"168-1027B-60X-CC (piece 5, 33-38 cm)" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: cryptocrystalline to microcrystalline TEXTURE: Pilotaxitic; intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 2.6 <=0.5 Euhedral-subhedral Completely replaced by secondary minerals - clay and calcite. Plagioclase Tr Tr <=0.5-0.6 Euhedral-subhedral Contains small spinel inclusions. GROUNDMASS Plagioclase 30.4 30.4 <=0.15 Microlitic laths "Exhibit quench textures (hollow crystals, swallowtails)." Mesostasis 54.4 63 Cryptocrystalline to microcrystalline; ghost/skeletal pyroxenes and magnetite may be discernible; patchy alteration to birefringent clays. Pyrite Tr Tr <=0.04 "Granular, subhedral" In mesostasis. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (poss. saponite?) 11.4 Mesostasis. Outer rim of vesicles. Cryptocrystalline to fibrous. Gray to yellow fibrous; low birefringence Chlorite(?) Groundmass minerals (mainly pyroxene). Lining vesicle. Fibrous White to yellow brownish in ppl. Gray to yellow in XPL. Calcite 0.8 Vesicles; mafic phases; mesostasis. Patchy to granular. Infilling of gas vesicles; replacement of mafic phases with phyllosilicates. Pyrite Tr Anhedral to euhedral. Forms discrete irregular grains within the groundmass and along the edge of vesicles after the clay lining but before the calcite infill. Zeolites(?) Tr Mafic crystals Anhedral to euhedral Pseudomorphs whole or part grains of primary mafic mineral grains. VESICLES/ CAVITIES PERCENT PERCENT ORIGINAL SIZE (mm) FILLING SHAPE COMMENTS: Gas Vesicles 1.4 1.8 <=0.3 Clay; calcite; (chlorite?). Spherical to irregular "Gas vesicles may be lined by a fine (5-10 micron) rim of fibrous phyllosilicate (saponite?), followed by a partial to complete infill of radial to sparry calcite." Segregation vesicles 1.6 1.8 <=1.3 Filled wholly or partially by groundmass material with feathery pyroxene and granular iron oxides; commonly with a gas vesicle (see description above). COMMENTS: "168-1027B-61X-CC, 13-15 cm" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: cryptocrystalline to microcrystalline TEXTURE: Intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr <=0.5 Euhedral-subhedral Contains small spinel inclusions Mafic minerals (olivine? + pyroxene?) 0 3 <=0.8-0.3 "Euhedral-subhedral, skeletal" Completely replaced by secondary minerals including clay (Fe-saponite) + calcite. (Original mineralogy based upon euhedral grain shape.) GROUNDMASS Plagioclase 30.4 30.4 <=0.2 Microlitic laths "Exhibit quench textures (hollow crystals, swallowtails)" Mafic phases (olivine? + pyroxene?) 0 <=7 <=0.1 Subhedral-anhedral "Completely replaced by secondary minerals, the most common being calcite (c.5%) and clay (Fe-saponite; c.2%)." Spinel Tr Tr <=0.005 Euhedral Associated or partially enclosed in microlitic plagioclase laths Pyrite Tr Tr <=0.03 Granular In mesostasis. Magnetite Tr Tr <=0.05 Euhedral-subhedral Disseminated in the groundmass Mesostasis 54 54 Cryptocrystalline to microcrystalline; ghost/skeletal mafic minerals and euhedral to subhedral magnetite; some of the groundmass is replaced by a yellowish-brown clay mineral (fibrous to patchy). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (Fe-saponite?) 10 Mesostasis. Outer rim of gas vesicles. Patchy to fibrous Colorless to yellow/light brown; low birefringence. Calcite 2.4 Vesicles; mafic minerals; vein. Anhedral to subhedral. "Completely replaces mafic mineral phenocrysts and microlites, as well as infilling the center of vesicles (see below). " Chlorite? Tr Interstitial to groundmass minerals. Fibrous Colorless in PPL and with very low birefringence in XPL Pyrite Tr Interstitial. Anhedral to euhedral. Forms concentrations (percolation veins?) within groundmass; a massive vesicle rim; lines some gas vesicles (preceding calcite); one area of mesostasis is 40% pyrite. VESICLES/ CAVITIES PERCENT PERCENT ORIGINAL SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.4 3.6 <=0.5 Clay; calcite. Spherical to irregular Gas vesicles may be lined by a fine (0.03 mm) rim of fibrous phyllosilicate (Fe-saponite) mostly followed by a partial to complete infill of anhedral to subhedral to calcite. Segregation vesicles 2.8 2.8 <=1 Spherical Filled wholly or partially by groundmass material with feathery pyroxene and granular iron oxides; commonly with one or more gas vesicle (see description above). In one case a massive pyrite rim is present (see above). COMMENTS: Bifurcating calcite-filled vein (0.1mm width) with partly detached groundmass fragments. It cross-cuts plagioclase crystals as well as calcite filled vesicles. There is no associated alteration halo around the vein within the groundmass. "168-1027B-61X-CC, 25-28 cm" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: cryptocrystalline to microcrystalline TEXTURE: Intersertal. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr 1 Euhedral-subhedral Contains small spinel inclusions Mafic minerals 0 5 "Euhedral-subhedral, skeletal" Completely replaced by secondary minerals (calcite and clay [Fe-saponite]) GROUNDMASS Plagioclase 32.6 32.6 0.1-0.8 (Ave 0.4) Microlitic laths "Exhibit quench textures (hollow crystals, swallowtails)" Spinel Tr Tr <=0.01 Euhedral Associated or partially enclosed in microlitic plagioclase lath Pyrite Tr Tr <=0.015 Granular In mesostasis and plagioclase. Magnetite Tr Tr <=0.01 Euhedral-subhedral Disseminated in the groundmass Mesostasis 56.8 59.2 Cryptocrystalline to microcrystalline; texture varies throughout section with: i) intersertal texture with plagioclase microlites; ii) patches of comb-texture; iii) feathery pyroxene +/- mt crystals; and iv) faint sheaf-spherical to branching texture. Contains ghost/skeletal mafic minerals and euhedral to sub-euhedral magnetite; some of the mesostasis is replaced by yellowish-to brown clay mineral (fibrous to patchy). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (poss. saponite?) 7.2 Mesostasis. Outer rim of gas vesicles. Patchy to fibrous Colorless to yellowish to light browns; low birefringence. Calcite 1.8 Vesicles; mafic minerals; vein. Anhedral to subhedral; fibrous to platy. "Completely replaces mafic mineral phenocrysts and microlites, as well as infilling the center of segregation vesicles (see below). " VESICLES/ CAVITIES PERCENT PERCENT ORIGINAL SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.8 2.4 <=0.5 calcite +/- saponite or empty Spherical to irregular Gas vesicles may be lined by a fine (0.03 mm) rim of fibrous phyllosilicate (saponite?) which is generally followed by a partial to complete infill of anhedral to subhedral sparry calcite. Segregation vesicles 0.8 0.8 <=0.8 Spherical Filled wholly or partially by groundmass material with feathery pyroxene and granular iron oxides; commonly with one or more gas vesicle (see description above). COMMENTS: "Anastomosing calcite vein (0.1mm width) infilled by calcite crystals (<=0.7mm long and <=0.1mm wide), containing partly detached groundmass fragments. The vein" cross-cuts plagioclase crystals and may be partially lined by a very fine layer of saponite. There is no associated alteration halo around the vein within the groundmass. "168-1027B-62X-CC, 07-10cm" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: cryptocrystalline to microcrystalline TEXTURE: Varied: intersertal; pilotaxitic. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr <=1.6-0.5 Subhedral to euhedral laths. Crystals exhibit a faint preferred parallel orientation across the section. Some crystals have an irregular to embayed shape possibly caused by i) skeletal growth; ii) alteration; and/or iii) partial resorption. Mafic minerals (olivine? + pyroxene?) Tr 1.2 <=0.55 Subhedral to anhedral. "Crystals have been completely to partially replaced by either calcite +/- Fe-saponite. Some crystals exhibit an anhedral calcite replaced core, surrounded by a sub- to euhedral rim of fibrous clay. " "In a zone of highly altered groundmass, remnants of fresh anhedral to subhedral pyroxene crystals (0.3-0.15mm) are recognizable. " GROUNDMASS Plagioclase 30.4 30.4 0.1-0.5 (Ave <=0.3) Sub- to euhedral laths. Skeletal and hollow laths; minor rim resorption (see plagioclase comment above.) Mafic phases (olivine? + pyroxene?) 0 4.8 <=0.1 Sub- to anhedral. All mafic groundmass phases have been replaced by calcite or Fe-saponite. Some skeletal/comb-textures crystals can be identified as pyroxene. Magnetite Tr Tr <=0.01 Euhedral Disseminated throughout the groundmass. Mesostasis 50.6 57.8 "Cryptocrystalline; some of the groundmass is replaced by a yellowish-brown clay mineral (fibrous to patchy), mixed locally with fine fibrous calcite. Texture varies from i) intersertal; ii) pilotaxitic; iii) comb texture; to iv) faint sheaf-spherulitic." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (Fe-saponite?) 7 Mesostasis; mafic minerals; outer rim of vesicles; veinlet. Patchy to fibrous "Colorless to yellow/light brown; low birefringence. Forms a <=0.05mm fibrous rim around some of the spherical and irregular shaped vesicles. On one side of the section, an amorphous brown clay rim (<=0.4-0.15mm thick) partially coats the rock." Calcite 2.4 Vesicles; mafic minerals. Granular to anhedral. "Completely replaces mafic mineral phenocrysts and microlites, as well as infilling the center of vesicles (see below). Calcite in vesicles appears dusty and granular rather than clear and sparry." Pyrite Tr Vein "Granular crystals, <=0.005mm, in saponite vein." Iddingsite Tr Mesostasis. Anhedral Forms irregular dark brown-red blebs in highly altered zone in mesostasis. VESICLES/ CAVITIES PERCENT DISTRIBUTION SIZE (mm) FILLING SHAPE COMMENTS: Vesicles 3.4 Even <=0.5 Clay; calcite. Spherical to irregular "Vesicles are either i) empty; ii) lined by a fine (0.04 mm) rim of fibrous Fe-saponite, or iii) lined by Fe-saponite and then partially to completely infilled by granular to anhedral calcite." COMMENTS: "The degree of alteration varies across the section from slight (<2%) to very high (>80%), producing a patchy texture. In very highly altered zones, the mesostasis is " "replaced by fibrous Fe-saponite. A 0.04mm wide veinlet infilled by fibrous Fe-saponite, cross-cuts the section, cutting through plagioclase crystals and bifurcating " around patches of mesostasis. There is no alteration halo associated with the veinlet. "168-1027B-62X-CC, 39-42 cm" ROCK NAME: Aphyric basalt GRAIN SIZE: Aphanitic: cryptocrystalline to microcrystalline TEXTURE: Pilotaxitic. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase Tr Tr <=1.2 Euhedral-subhedral Lath-shaped crystals exhibit a preferred parallel orientation. Some crystals have a swallowtail structure. Crystals are present singly and within monomineralic and bimineralic clusters. Mafic minerals (olivine? + pyroxene?) 