G104 0642E005R03061063008 0001 LEH Sparsely olivine plagioclase phyric basalt Flow unit 1 Olivine 3-5 3-5 .1-.4 Euhedral Completely altered to iddingsite. Opaques Plagioclase/Cpx 2-3 85-90 2-3 85-90 < 0.1 N/A Fe3O4 Skeletal N/A Completely altered to clays and carbonate. Vesicles ~5 Round Sometimes difficult to discriminate from altered groundmass. Clays/carbonate 85-90 Plagioclase, clinopyroxene Groundmass virtually completely altered. Altered. N G104 0642E007R01036038008 0002 LEH Sparsley plagioclase phyric basalt Intersertal Flow 2 Plagioclase < 1 < 1 1.5 Prismatic Altered to clays. Plagioclase Olivine Oxides 30 3 N/A 30 3 N/A 0.05-<0.5 0.1-0.2 0.05-0.5 Laths Euhedral Subhedral Altered to clays. Altered to iddingsite. Vesicles 0 1-2 Clays Smectite-illmenite Clay 40-45< 1 45-50 Plagioclase, vesicle rims Inner vesicles Matrix Interstitial, slightly pleoch., relatively high birefringence. Slightly greenish. Brown to opaque, slightly greenish. Radial, fibrous (quenched textures?) in matrix. N G104 0642E011R02055057002A0004 LEH Sparsely clinopyroxene plagioclase phyric basalt Intersertal Flow 4 Plagiocalse Clinopyroxene < 1 ~1 < 1 ~1 0.4 0.4-0.5 Prismatic Subhedral Wavy extinction. Plagioclase Clinopyroxene Olivine Opaques 35-4020-25< 1 2-3 35-4020-25< 1 2-3 0.3 < 0.05 0.05-0.1 0.05-0.07 Fe3O4 Laths N/A Euhedral Skeletal Completely iddingsitized. vesicles 0 Clays 20 Interstices Brownish green N G104 0642E013R01091095013B0007 LEH Moderately plagioclase phyric basalt Intersertal Flow 7 Plagioclase ~10 ~10 0.5-2.0 Prismatic Agglomerated, fractured and filled with smectite. Plagioclase Clinopyroxene Olivine(?) Opaques ~50 ~20 < 1 ~5 ~50 ~20 < 1 ~5 < 0.1 0.05-0.1 N/A < 0.05 Laths N/A Euhedral Subhedral Hourglass extinction. Altered to iddingsite. Some alteration to iron oxyhydroxides. Vesicles 1-2 0.5-1.0 Smectite Round to subrounded Clays Fe-Ti hydroxides? 10-12~1 In smectite lined vesicles Yellowish green in interstices and possibly small percent replacing olivine. Also around opaques. N G104 0642E014R01038043007 0007 LEH Highly plagioclase phyric basalt Intersertal Flow 7 Plagioclase 12-15 12-15 0.5-2.0 Prismatic Glomerophyric; some cored with previous plagioclase generation and clinopyroxene. Plagioclase Clinopyroxene Opaques 35 20 2-3 35 20 2-3 0.05-0.13 < 0.1 N/A Fe3O4 Laths Subhedral Subhedral Very pale colors, partially altered. Vesicles < 1 Clays 20-25 Interstices Replaces groundmass, cracks in phenocrysts. Several radial aggregates of plagioclase laths, at least one with olivine (iddingsite) at center. N G104 0642E014R01128130019 0008 LEH Highly plagioclase phyric basalt Intersertal, aphanitic Flow 8 Plagioclase 10-12 10-12 0.5-2.0 Prismatic, skeletal Partially altered, zoned, glomerophyric; some with clinopyroxene cores. Plagioclase Clinopyroxene Olivine Opaques 25 20 < 1 3-5 25 20 < 1 3-5 0.1-0.2 0.1-0.15 0.1-0.2 N/A Magnetite Laths N/A Euhedral to subhedral Subhedral Completely iddingsitized. Vesicles N/A 0.2-5.0 Calcite/smectite Round Clays 25-30 Interstices, all minerals Medium green smectite. N G104 0642E015R02073076009 0010 LEH Aphyric basalt Subophitic, aphyric Flow 10 Plagioclase Clinopyroxene Olivine Opaques 35 35 10-125 35 35 10-125 0.4-0.5 0.1-0.3 0.1-0.3 N/A Lathes Euhedral, subhedral Euhedral to subhedral Embayed Size measured along length. Two varities: 1) pale green, incipient alteration. 