale brown clay. Iddingsite Tr "Olivine, veinlets and vesicles" One vesicle is thickly lined with iddingsite followed by green-orange clay followed by pale clay. Calcite Tr Olivine Pyrite Tr Clay veins and vesicles 0.1-0.2 Concentrated near the glassy rim. Also occurs along microcracks and some vesicles. Postdates the clay linings of vesicles. VESICLES/ CAVITIES PERCENT DISTRIBUTION SIZE (mm) FILLING SHAPE COMMENTS: Vesicles 1.4 0.1-0.2 COMMENTS: "168-1025C-1R-01 (piece 3, 15-20cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic; cryptocrystalline TEXTURE: Intersertal; vesicular PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr <=1.4 Euhedral Simply zoned. GROUNDMASS Plagioclase 24.3 24.3 0.2-0.6 Euhedral-subhedral "Present as euhedral-subhedral laths, as well as quench crystals (swallowtails, hollow crystals etc.)." Olivine 0 2.4 0.1-0.3 Euhedral Completely replaced by clay (saponite?). Clinopyroxene 16.3 16.3 0.1-0.3 Anhedral Anhedral intergrowths with plagioclase. Opaque oxide 1.8 1.8 <=0.1 Skeletal Present in the mesostasis. Pyrite Tr Tr <=0.005 Blebs Occurs as round globules inside plagioclase crystals and the mesostasis. Mesostasis 52.3 54.9 Cryptocrystalline mass. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 5.2 Olivine; mesostasis; vesicles Pseudomorphs olivine microphenocrysts; lines vesicles (0.005-0.02mm layers). Pyrite Tr Vesicles Very thin (<=0.003mm) partial vesicle lining before clay in one vesicle. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.4 Even <=0.3 None Round Segregation vesicles 0.4 Even <=0.5 Mesostasis Round COMMENTS: "168-1025C-1R-01 (piece 8, 48-59cm)" ROCK NAME: Aphyric basalt (from near quenched margin) GRAIN SIZE: Aphanitic; cryptocrystalline TEXTURE: Locally glomeroporphyritic; quench microphenocrysts in intersertal mesostasis. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase 1 1 0.5-0.8 Euhedral Single laths isolated in mesostasis and associated with small agglomerates of granular pyroxene; present as glomerocrysts. GROUNDMASS Plagioclase 7.3 7.3 <=0.6 (Ave 0.3) Euhedral-subhedral "Present as euhedral-subhedral laths and stubby crystals, as well as quench crystals (swallowtails, hollow crystals etc.). Occurs as single grains or within glomerocrysts with pyroxene." Olivine 0 1.3 0.2-0.4 Euhedral Completely replaced by clay (saponite?). The crystals are present as pseudomorphed outlines +/- bands of fibrous-granular clay within an otherwise empty shape. Clinopyroxene 4.3 4.3 0.1-0.3 Euhedral-anhedral Present as euhedral microphenocrysts as well as anhedral intergrowths with plagioclase. Pyrite/Pyrrhotite Tr Tr Skeletal-anhedral "Occurs as discrete skeletal laths (<=0.06mm), round globules inside plagioclase crystals and angular grains in the mesostasis." Mesostasis 86.1 86.1 "Varies from dense, brown sub-isotropic material, to a gray-brown cryptocrystalline mass." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clays 1.3 Olivine "Pseudomorphs olivine microphenocrysts; most has been ground away during polishing, although a fine lining is still present along the grain boundary." Pyrite Tr Mesostasis; olivine "Forms granular grains in mesostasis, as well as occurring within the clay pseudomorphing olivine." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.9 Even <=0.35 None Round COMMENTS: "The mesostasis texture varies from being dense and sub-isotropic at the quenched margin, passing down into a subvariolitic section with a weak " honeycomb to sheaf-spherulitic texture. Around 37% of all phenocrysts and groundmass minerals are part of glomerocrysts. "168-1025C-1R-02 (piece 3, 16-20cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic; microcrystalline TEXTURE: Intergranular-intersertal; vesicular PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 Tr 0.3-0.5 Euhedral Completely replaced by cryptocrystalline brown clay (saponite?). Plagioclase 1.1 1.1 0.5-0.8 Anhedral - subhedral "Stubby, irregular crystals exhibiting simple zoning." GROUNDMASS Plagioclase 43.2 43.2 0.2-0.5 (Ave 0.4) Subhedral-anhedral "Elongate laths; majority of