0 3 <=0.8 "Euhedral-subhedral, skeletal" Completely replaced by secondary minerals including clay (Fe-saponite) + calcite. (Original mineralogy based upon euhedral grain shape.) Present as single crystals and in bimineralic clusters with plagioclase. GROUNDMASS Plagioclase 14.8 14.8 <=0.2 (two populations: 0.2 & 0.05) Microphenocrysts; microlitic laths and needles. "Most form perfect euhedral laths, although a few skeletal crystals exist. Crystals occur singly and in stellate groupings." Mafic phases (olivine? + pyroxene?) 0.3 3.5 "Skeletal, subhedral-anhedral" Pseudomorphs of skeletal to anhedral-subhedral crystals (olivine) isolated or intergrown with plagioclase are completely replaced by secondary calcite and clay. A trace amount of fresh microlitic pyroxene also occurs in the groundmass. Spinel Tr Tr <=0.01 Euhedral-subhedral Associated or partially enclosed in microlitic plagioclase laths. Pyrite Tr Tr <=0.01 Granular In mesostasis. Magnetite 1.8 1.8 <=0.01 Euhedral-subhedral Disseminated in the groundmass. Mesostasis 68.8 75.2 Cryptocrystalline; some of the groundmass is replaced by a yellowish-brown clay mineral (fibrous to patchy). SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clays 5 Mesostasis; outer rim of vesicles; interstitial to groundmass phase. Patchy to fibrous; radiating fibrous. "Colorless to yellow/light brown; low birefringence. Two different clay minerals can be identified. The first (Fe-saponite) has a yellow-brown color in PPL, with low birefringence and commonly lines vesicles." "The second clay is very pale to colorless, with a radiating fibrous texture, occurring within the groundmass and as vesicle infills; this may be a non-pleochroic chlorite or a mixed layer phase (chlorite-smectite)." Calcite 1.4 Vesicles; mafic minerals; vein. Fibrous to anhedral. "Completely replaces mafic mineral phenocrysts and microlites, as well as infilling the center of vesicles (see below). Some calcite in vesicles is dusty and granular near the vesicle wall, and clear and sparry inside." VESICLES/ CAVITIES PERCENT DISTRIBUTION SIZE (mm) FILLING SHAPE COMMENTS: Vesicles 1.4 Even <=0.6 Clay; calcite. Spherical to irregular Gas vesicles can be i) lined by a fine (0.03 mm) rim of fibrous phyllosilicate (Fe-saponite); ii) lined by clay followed by a partial to complete infill of fibrous to anhedral calcite; ii) completely infilled by fibrous saponite. COMMENTS: The groundmass is represented by patches of dark cryptocrystalline to lighter microcrystalline (pilotaxitic) material. A discontinuous band of coarser-grained material "may represent a magmatic fracture or vein, filled with non-aligned crystals (which may have cooled slowly). In addition, a second (0.04mm) fracture crossing the section " "which is infilled by fibrous clay, appears to be associated with a zone of dusty alteration within the mesostasis." "168-1027C-01R-01 (piece 1A, 10-16cm)" ROCK NAME: Diabase GRAIN SIZE: Phaneritic; holocrystalline; fine to medium grained TEXTURE: Diabasic; ophitic to subophitic; intergranular PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS Olivine 2.4 14.6 <=0.6 (Ave 0.4) Rounded - anhedral Partially (outer rim) to completely replaced by olive brown clay (Fe-saponite?) Plagioclase 50.4 50.4 0.2-1.6 (Ave 0.8) Subhedral-euhedral laths Normal zoning; seriate texture. Clinopyroxene 21.8 21.8 0.15-2 (Ave 0.5;1) Subhedral - anhedral Fresh; subophitic to ophitic; contains minor opaque inclusions. Opaque 3.2 3.2 0.02-0.4 (Ave 0.07-0.1) Anhedral-skeletal Occurs primarily in olivine and at grain boundaries of all silicate phases. Includes Fe-oxide and trace sulfide. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 18 Vesicles; vein; interstitial olivine Pale brown to olive brown saponite (Fe?); fibrous to granular cryptocrystalline texture. Carbonate 4 Vein Anhedral to fibrous aggregates; both calcite and aragonite are present. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Vesicles 0.2 Even. 0.6-0.7 Clay Round Fibrous to cryptocrystalline granular brown saponite infills vesicles (fibrous at rim to granular in core). COMMENTS: "A vein (<=2mm wide) anastomoses across the section. The infill is uneven, with a patchy to intermingled mixture of granular carbonate to fibrous " saponite. Associated with the vein is an uneven 0.2-0.8mm alteration halo (saponite rich). "168-1027C-03R-02 (piece 5, 125-126cm)" ROCK NAME: Moderately phyric plagioclase-olivine-pyroxene basalt GRAIN SIZE: Aphanitic; cryptocrystalline to microcrystalline TEXTURE: Varitextured; glomeroporphyritic; intersertal; sheaf-spherulitic; vesicular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 3.6 0.2-0.8 (Ave 1.3) Euhedral Solitary or intergrown with plagioclase laths; completely replaced by celadonite and/or saponite. Plagioclase 5.8 5.8 1-2.4 Euhedral Stubby zoned laths as well as more slender laths. Mostly glomerocrysts either monomineralic (pl alone) or polymineralic (pl+cpx). Clinopyroxene 1.6 1.6 0.4-0.6 (Ave 0.5) Anhedral-subhedral Intergrown with slender plagioclase laths; some bowtie structures. GROUNDMASS Plagioclase 14 14 0.1-0.5 Subhedral "Microcrysts of plagioclase (0.1-0.4mm) as well as microlites (0.2-0.05mm; average <=0.1mm). Hollow, swallowtail and skeletal forms abound." Olivine 7.4 7.4 <=0.1 Subhedral to granular "Microcrystalline to feathery, dendritic crystals, intergrown with opaques." Opaques 1.5 1.5 Ave 0.02 "Granular, elongate, skeletal" Intergrown with pyroxene and mesostasis. Pyrite/pyrrhotite Tr Tr <=0.008 Spherical bleb In plagioclase crystal; lamellar intergrowth. Pyrite Tr Tr <=0.01 Granular In mesostasis. Mesostasis 65.1 65.1 Forms patches with sheaf spherulitic to sub-plumose texture. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Celadonite 4 Olivine; vesicles; mesostasis "Bright green, replacing rims to cores of olivine and filling vesicles; fibrous to granular cryptocrystalline texture." Saponite 0.6 Olivine; vesicles "Tan brown saponite replacing cores of olivine, and infilling vesicles." Carbonate Tr Olivine Replaces the cores of some olivines. Pyrite Tr "Olivine, vesicles" "Occurs as granules <=0.005mm in saponite-celadonite pseudomorph of olivine, and as granules <=0.001mm within celadonite vesicle fillings." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 1 Even <=0.5 Clay Round Filled by bright green celadonite and brown saponite layers (see comments below). Segregation vesicles 0.2 Even <=0.6 Mesostasis Round "Filled by cpx+opaques microcrystalline mesostasis, with incipient bright green celadonite alteration." COMMENTS: "Vesicles fills are simple (bright green celadonite) to complex (bands of bright green celadonite, blue green clay, tan saponite +/- opaques). Most " commonly have green clays followed by tan clay at core. Within the mesostasis there are altered patches dominated by either celadonite or a mixture of celadonite + saponite. "168-1027C-04R-01 (piece 11, 63-67 cm)" ROCK NAME: Moderately to highly phyric plagioclase-olivine-pyroxene basalt GRAIN SIZE: Aphanitic; cryptocrystalline to microcrystalline. TEXTURE: Varitextured; glomeroporphyritic; intersertal to intergranular; sheaf-spherulitic; vesicular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 2.8 0.1-0.7 (Ave 0.4) Euhedral Solitary or intergrown with plagioclase; phenocrysts and microphenocrysts present; completely replaced by celadonite +/- saponite. Plagioclase 5.8 5.8 0.4-1.6 (Ave 0.8) Sub-euhedral Large stubby laths form phenocrysts (<=1.6mm); more slender laths vary from 0.4-1.0mm and form microphenocrysts. Clinopyroxene 1.4 1.4 0.2-1.2 (Ave 0.3) An-euhedral "One 1.2mm euhedral phenocryst, plus numerous 0.2-0.5mm anhedral microphenocrysts, intergrown with plagioclase." GROUNDMASS Plagioclase 14.8 14.8 <0.5 Thin microlaths "Microlites and skeletal, hollow crystals; no preferred alignment." Clinopyroxene 8.6 8.6 0.02-0.05 (Ave 0.04) Anhedral; sheaves Small round crystals plus very fine fibrous grains; intersertal to sheaf-spherulitic between plagioclase laths. Opaques 1.6 1.6 <=0.01 Granular; dendritic Occurs disseminated throughout the mesostasis. Mesostasis 55.8 63.8 Consists of sheaf spherulitic cryptocrystalline material + fibrous cpx(?) + opaques; partially altered to brown saponite +/- green celadonite. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Celadonite 6.4 Vesicles; olivine; mesostasis; vein Bright green color; fibrous texture. Saponite 3.8 Vesicles; olivine; mesostasis; vein Light brown to tan color; granular cryptocrystalline texture. Iddingsite 1.8 Vesicles; olivine; mesostasis; vein Includes some highly reflective hematite. Carbonate Tr Olivine Precedes celadonite at the rim of one vesicle. Pyrite Tr Vesicles Irregular pyrite-magnetite intergrowth (0.01mm) attached to a celadonite patch; globular pyrite (0.02mm) attached to a vesicle wall and covered by celadonite fill. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.6 Even <=0.5 Clays Round Primarily occur within segregation vesicles; some occur within the mesostasis. Infilled by celadonite +/- saponite +/- iddingsite +/- pyrite (see comments below). Segregation vesicles 0.6 Even <=0.6 Mesostasis Round Filled by cpx+opaque+plag rich mesostasis +/- celadonite clay. COMMENTS: "Section cross cut by a 0.08-0.01mm wide vein, infilled locally by iddingsite, celadonite and saponite; everything is stained orange. Iddingsite is generally" "along the margins of the vein, whilst clay fills the interior. Vesicle fill chronology: minor pyrite, followed by isopachous celadonite, orange-stained" green clay (also celadonite); celadonite followed by iddingsite; saponite (brown-orange) followed by celadonite; green-orange saponite followed by "iddingsite, brown saponite and celadonite." "168-1027C-04R-01 (piece 17, 110-113 cm)" ROCK NAME: Sparsely to moderately phyric plagioclase-pyroxene-olivine basalt. GRAIN SIZE: Aphanitic; hypocrystalline. TEXTURE: Intersertal to intergranular; seriate. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 1 0.2-0.7 (Ave 0.6) Euhedral Replaced by bright green/yellow celadonite at rim and deep brown-red iddingsite in core. Plagioclase 1.6 1.6 0.6-1.2 (Ave 0.8) Sub-euhedral laths Laths plus skeletal forms; solitary crystals and in glomeroporphyritic clusters with pyroxene (some bowtie structures); variable alteration. Clinopyroxene 1 1 0.2-0.6 (Ave 0.4) Euhedral-subhedral "Fresh; occurs as solitary crystals and in glomeroporphyritic clusters with plagioclase, or subophitic arrangements." GROUNDMASS Plagioclase 42 42 0.1-0.2 Euhedral-subhedral Laths plus quench crystals. Olivine 0 3 0.1-0.2 Sub-euhedral Completely replaced by colorless to pale green clay (saponite +/- celadonite). Clinopyroxene 24 24 0.05-0.12 (Ave 0.7) Subhedral Crystals become more euhedral and larger in unaltered areas of mesostasis. Opaques 4.8 4.8 0.02-0.08 (Ave 0.04) Granular; anhedral Forms euhedral cubes as well as anhedral needles and laths; disseminated throughout the mesostasis. Pyrite Tr Tr <=0.01 Granular In plagioclase. Mesostasis 13.8 21 Varies from brown glass to cryptocrystalline material; altered to brown clay (saponite) in alteration halo. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: "Clay (celadonite, saponite, iddingsite)" 4 Olivine Bright green celadonite rims to replaces olivine. After rim often find deep brown-red iddingsite. Microlites of olivine replaced by pale green clay (saponite?). "Clay (celadonite, saponite, iddingsite)" 1.6 Vesicles "Either completely filled by bright green celadonite +/- saponite, or rimmed by celadonite followed by brown saponite +/- brown-red iddingsite." "Clay (celadonite, saponite, iddingsite)" 6.4 Mesostasis Brown saponite +/- green celadonite replaces mesostasis in alteration halo. Hematite 0.8 Olivine; vesicles "Forms the red ""oxide"" core in some vesicles, after a rim of celadonite. Also occurs within olivines which have been altered to celadonite." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 1.6 Even 0.2-0.8 Clays; empty Round "Only filled in the alteration halo by green celadonite +/- brown saponite. In the fresh rock, the vesicles can have a patchy <=0.05mm pale green saponite(?) rim." COMMENTS: The type of clay is controlled by the location of the alteration halo. The margin of the rock has a 0.8-1.2mm band in which the mesostasis + olivine is replaced by orange-brown-red clays with a granular to fibrous texture. This grades into a <=2.5mm band with lime green celadonite alteration clays + brown-red iddingsite + hematite. Vesicles can be rimmed by green to brown saponite +/- brown-red iddingsite or just green fibrous clay. The mesostasis in the next 6mm band of rock is altered to brown clay (saponite). There is a sharp boundary between the alteration halo and fresh rock. "168-1027C-04R-01 (piece 20, 131-136 cm)" ROCK NAME: Moderately phyric plagioclase-pyroxene-olivine basalt. GRAIN SIZE: Aphanitic. TEXTURE: Varitextured; glomeroporphyritic; intersertal to intergranular; sheaf spherulitic; vesicular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 2.2 0.25-1 (Ave 0.6) Sub-euhedral Completely replaced by olive brown-green clay. Plagioclase 5 5 3-Jan Euhedral laths "Laths and stubby crystals; coarse laths are zoned; glomeroporphyritic and solitary crystals; smaller phenocrysts are typically subhedral, elongate laths." Clinopyroxene 3 3 1-2 (Ave 1.6) Euhedral "Included plagioclase microlites embedded in the rim, as well as a common mesostasis embayment." GROUNDMASS Plagioclase 30 30 <=1 (Ave 0.6) Subhedral Subhedral elongate laths intergrown with pyroxene; skeletal forms also present. Olivine 0 2.8 <=0.25 Subhedral Completely replaced by clays (see above). Clinopyroxene 28.2 28.2 <=0.4 An-subhedral "Granular microphenocrysts, intergrown with plagioclase." Opaques 3.8 3.8 <=0.1 Skeletal Elongate skeletal crystals. Pyrite Tr Tr <=0.03 Granular In plagioclase (<=0.015mm); interstitial. Mesostasis 24.8 24.8 Patches of fined grained pyroxene(?) + opaques+clay throughout section. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 5 Olivine; vesicles; mesostasis "Olive green, non-pleochroic." Calcite Tr Olivine Trace amounts replace the cores of some olivines. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.2 Even <=0.5 Clay Round Occur in mesostasis and within segregation vesicles. Segregation vesicles Tr Even <=0.6 Mesostasis Round Infilled by microcrystalline pyroxene (<=0.02mm) + opaque oxides (<=0.35mm) + plagioclase (<=0.04mm). COMMENTS: "This varitextured rock is dominantly intergranular, although portions are intersertal, plumose and sheaf-spherulitic." 1-5mm plagioclase-pyroxene glomerocrysts occur. One large pyroxene phenocryst contains a 25 micron glass inclusion with multiple vapor bubbles. "168-1027C-04R-02 (piece 2, 09-15 cm)" ROCK NAME: Moderately phyric plagioclase-olivine-clinopyroxene basalt. GRAIN SIZE: "Aphanitic, cryptocrystalline to microcrystalline." TEXTURE: "Varitextured: intergranular to intersertal, poikilitic, vesicular." PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 2.2 0.1-1.0 (Ave 0.4) Sub-euhedral Completely replaced by pale brown granular Mg-saponite; some in poikilitic arrangement with plagioclase. Plagioclase 4.2 4.2 <=1.4 (Ave 0.6) Sub-euhedral Stubby and slender laths. Clinopyroxene 1.6 1.6 0.2-0.6 (Ave 0.3) Sub-anhedral Fresh; normally subophitic with respect to plagioclase. GROUNDMASS Plagioclase 31.8 31.8 <=0.2 "Laths, needles" Stellate arrangements; hollow crystals abound. Olivine 0 0.8 <=0.01 Clinopyroxene 36.2 36.2 <=0.15 (Ave 0.1) Anhedral Normally associated with plagioclase microlites in crystal clusters. Opaques 5.2 5.2 0.01-0.05 Euhedral-skeletal Located within mesostasis or within or at rims of olivine phenocrysts. Pyrite Tr Tr <=0.01 Granular In plagioclase groundmass grains. Mesostasis 14.8 17.2 "Cryptocrystalline pyroxene and opaques, distributed heterogeneously." SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 5.4 Vesicles; olivine; mesostasis Granular. Carbonate 0.2 Occurs as euhedral rhombs(?) along some vesicle walls; the vesicles were subsequently filled by clay. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.6 Even <=0.5 Clay Round Infilled by amorphous Mg-saponite or empty. Segregation vesicles Tr Even <=0.5 Mesostasis Round Infilled by mesostasis with saponite-filled gas vesicle in center in most cases. COMMENTS: "168-1027C-05R-01 (piece 2, 06-10 cm)" ROCK NAME: Moderately phyric plagioclase-olivine basalt. GRAIN SIZE: Aphanitic. TEXTURE: "Subvariolitic, glomeroporphyritic, vesicular." PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 2.4 0.2-0.9 Euhedral Completely replaced by fibrous-granular clay. Plagioclase 3 3 0.8-2.0 Euhedral Simple and oscillatory zoning. GROUNDMASS Plagioclase 3.8 3.8 <=0.5 Laths "Swallowtail, hollow forms common." Olivine 0 0.4 <=0.2 Euhedral Completely replaced by clay. Clinopyroxene 2.2 2.2 <=0.1-0.5 Euhedral-anhedral Solitary euhedral microphenocrysts; anhedral glomerophyric clots intergrown with plagioclase and olivine. Pyrite Tr Tr <=0.005 Granular In mesostasis. Opaques Tr Tr <=0.005 In mesostasis at margins of cryptocrystalline sheafs. Mesostasis 87.4 87.4 Sheaf-like varioles of fibrous pyroxene(?) and dusty opaques. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 2.8 "Olivine, vesicles, vein" Vesicle fills comprise a lining of fibrous clay followed by spherulitic clay filling. Celadonite Tr Vesicles Restricted to one corner of the thin section. Iddingsite/FeO(OH) Tr "Olivine, vesicles, vein" Associated with the limited celadonite alteration. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.8 Even 0.1-0.4 Clay Round Filled by fibrous bands (<=0.02mm) or saponite. Cavities <=0.3 Clay Irregular <=0.02mm saponite band rims cavities; then infilled by radiating fibers of saponite. COMMENTS: "Several branching veinlets, <=0.03mm wide, with saponite +/- iddingsite/FeO(OH)." "168-1027C-05R-01 (piece 8, 92-96 cm)" ROCK NAME: Moderately phyric plagioclase-olivine basalt. GRAIN SIZE: Aphanitic. TEXTURE: "Glomeroporphyritic, intersertal, vesicular." PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 1.2 <=1.0 Euhedral Completely replaced by clay (saponite); forms glomeroporphyritic clusters with plagioclase as well as solitary crystals. Plagioclase 3 3 0.5-2.8 (Ave 0.8) Euhedral-subhedral laths Euhedral laths and stubby crystals. Some crystals exhibit resorption along the rims +/- in the core. Strong oscillatory zoning is common. Inclusions of glass and spinel occur in the cores of some crystals. Spinel Tr Tr <=0.06 Euhedral Occurs within plagioclase phenocrysts; deep red color. GROUNDMASS Plagioclase 15.2 16.2 0.1-0.3 (Ave 0.15) Euhedral; microlites "Occurs as solitary microlites and microlaths, as well as forming an intersertal network. Quench crystals are abundant." Olivine 0 2.8 0.1-0.3 Euhedral Completely replaced by fibrous saponite. Clinopyroxene 6.4 6.4 <=0.1 (Ave 0.05) Granular; subhedral-anhedral Forms granular grains within the groundmass or attached to plagioclase microlites. Also present as very fine microlites (feathery to rodlike texture) in the mesostasis. Opaques 1 1 <=0.005 Skeletal-euhedral Disseminated throughout the mesostasis. Mesostasis 51 68.6 Microcrystalline to cryptocrystalline; varitextured from plumose to comb to sheaf-spherulitic consisting of brown amorphous matter + feathery cpx(?) + opaques. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 20.6 Vesicles; mesostasis; mafic minerals; plagioclase "Fibrous and granular varieties; fibrous saponite commonly forms at the edges of vesicles and minerals, whilst the granular variety is restricted to the cores." Celadonite 1.6 Vesicles; mesostasis Fibrous; present as either pure celadonite or in a celadonite-saponite mixture. Iddingsite/FeO(OH) 1.2 Mesostasis "Occurs in the center of irregular alteration patches within the mesostasis, following celadonite and saponite." Pyrite Tr "25-50µm euhedral to subhedral grains, associated with celadonite +/- saponite alteration." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.8 Even <=0.5 Clay Round Completely infilled by clays (saponite + celadonite) COMMENTS: "Numerous 1-2cm patches of intense clay alteration where the groundmass is completely replaced by saponite +/- celadonitic clays, with vestiges of plagioclase " microlites (+/-unaltered mesostasis) included. A few 0.4-1mm alteration patches consist primarily of celadonitic clay (either pure celadonite or a mixed "celadonite-saponite clay). Within these patches, iddingsite/Fe(OH) staining and growth occurs. In addition, relatively coarse pyrite grains may be found" "associated with these patches. The clay + pyrite generally occur in the outer layers of the alteration patches, whereas iddingsite occurs within the center" (oxidation gradient?). "168-1027C-05R-02 (piece 1A, 01-09 cm)" ROCK NAME: Moderately phyric plagioclase-olivine basalt. GRAIN SIZE: Cryptocrystalline. TEXTURE: "Varitextured (glassy, variolitic, subvariolitic, spherulitic, intersertal)" PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0.8 1 0.3-1.0 Euhedral to subhedral Single microphenocrysts are fresh in the glass rim and completely altered to clay +/- talc in the crystalline rock. Plagioclase 2 2 1.0-1.5 Euhedral to subhedral "Equant to lath-shaped, mostly single phenocrysts." GROUNDMASS Plagioclase 7.8 7.8 <=0.5 Skeletal laths Microlites. Olivine/ clinopyroxene 0 2.6 <=0.3 Pseudomorph/ subhedral Completely replaced by clay +/- talc Spinel Tr Tr 0.1 Subhedral Mesostasis 68.6 71.5 Glass 14.1 14.1 "Fresh, transparent, pale brown. Contain few spherulites, grades to the variolitic zone." Pyrite/pyrrhotite Tr Tr 0.03 "Rounded, lamellar intergrowth" "Spherical bleb in glass, lamellar intergrowth." Pyrite Tr Tr <=0.05 Granular In mesostasis. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Clay (saponite?) 6.7 "Olivine, mesostasis, vesicles, vein" Fibrous to cryptocrystalline grain "Yellow to colorless to pale brown. 2.2% after mafic mineral, 1.2% pseudomorph after olivine, 2.2% in vein, 1.1% as alteration of mesostasis (total 6.7%)" Talc Tr Olivine Fibrous Pale yellow to colorless Zeolites Tr Veinlets Fibrous Colorless Pyrite Tr Glass Irregular bleb Altered glass halo around the zeolite vein Carbonate Tr Vein <=0.05 Fibrous Fibrous vein (0.4mm wide) with 0.02mm saponite selvages VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles Tr <=0.3 Clay Round Completely filled COMMENTS: "Quench margin with complete gradation from fresh glass (7mm) to variolitic (1-2mm), subvariolitic (3-4mm) and spherulitic zone" "(honey comb, plumose, sheaf spherical and branching textures)" "168-1027C-05R-02 (piece 2, 49-51 cm)" ROCK NAME: Moderately phyric plagioclase-pyroxene-olivine basalt. GRAIN SIZE: Cryptocrystalline TEXTURE: Varitextured: intersertal to intergranular PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine Tr 1 0.5-1.2 Euhedral to subhedral Almost completely replaced by clay or fibrous talc Plagioclase 3.2 3.2 0.8-2.4 Laths Normal and oscillatory zoning Clinopyroxene 0.4 0.4 1.0-2.4 Subhedral Polymineralic glomerocrysts with plagioclase; contain devitrified glass inclusion GROUNDMASS Plagioclase 15.2 15.2 <=0.5 Laths Skeletal crystal are common Olivine 0.8 1 <=0.3 Euhedral Variable from fresh to completely altered Clinopyroxene 2.3 2.3 <=0.3 Anhedral Intergrowth with plagioclase lath Opaques 1 1 <=0.05 Skeletal grains Pyrite Tr Tr <=0.015 Granular In mesostasis Mesostasis 67.1 74.4 Sheaf-spherulitic SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 3.8 "Vesicles, olivine, vein, mesostasis" "Pale brown, cryptocrystalline to fibrous aggregates " Celadonite 4.8 "Vesicles, vein, mesostasis" "Bright green, cryptocrystalline to fibrous aggregates " Iddingsite 0.4 "Vesicles, vein" Bright orange to red Carbonate Tr "Vesicles, mesostasis" Pyrite Tr 0.01mm grains associated with saponite VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas/segregation vesicles 0.8 <=0.6 "Iddingsite, celadonite, saponite" Complex filling are common COMMENTS: "Vein (0.05-0.1mm wide) consists of green celadonite margin and pale saponite interior, with some iddingsite-FeO(OH) patches" Significant groundmass replacement in millimetric patches (saponite+celadonite) "168-1027C-05R-03 (piece 8, 105-109 cm)" ROCK NAME: Moderately phyric plagioclase basalt. GRAIN SIZE: Cryptocrystalline TEXTURE: "Varitextured (glassy, variolitic, subvariolitic, spherulitic, intersertal)" PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Plagioclase 3.6 3.6 0.5-1.3 "Subhedral, lath" "Single megacryst (lath 8x1.4 mm) with labyrinthine amoeboid, devitrified glass inclusion" Spinel Tr Tr 0.2 Euhedral GROUNDMASS Plagioclase 15.4 15.4 0.1-0.5 "Lath, skeletal" Local pilotaxitic Olivine 0.4 3 <=0.6 Euhedral Occur singly and in clots with plagioclase. Usually altered; some fresh crystal in glass margin Clinopyroxene Tr Tr <=0.001 Anhedral Intergrown with plagioclase Pyrite Tr Tr <=0.4 Rounded In mesostasis Glass 0.3 Pale brown; fresh Mesostasis 76.7 77.5 "Variolitic, subvariolitic, honey comb, plumose, sheaf spherical, branching texture" SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 3.6 "Vesicles, vein, olivine, mesostasis" "Pale brown, fibrous to cryptocrystalline aggregates" Carbonate Tr Olivine VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.2 0.1-0.25 Clay Rounded Segregation vesicles 0.2-0.4 clay+ mesostasis Ovoid COMMENTS: Vein (0.01-0.02 mm wide) filled by fibrous saponite "168-1027C-05R-04 (piece 5, 68-70 cm)" ROCK NAME: Sparsely phyric plagioclase-olivine basalt. GRAIN SIZE: "Aphanitic, cryptocrystalline to microcrystalline." TEXTURE: Intersertal to intergranular. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 1.6 0.8-2.8 Euhedral Replaced by saponite +/- talc +/- carbonate. Millerite (?) inclusion. Plagioclase 1 1 0.6-2.0 Laths "Both stubby and slender, normally zoned." Spinel Tr Tr <=0.2 Euhedral Enclosed or attached to olivine and plagioclase; may contain glass inclusions with bubbles. GROUNDMASS Plagioclase 22.8 22.8 <=0.5 "Euhedral lath, subhedral" Slender; quench forms abound. Olivine 0 2.4 <=0.3-0.1 (Ave 0.2) Anhedral to euhedral Partially to completely replaced by saponite +/- talc +/- carbonate. Remnant olivine frequently left in core. Clinopyroxene 2.8 2.8 <=0.3 Anhedral Granular interstitial to plagioclase. Microcrystalline fibrous sheafs of cpx. Pyrite Tr <=0.01 Anhedral Granular crystals in mesostasis. Mesostasis 61.2 69 Sheaf-spherical texture. Microcrystalline cpx fibers and opaques. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 11 "Olivine, vesicle" Granular. Carbonate 0.4 "Olivine, vesicle" Fibrous to partially infill. Talc 0.6 Olivine Pseudomorph after olivine. Millerite (?) Tr Olivine Acicular sulfide fibers and laths in olivine pseudomorphs. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles 0.4 <=0.4 Saponite +/- carbonate filled Round Segregation vesicles Tr <=0.5 Groundmass Round Infilled by mesostasis and microcrystalline cpx fibers + opaques. Some contain inner fill of granular saponite. COMMENTS: "168-1027C-05R-05 (piece 3, 32-43 cm)" ROCK NAME: Moderately phyric plagioclase-olivine basalt. GRAIN SIZE: "Aphanitic, microcrystalline to cryptocrystalline." TEXTURE: Intersertal to intergranular with locally sheaf-spherulitic patches. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 0 1 0.7-1.2 Euhedral to subhedral "Fresh to pseudomorph (replaced by talc, iddingsite, saponite)." Plagioclase 2.2 2.2 0.5-2.2 Euhedral Single crystals to glomerocrysts. Two grain size populations: 2mm and 0.5-0.8mm. GROUNDMASS Plagioclase 42.2 42.2 <=0.2-0.5 Euhedral lath to platy. Arrange randomly or in stellate form. Olivine/Pyroxene 31.5 32.5 <=0.2 Subhedral to anhedral Olivine? replaced by clays and iddingsite. Skeletal and fresh pyroxene crystals (sheaf-spherical). Opaques Tr <=0.05 Euhedral-anhedral and skeletal Individual grains occurs singly or in pods Mesostasis 18.3 21 Cryptocrystalline and also skeletal sheafs of fibrous crystals. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Celadonite 0.8 "Vesicles, veins, groundmass" "Bright green, fibrous to granular in vesicle and veins. Occurs as mixture with saponite. Fills vesicles completely or just core." Saponite 1.2 "Vesicles, veins, groundmass" Yellow to pale brown. Fills whole vesicles. Carbonate Tr "Vesicles, mafic phenocrysts" Fibrous in veins. Cross-fibers texture. Iddingsite 3.8 "Vesicles, veins, groundmass (olivine)" Red-brown rims (<=0.05mm) around olivine and some vesicles. Fills completely other vesicles. Talc Tr Olivine Replaces the core of some olivine crystals and forms isolated grains in saponite-replaced olivine pseudomorph. VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles Tr 0.4-0.15 Clays Round-ovoid "Mono or polymineralic infills including iddingsite, celadonite, olive brown, orange and pale brown saponite." Segregation vesicles Tr <=0.45 "Mesostasis, clays" Round Mesostasis infills vesicle with celadonite or saponite. COMMENTS: "Sample is cut by a 0.5mm-wide vein filled by celadonite (green), saponite (yellow), iddingsite, carbonate. Smaller bifurcating and" anastomosing (<=0.1mm) fractures diverges off main vein and partially line/to fill by layers of saponite +/- iddingsite +/- celadonite. "168-1027C-05R-05 (piece 11, 121-123 cm)" ROCK NAME: Sparsely to moderately phyric plagioclase-olivine basalt. GRAIN SIZE: "Aphanitic, microcrystalline to cryptocrystalline." TEXTURE: Intersertal to intergranular with locally sheaf-spherulitic patches. PRIMARY MINERALOGY PERCENT PRESENT PERCENT ORIGINAL SIZE (mm) COMPOSITION MORPHOLOGY COMMENTS PHENOCRYSTS Olivine 1 1 0.6-1.6 (Ave 1.0) Euhedral to anhedral Fresh to variably altered crystals; replaced to pseudomorph by clay and carbonate. Plagioclase 1.2 1.2 0.8-2.0 (Ave 1-2) Euhedral to subhedral Laths and stubby sections; simple to oscillatory zoning; crystals has core full of amoeboid glass inclusions. Spinel Tr Tr 0.05 Euhedral Single inclusion in plagioclase phenocryst. GROUNDMASS Plagioclase 18 18 0.5-0.1 (Ave 0.2) Euhedral Microlaths and microlites; numerous quenched crystals. Olivine 0 0.8 0.1-0.2 (Ave 0.15) Euhedral to subhedral Fresh to variably replaced by red-brown iddingsite and brown saponite and carbonate. Clinopyroxene 1 1 <=0.1 Sub/anhedral and fibrous Occurs as small grains interstitial to plagioclase and as microcrystalline fibrous sheafs in mesostasis. Mesostasis 74.6 78 "Cryptocrystalline to microcrystalline sheaf-spherical texture, intersertal." Pyrite Tr Tr <=0.025 Anhedral Granular disseminated crystals in mesostasis. Opaques Tr Tr <=0.04 Anhedral to skeletal Disseminated throughout mesostasis at margins of micro- to cryptocrystalline bundles. SECONDARY MINERALOGY PERCENT REPLACING/ FILLING COMMENTS: Saponite 3.2 "Olivine, vesicles" Granular pale brown. Celadonite 0.4 Vesicles Fibrous bright green. Carbonate Tr "Olivine, vesicles" Sparry aragonite (2V~20¡) after olivine. Iddingsite 0.6 "Olivine, vesicles, vein, groundmass" "Brown-red, fibrous-granular; sometimes intermixed with celadonite." VESICLES/ CAVITIES PERCENT LOCATION SIZE (mm) FILLING SHAPE COMMENTS: Gas vesicles Tr Even 0.3-0.05 Clay "Round, irregular" "Some are empty. Variable infill either monomineralic or polymineralic in bands. Includes pale brown saponite, fibrous celadonite, opaques. " Segregation vesicles Tr Even <=0.2 Mesostasis and clay Round "Infilled partially by opaque-rich mesostasis and inner core filled by rim of saponite, iddingsite followed by core of carbonate." COMMENTS: "Groundmass is variably altered by saponite, iddingsite +/- celadonite. Some vein (<=0.02mm) crosscuts section. Vein is anastomosing and bifurcates at points." It is infilled by iddingsite with mixed celadonite in patches. Associated with celadonite + iddingsite zones is a <=0.02mm alteration halo. "Groundmass proximal to iddingsite vein is altered by iddingsite, elsewhere saponite is the dominant alteration phase."