2) Very pale green;2V ~40 degrees. Rims iddingsitized, remainder altered to clays. Rims coated with altered Fe-Ti OH. Vesicles 4-5 Rimmed with smectite Ovoid Precent of rock estimated separate from rims. Clays 15 Interstitial Olivine tholeiite. Thin section nearly completely destroyed during polisihing; olivine "crystals" (relict) especially affected. N G104 0642E015R04103106007 0011 LUV Sparsely plagioclase phyric basalt Subophitic to intergranular Flow 11 Plagioclase 1-2 1-2 1.5 An60 Short laths, stubby Euhedral, embayed zoned, multiple zones up to An80. Olivine Plagioclase Clinopyroxene Magnetite 5 30 20 2 5 30 20 2 0.15 0.3 0.15 0.1 Equant, subhedral Subhedral, laths Anhedral Subhedral to skeletal Completely altered to iddinsite. Vesicles 0 Clays Clays 10 30 Intergranular Intergranular Green-brown radiating fibers. Amorphous, green-brown. 30% of the slide is plucked. Probably piece number 7. N G104 0642E015R05009012001 0013 LUV Sparsely plagioclase phyric basalt Subophitic, intergranular Flow 13 Plagioclase 1-2 1-2 1-1.5 An54 N/A Plagioclase Clinopyroxene Olivine Magnetite 45 30 10 4 45 30 10 4 0.2-0.4 0.15-0.6 ~0.2 N/A An50 Thin laths N/A Equant N/A Altered to iddingsite to smectite. Intergranular to plagioclase. Vesicles 0 Clays 10 Intergranular Fibrous, green-brown. N G104 0642E015R05105112009B0012 LUV Sparsely plagioclase phyric basalt Subophitic to intergranular Flow 12 Plagioclase 4 4 1.5 An60 Subhedral Laths, glomerophyric. Plagioclase Clinopyroxene Olivine Magnetite 50 20 7 5 50 20 7 5 0.3 0.3 0.15-0.3 0.1-0.2 An50 Augite Laths N/A Subhedral, equant Subhedral Altered to iddingsite then smectite. Intergranular, anhedral also. Vesicles 10 3-6 Subround Carbonate centers, smectite rims. Clays 10 Intergranular Also altering olivine. Carbonate in vesicles radiates from a single point. Probably piece number 9B. Y G104 0642E016R01022024003 0015 LUV Medium grained mixed basalt Flow 15, mixed flow top Plagioclase Clinopyroxene Magnetite Clay 40 45 6 9 40 45 6 9 0.2 0.15-0.3 0.1-0.2 N/A An52 Laths N/A N/A N/A Intergranular and intersertal. Replacing clinopyroxene. Plagioclase Clinopyroxene Magnetite Clays? 35 5 5 55 35 5 5 55 0.3 0.1-0.3 0.05-0.1 N/A N/A Euhedral to subhedral N/A N/A Very thin laths or columns. Better developed than plagioclase. Vesicles 0 Domains of medium grained separated by fine grained or quenched material. Sharp boundary between fine and medium grained material. Probably piece number 3. N G104 0642E016R01032034004 0015 LUV Medium grained basalt Flow 15, mixed flow top Olivine Plagioclase Clinopyroxene Magnetite Clay 5 35 20 10 30 5 35 20 10 30 0.3 0.5-1.0 0.3 N/A N/A An52 N/A Stubby laths N/A N/A N/A Iddingsitized. Intergranular, replacing clinopyroxene. Plagioclase Clinopyroxene Magnetite Clay 45 2 8 45 45 2 8 45 0.1-0.4 0.07-0.25 0.035-0.090N/A Laths to columns Subhedral N/A N/A Altered groundmass. Vesicles 15 0.1 Fine grained portion Dark green clay Irregular Intergranular. Domain of medium grained separated by fine grained material, sharp boundaries between them. N G104 0642E017R01104106019 0017 PAR Red-weathered aphyric basalt Weak pilotaxitic Flow 17, weathered top, 1m below top. Olivine Plagioclase Clinopyroxene Opaques 20 40 35 5 20 40 35 5 0.05-0.2 0.05-0.2 0.05-0.1 0.025-0.1 An56 Euhedral-subhedral Subhedral, laths Anhedral Interstitial Iddingsitized throughout-red-brown, completely iddingsitized cores of olivine may hold