crystals are subhedral, forming a network of laths as well as stellate clusters. Some hollow/skeletal small laths occur." Olivine 0 1.8 <=0.2 Euhedral-subhedral Completely altered to cryptocrystalline brown clay (saponite?). Occur interstitially to plagioclase. Minor opaque inclusions occur in some grains. Clinopyroxene 28.4 28.4 0.15-0.4 (Ave 0.2) Subhedral-anhedral "Pale brown color in PPL; occurs interstitially to plagioclase laths, as well as at the center of stellate plagioclase clusters. Some grains contain minor opaque inclusions." Opaques 9.1 9.1 <=0.2 (Ave 0.05) Euhedral-skeletal "Majority of opaques are magnetite and ilmenite (<=0.2mm), along with a trace amount of pyrite (<=0.03mm), occurring as discrete grains and small rods (<=0.04mm) in the mesostasis. Ilmenite typically forms skeletal laths." Mesostasis 3.1 13.2 Occur as irregular gray-brown cryptocrystalline patches with minor feathery px(?) plumes. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 15.1 Olivine; vesicles "Brown, cryptocrystalline to fibrous; completely pseudomorphs olivine and lines vesicles." Zeolite Tr Vesicles "Forms small (<=0.09mm), euhedral, colorless crystals +/- a fine (<=0.05mm)) band infilling parts of some vesicles. The zeolite has then been sequentially lined by pale brown fibrous saponite." Pyrite Tr Vesicles Occurs as discrete grains (c.0.001mm) within the clay lining of vesicles. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 6.4 0.6-1.6 Clay Round Majority of round vesicles are lined by a <=0.05mm layer of fibrous saponite. Vesicles/cavities 1.6 0.3-0.7 Clay + zeolite Irregular - ovoid Many contain a partial fill of mesostasis +/- a <=0.05mm layer of zeolite +/- euhedral zeolite crystals in clay +/- a <=0.05mm layer of fibrous saponite. COMMENTS: "168-1025C-2R-01 (piece 17, 143-147cm)" ROCK NAME: Aphyric basalt "GRAIN SIZE: Aphanitic, microcrystalline" "TEXTURE: Intergranular, locally intersertal" PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase 0.2 0.2 0.6-1.4 Euhedral Stubby laths in monomineralic glomeroporphyritic clots; strongly zoned at edges. GROUNDMASS Plagioclase 45.8 48.6 0.5-1.0 Subhedral-anhedral Microlaths; strongly zoned. Olivine 0 3.6 0.5-1.2 Euhedral-subhedral Partially encloses plagioclase + clinopyroxene clots; completely replaced by brown clay (saponite). Clinopyroxene 27.1 27.1 0.3-0.5 Euhedral-anhedral "Intergranular, occurring as discrete (0.3-0.5mm) grains, as well as a granular mass (<=0.1mm) within glomeroporphyritic clots with plagioclase laths." Magnetite 7.2 7.2 0.05-0.3 (Ave 0.1) Anhedral Scant lamellae of ilmenite enclosed in magnetite grains. Pyrite/pyrrhotite Tr Tr 0.03-0.05 Anhedral-globular Accounts for c.10% of all opaque grains. Mesostasis 0 13.3 Interstitial aggregates of microcrystalline to cryptocrystalline material with microcrysts of plagioclase + opaques + clay; some feathery cryptocrystalline plumes (cpx?). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite (brown) 19.7 "Olivine; mesostasis, skeletal plagioclase" "Dark olive brown, massive clay with masked interference colors; granular to cryptocrystalline texture." Saponite (green) Tr Olivine; mesostasis "Pale yellow-green; fibrous to granular, surrounds brown saponite-replaced olivine microphenocryst." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: None COMMENTS: Some pale yellow-green clay (saponite?) occurs in one corner forming a band around some mesostasis and an olivine microphenocryst which have been replaced by brown saponite. "168-1025C-2R-02 (piece 11b, 139-142cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Fine grained. TEXTURE: Intersertal to intergranular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr 0.6-1.6 Euhedral Stubby laths (much less elongate than groundmass laths); strongly zoned. GROUNDMASS Plagioclase 40.6 40.6 0.2-1.2 Subhedral-anhedral Microlaths and prisms; strongly zoned. Olivine 0 3.6 0.1-0.4 Euhedral-subhedral Completely replaced by olive-brown clay (saponite). Clinopyroxene 27 28.6 0.1-0.3 Anhedral-subhedral "Intergranular, occurring as discrete grains." Opaques 7.8 7.8 0.05-0.3 Skeletal-subhedral Interstitial magnetite/maghemite + some globular sulfides. Mesostasis 1.9 19.4 Interstitial; mostly replaced by clay. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 22.7 Olivine; mesostasis Massive to cryptocrystalline aggregates. Carbonate Tr Olivine Quartz Vein Not included in point count; chalcedony to drusy quartz. Pyrite Tr Associated almost exclusively with clay alteration. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: None COMMENTS: "Composite vein (1.5mm) with orange-brown mixture of clay and iddingsite in the outer rim of the vein, and quartz in the center. Quartz occurs as aggregates of" "euhedral crystals increasing in size towards the middles of open vugs. In these, chalcedonic quartz forms near the margin, changing to euhedral and drusy quartz" in the middle ( <=0.3mm). Patches (0.2-0.3mm) of pale brown clay are mixed with the quartz. Spots of dark orange iddingsite are widespread within the veins. "168-1025C-2R-04 (piece 12, 54-58cm)" ROCK NAME: Aphyric basalt "GRAIN SIZE: Aphanitic, cryptocrystalline to microcrystalline" TEXTURE: Hypocrystalline; intersertal; patches of sheaf-spherulitic to plumose mesostasis. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 Tr 0.4-0.8 (Ave 0.6) Euhedral Completely replaced by fibrous brown clay (saponite?). The clay preserves the outline of the crystals as well as forming fibrous bands within the crystal (following fracture planes?). Plagioclase Tr Tr 0.6-1.6 (Ave 0.8) Euhedral Laths and stubby crystals occur singly and within crystal clots; minor simple zoning. GROUNDMASS Plagioclase 26.4 26.4 0.1-0.6 (Ave 0.2) Subhedral-anhedral Forms microphenocrysts which occur singly and within stellate clusters. <=0.2 Euhedral Forms whole and quenched (swallowtail; hollow) microlaths and microlites. Olivine 0 0.8 0.2-0.3 (Ave 0.2) Euhedral Completely replaced by brown clay (see comments above). Clinopyroxene 22 22 0.1-0.3 (Ave 0.1) Anhedral-subhedral Occurs singly and at the center of microglomeroporphyritic clots of plagioclase + opaques; some bowtie structures with plagioclase. Opaques 4.6 4.6 0.01-0.08 (Ave 0.05) Euhedral-skeletal Mostly magnetite plus some minor pyrite (<=0.04mm); some skeletal laths of magnetite (ilmenite?) extend up to 0.15mm. Mesostasis 36 45.2 "Brown, intersertal, cryptocrystalline patches. Some areas have a sheaf-spherulitic +/- plumose texture, with feathery plumes of cryptocrystalline cpx(?)." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 10 Olivine; vesicles; mesostasis "Brown, fibrous; replaces olivine and partially lines vesicles. Some vesicles contain rods of saponite (fibers extend perpendicular to rod axis), extending into the center of the vesicle." Carbonate Tr Vesicles Aragonite needles (<=0.28mm long) extend into the center of some vesicles. These needles are lined by fine fibers of saponite. Zeolites Tr Vesicles "Forms a discontinuous layer (<=0.01mm thick) of blocky crystals at the outer edge of some vesicles, which has then been coated by a layer of fibrous clay (saponite?)" VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 1 0.3-0.5 Clay +/- carbonate Round-irregular Lined by <=0.03mm fibrous saponite +/- rods of saponite extending into center. Some have semicircular stellate clusters of aragonite needles attached to the rim. Segregation vesicles Tr <=0.4 Mesostasis +/- clay Round Partially to completely filled by mesostasis +/- opaque rods. Partially filled vesicles have <=0.02mm layer of fibrous saponite after the mesostasis fill. COMMENTS: Irregular gas vesicles/cavities (<=0.8mm) are empty. "168-1025C-3R-01 (piece 5, 19-27cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic to fine grained. TEXTURE: Hypocrystalline; intersertal; sheaf-spherulitic. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase 0.2 0.2 0.4-1.6 (Ave 0.8) Euhedral-subhedral Laths and stubby crystals; some oscillatory zoning. GROUNDMASS Plagioclase 18.4 18.4 0.05-0.6 (Ave 0.3) Subhedral-skeletal "Microlaths and microlites, plus some quench crystals form patches of intersertal texture; granular pyroxene commonly occurs the edges of the large plagioclase grains." Olivine 0 2.2 0.15-0.4 (Ave 0.25) Euhedral-subhedral Completely replaced by brown-green granular to fibrous saponite; center of all grains have been plucked out (by polishing?). Clinopyroxene 15 15 0.05-0.3 (Ave 0.2) Subhedral-anhedral "Present as discrete subhedral (0.1-0.3mm) crystals, granular (<=0.05mm) grains in the groundmass and granular crystals (0.05-0.15mm) in glomeroporphyritic clots." Opaques 0.01-0.1 (Ave 0.05) Granular-skeletal "(Abundance has been included in mesostasis count.) Mostly magnetite with minor granular and globular pyrite (<=0.01mm), disseminated throughout the groundmass and within and between crystals." Mesostasis 63.2 63.2 "Feathery sheafs of cryptocrystalline material (cpx?), as well as dark brown, massive areas; forms patches throughout the section." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 2.2 Olivine; vesicles "Massive saponite is brown; fibrous saponite is brown-green. Massive saponite replaces the margins and along fractures in olivine, whilst fibrous saponite replaces the center of olivine and lines vesicles." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 1 Even 0.4-0.5 Clay Round-ovoid Lined by fibrous brown-green saponite (<=0.04mm layers). Segregation vesicles (incl. above) Even <=0.6 Mesostasis + clay Round "Partially to completely filled by mesostasis. Partially filled vesicles have gas bubble inside lined by fibrous saponite, as above." COMMENTS: "A continuum exists between the segregation and gas vesicles from: i) completely filled segregation vesicles, filled by mesostasis + opaque needles + microlites of" "plagioclase + pyroxene; ii) partially filled segregation vesicles, as in (i); iii) geopetel infills of mesostasis (<=0.1mm thick) within vesicles, most of which occur at base" "of vesicle according to the way-up direction on the section (some however, are discordant). The geopetel infill and rest of the vesicle is then lined by a <=0.04mm layer of" "fibrous brown-green saponite; and iv) empty gas vesicles, lined by a <=0.04mm layer of fibrous brown-green saponite." Minor crystal clots of plagioclase + pyroxene occur within the section. "168-1025C-3R-01 (piece 7, 30-34cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic; cryptocrystalline. TEXTURE: Intersertal; hyalopilitic PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase 0.4 0.4 <=1.7 Euhedral-subhedral Stubby laths; weak zoning. GROUNDMASS Plagioclase 9.9 9.9 0.1-0.7 (Ave 0.3) Subhedral-skeletal "Microlaths and microlites, plus some quench crystals." Olivine 1 2.2 0.1-0.3 Euhedral Partially replaced by brown saponite and carbonate. Clinopyroxene 4 4 0.1-0.3 Anhedral Intergrown with plagioclase. Opaques 0.8 0.8 <=0.01 Granular-skeletal Mostly magnetite with minor pyrite/pyrrhotite disseminated throughout the groundmass. Mesostasis 82.1 82.1 Cryptocrystalline material with granular pyroxene + opaques. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 1.4 Olivine; vesicles "Filamentous, open mats partially fill vesicles and replace olivine." Carbonate Tr Olivine Pyrite/pyrrhotite Tr Vesicles Associated with clay; <=0.03mm composite grains. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.8 Even <=0.6 Filamentous clay Round COMMENTS: "168-1025C-4R-01 (piece 4, 19-27cm)" ROCK NAME: Aphyric pyroxene-plagioclase-olivine basalt GRAIN SIZE: Aphanitic: microcrystalline to cryptocrystalline. TEXTURE: Intersertal to intergranular; vesicular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr <=0.75 (Ave 0.6) Subhedral-euhedral stubby laths Strong zoning which may be oscillatory. Many euhedral phenocrysts have subhedral to oval shaped cores. GROUNDMASS Plagioclase 26 26 <=0.6 Subhedral-anhedral laths Seriate texture; hollow and swallowtail crystals are common. Olivine 0 2.2 0.25-0.4 (Ave 0.3) Euhedral "Totally replaced by pale brown clay (saponite), with a granular to fibrous texture." Clinopyroxene 32.2 32.2 0.05-0.2 Subhedral-anhedral "Granular grains, intergrown with plagioclase, as well as intergranular grains." Opaque oxides 7.8 7.8 <=0.1 (Ave 0.05) Anhedral-skeletal Isotropic; magnetite +/- maghemite (based on palaeomagnetics). Pyrite Tr Tr <=0.03 Globular Globules in the mesostasis. Mesostasis 26.8 30.4 Cryptocrystalline with granular cpx(?) + opaque rods and dendrites; patchy alteration to brown clay (saponite?). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 5.8 Olivine; vesicles; mesostasis "Brown granular saponite and olive to tan brown fibrous saponite are present replacing olivine and patches of mesostasis, and lining the vesicles (see below)." Pyrite Tr Vesicles; olivine "Occurs are globular grains within clay replacing olivine, as well as in the clay which lines some vesicles." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas 1.4 Even 0.2-0.75 Clay Round Thinly lined by fibrous clay. Segregation Tr Even 0.4-0.5 Mesostasis Round Varying from partial (meniscus) fill to completely filled. Cavities Tr Even <=0.5 Clay Irregular "Thinly lined by fibrous clay, identical to the gas vesicles. One cavity is connected to a vesicle by a tiny inlet." COMMENTS: "The typical vesicle/cavity lining consists of a 0.015mm layer of dark brown fibrous clay (with dark brown-orange birefringence), followed by a <0.005mm layer" "of pale tan brown fibrous clay (first order birefringence). Pyrite is generally absent, although one or two grains were observed in the mesostasis layer underlying" the clay. "168-1025C-4R-01 (piece 16a, 123-125cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: microcrystalline to fine grained. TEXTURE: Intergranular to intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS None GROUNDMASS Plagioclase 42.8 42.8 0.3-1.5 (Ave 0.3) Subhedral Elongate laths; strongly zoned. Olivine Tr 2.4 0.1-0.3 (Ave 0.3) Subhedral "Completely to partially replaced by massive to cryptocrystalline olive-brown to olive-green clay; some relict, fresh olivine remains in a few grains." Clinopyroxene 31.4 31.4 0.1-0.6 (Ave 0.2) Anhedral-subhedral Intergranular. Opaques 6.2 6.2 0.05-0.5 (Ave 0.2) Euhedral-anhedral "Mostly subhedral magnetite, with a trace amount of globular pyrite/pyrrhotite. Pyrite/pyrrhotite is only present within the mesostasis." Mesostasis 4.3 17.2 Interstitial cryptocrystalline brown-gray material partially altered to brown clay (saponite?). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (saponite?) 15.3 Olivine; mesostasis "The saponite is more massive and olive-green to brown when replacing olivine, compared to that which replaces the mesostasis, where it is fibrous and brown-gray." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: None COMMENTS: "168-1025C-4R-03 (piece 1d, 24-28cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: microcrystalline to fine grained. TEXTURE: Intergranular to intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr 0.6-1.6 (Ave 0.8) Euhedral-subhedral Mostly euhedral laths + stubby crystals; simple zoning. GROUNDMASS Plagioclase 37.4 37.4 0.2-0.7 (Ave 0.45) Euhedral-subhedral Elongate laths form an intergranular network; some simple zoning. Olivine 0 2.8 0.2-0.4 (Ave 0.2) Euhedral Completely replaced by cryptocrystalline brown-green saponite. Some crystals contain an abundance of <=0.02mm blebs of opaques. Clinopyroxene 35.6 35.6 0.1-0.4 (Ave 0.2) Subhedral-anhedral "A few euhedral crystals; glass inclusions occur in some crystals forming trails parallel to the crystal margins, or irregular patches within the core." Opaques 8.8 8.8 <=0.3 (Ave 0.2) Euhedral-anhedral "Majority are magnetite, some of which are euhedral and skeletal. There is also a trace amount of globular pyrite (<=0.04mm) within the mesostasis." Mesostasis 3.7 15.4 Brown-gray cryptocrystalline material; partially replaced by saponite. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 14.1 Olivine; mesostasis "Brown-green to brown-gray cryptocrystalline clay replacing olivine and interstitial mesostasis material, respectively." Carbonate Tr Olivine "Accessory to saponite, replacing olivine." Zeolites 0.4 Mesostasis "Clear, fibrous aggregates replace interstitial mesostasis (+/- olivine), enclosing 0.002-0.005mm anhedral sulfide grains." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: None COMMENTS: "168-1025C-5R-01 (piece 7, 38-42cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Fine grained. TEXTURE: Intergranular to intersertal; vesicular PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 0.7 <=1.6 (Ave 1.2) Subhedral-euhedral Completely replaced by fibrous saponite +/- talc (only near talc vein). Plagioclase 0.5 0.5 0.8-1.2 (Ave 0.8) Anhedral-subhedral Stubby crystals and laths; some simple zoning. GROUNDMASS Plagioclase 39.4 39.4 0.2-0.8 (Ave 0.4) Subhedral laths Minor parallel orientation perpendicular to the way up. Some stellate clusters with pyroxene at core. Olivine 0 3.5 0.2-0.4 (Ave 0.4) Subhedral-interstitial Completely replaced by fibrous-granular olivine-brown saponite +/- fibrous talc +/- zeolites. Clinopyroxene 26.4 26.4 0.1-0.4 (Ave 0.3) Subhedral-anhedral Grains occur singly and intergrown with plagioclase; interstitial. Opaque oxides 9.2 9.2 0.02-0.1 (Ave 0.04) Subhedral-anhedral Occur in groundmass + pyroxene + olivine; contain lamellae of ilmenite. Opaque sulfides Tr Tr 0.3-0.5 (Ave 0.3) Subhedral-anhedral Occurs in groundmass; one grain has a triangular 0.05mm chalcopyrite grain in it. Mesostasis 0 20.3 "Interstitial, all replaced by brown to olive brown saponite + colorless zeolite +/- chlorite/smectite." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 24.5 Olivine; mesostasis Brown to olive-brown color; fibrous to granular. Only replaces pyroxene next to talc-filled fracture. Zeolites Tr Mesostasis +/- olivine "Forms colorless, spherulitic masses, replacing the mesostasis +/- olivine. 0.005-0.015mm opaque oxides are held in zeolite." Chlorite/smectite Tr Mesostasis Blue-green fibrous patches in the mesostasis; blue-gray birefringence. Talc Tr Vein; olivine Small patch in fracture; fibrous. Also replaces olivine near the fracture. Pyrite/Pyrrhotite Tr Vesicles <=0.4mm subhedral-anhedral grains in some vesicles. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas 14.2 Even 0.9-3.2 (Ave 0.9) Empty; pyrite Round-irregular Some have minor rim of clay; others contain some sulfide grains. COMMENTS: "In the olivine pseudomorphs, saponite +/- talc forms circular bundles of fibers. Some crystals are replaced by granular saponite. Saponite has generally been plucked" out by polishing. "168-1025C-5R-02 (piece 3, 41-45cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic; microcrystalline TEXTURE: Intergranular to glomeroporphyritic. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS None GROUNDMASS Plagioclase 39 39 0.3-1.5 Euhedral laths Strongly zoned; forms randomly orientated laths as well as stellate clusters. Olivine 0 3 0.2-0.4 Subhedral Completely altered to olive-green to olive-brown clay (saponite?). Clinopyroxene 31.8 31.8 0.1-0.5 Subhedral-anhedral Intergranular; occurs as anhedral granules (<=0.1mm) at the center of plagioclase stellate clusters. Opaque oxides 8.8 8.8 0.1-0.5 Subhedral Interstitial; magnetite and/or maghemite. Opaque sulfides Tr Tr <=0.05 Globular Occurs in the mesostasis; pyrite and/or pyrrhotite. Mesostasis 4.4 17.4 "Interstitial, brown to brown-gray cryptocrystalline, feathery material." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 16 Olivine; mesostasis "Brown to brown-gray color. Olivine is replaced by brown to brown-green cryptocrystalline saponite, whilst the mesostasis is replaced by brown to brown-gray cryptocrystalline clay." Zeolites Tr Mesostasis +/- olivine "Forms colorless, granular to spherulitic, isotropic masses, replacing the mesostasis +/- olivine." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: None COMMENTS: "The mesostasis forms larger, irregular patches (maximum length <=4mm; average 0.8mm), than in the thin section from 1025C-4R. The texture is influenced by " "<=1.6mm ovoid masses of granular (<=0.1mm) pyroxene + plagioclase, with larger (0.3-0.8mm) plagioclase laths (+/- subhedral pyroxenes) radiating out from the center."