calcite. Very weakly zoned, locally weakly pilotax. Vesicles 0 Clays Clays Carbonate Oxide? Fe-oxide ~5 Plagioclase Vein margins Veins 0.5-1.5 mm Vein fill Intergranular Green smectite: first phase vein fill smectite. Green-brown smectite growth, late celadonite. Sparry, with relict dog tooth and colloform growth rings. Local earliest pre-smectite vein margin growth. Weathering. Probably piece number 19. N G104 0642E017R02104107015 0017 PAR Weakly reddened basalt Weak trachytic Flow 17, 2.6 m below recovered flow top. Plagioclase 1-2 1-2 .8-.4 An65 N/A Zoned (An55 on outer rim). Olivine Plagioclase Clinopyroxene Opaque 15 45 37 3 15 45 37 3 0.1-0.5 0.1-0.4 0.05-0.1 < 0.05 An53 Magnetite Subhedral Subhedral, lath Anhedral Subhedral and interstitial Some euhedral and anhedral. Iddingsite pseudomorphs. Weak trachytic/pilotaxitic. Vesicles Cavities 7 < 1 2.5-5.0 < 1.0 Unfilled Smectite/carbonate/calcite Round Narrow, oxide staining around vesicle. Cavities and vein fill-carbonate 95%. Clays Clays Fe-oxode? Celadonite 7-10 Plagioclase and margins To olivine/green smectite. Yellow/brown smectite vein fill second phase. Vein margin first phase, localized. Vein margin third phase, pre-calcite. 3-5mm xenolith of basalt identified within thin section. Black, dusty margin to finer grained groundmass with moderate to strong pilotaxitic texture. N G104 0642E017R03070072006 0017 PAR Aphyric tholeiitic basalt Flow 17, 3.7m below recovered flow top. Plagioclase < 1 < 1 2-5 An60 Euhedral tabules Center margin normally zoned, locally glomerophyric. Olivine Plagioclase Clinopyroxene Oopaque 15 45 33 7 15 45 33 7 0.1-0.3 0.1-0.3 0.05-0.15 0.05-0.15 An58-60 Magnetite Subhedral-anhedral Subhedral-laths Anhedral Subhedral-interstitial All smectite or iddingsite in alteration zones. Weak/sporadic pilotaxitic. Some rhombics. Vesicles 0 Clays Clays < 3 10 (?) Cavities and margins Interstices or plagioclase Yellow brown smectite, radiofibrous. Patchy, in alteration fabric. Patchy, smectite-rich alteration zones, plagioclase (locally replaced 80% by green smectite), altered olivines are iddingsite-rich, c.f. to smectite-rich outside zones. Plagioclase is relatively fresh. Open fracture cutting section has altered margins. N G104 0642E018R02027029011B0017 PAR Streaky aphyric basalt Locally trachytic Flow 17, 5.4 m below recovered flow top. Olivine Plagioclase Clinopyroxene Opaques 12 45 35 8 12 45 35 8 0.1-0.6 0.1-0.3 0.05-0.1 < 0.15 Magnetite Subhedral to euhedral Subhedral, laths Anhedral Subhedral, few rhombics Iddingsite margins, smectite cores. Cleanest alteration textures in olivines in alteration zones. Local moderate pilotaxitic. Vesicles 0 Clays N/A Plagioclase (+ cpx?) Green smectite to maximum of 65% of discrete alteration zones (streaky laminations(?)). Zones make up 10% of rock, about 1mm wide, discontinuous, approximately parallel or patchy. Clearest alteration textures in olivines in alteration zones. Preferred orientation of plagioclase groundmass only locally subparallel to alteration streaking. N G104 0642E018R02027028011B0017 PAR Streaky tholeiitic basalt Subophitic/trachytic Flow 17, 6.7 m below recovered flow top. Plagioclase Olivine Clinopyroxene Opaques 50 12 33 5 50 12 33 5 0.2-0.65 0.1-0.5 0.05-0.15 0.075-0.15 An60 (?) Pigeonite Magnetite Subhedral laths Anhedral to subhedral Anhedral, granular Needles/rhombic, euhedral Moderate trachytic/pilotaxitic, deflection into alteration fabric. Olivines are dirty green smectite replacements outside of alteration streaks, clearly defined within streaks as part iddingsite, part smectite. Sub-ophitic with plagioclase. Vesicles 0 Clays N/A Interstices and locally plagioclase In alteration streaks/bands. Within alteration bands rock is up to 45% smectite, 1.0+ mm wide discontinuous, locally diffuse. N G104 0642E018R03072075001B0017 PAR Aphyric tholeiitic basalt Trachytic/pilotaxitic glomerophyric Flow 17, 8.5 m below recovered flow top. Palgioclase < 2 < 2 0.1 An65 Subhedral Locally glomerophyric. Olivine Plagioclase Clinopyroxene Opaques 12 42 37 8 12 42 37 8 0.1-0.35 0.1-0.4 0.025-0.2 0.05-0.1 An60 Anhedral Subhedral, anhedral, laths Anhedral, granular Anhedral-subhedral Iddingsite within alteration fabric and smectite replaces olivine outside alteration fabric, little iddingsite. Smectite in alteration zones, moderate pilotaxitic. Fresh. Fresh. Vesicles 0 Clays N/A Plagioclase Strongly altered in alteration "streak" zones. Poor alteration fabric, patches and single streak. N G104 0642E018R04037039002 0017 PAR Aphyric tholeiitic basalt Trachytic/pilotaxitic Flow 17, flow interior Olivine Plagioclase Clinopyroxene Opaque 12 42 38 8 12 42 38 8 0.1-1.0 0.1-0.5 0.05-0.15 0.05-0.2 An65 Magnetite Anhedral Lath, subhedral Anhedral, granular Anhedral Smectite and iddingsite replacement. Iddingsite only within alteration zones. Good pilotaxitic text, domainal. Vesicles 0 Clays Carbonate N/A < 1 Interstitial and plagioclase Cavity fills In alteration zones, green smectite. Alteration zones are well developed, about 1 mm wide, green smectite rich, with good alignment of feldspar laths within zones. Probalbly piece number 2. N G104 0642E019R01042044004C0018 LEH Sparsely phyric tholeiitic basalt Glomerophyric Flow 18, 0.6 m below recovered flow top. Plagioclase Clinopyroxene 2 N/A 2 N/A 1-2 < 1 An65 Pigeonite? Tabular and laths Laths Normally zoned, locally glomerophyric Olivine Plagioclase Clinopyroxene Opaques 12 40 38 5 12 40 38 5 0.1-0.4 <0.1-0.5 0.05-0.15 < 0.1 Magnetite Subhedral-anhedral Subhedral, laths N/A Interstitial Iddingsitized, rims mostly smectite psuedomorphs. Vesicles 7 4 Smectite calcite cores Irregular Radio-fibrous green smectite fill, yellow smectite rims. Clays 3 Interstitial and plagioclase Smectite patches. N G104 0642E019R02099102003 0018 LEH Tholeiite basalt Intersertal to subophitic Flow 18 Plagioclase 1 1 0.5-1.0 Prismatic Glomerophyric, zoned. Plagioclase Clinopyroxene Olivine Opaques ~40 ~40 5-7 2-3 ~40 ~40 5-7 2-3 0.2-0.6 0.1-0.3 0.05-0.5 < 0.15 2 Pyroxene? Laths Subhedral to anhedral N/A Euhedral Width is <0.05 mm. High 2V, > 40 degrees, purplish color, second cpx(?) has a very pale color, lower 2V (~30 degrees). Altered to iddingsite and clays. Some altered around edges (Fe stain). Vesicles N/A < 10 Ovoid Filled with smectite and isotropic mineral. Clays 10 Interstices and vesicles Maybe two clinopyroxenes: 1) Augite with ~Ti (purplish color). 2) Pigeonite (very pale to colorless; 2V; lower extinction angle). N G104 0642E019R04009010001A0018 PAR Sparsely phyric tholeiitic basalt Subophitic Flow 18, 5.2 m below recovered flow top. Plagioclase > 1 > 1 0.1-1.2 AN60 Tabular and laths Fresh, most normally zoned, few oscillatory. Olivine Plagioclase Clinopyroxene (x2) Opaques 10 41 39 4 10 41 39 4 0.1-0.5 0.1-0.9 0.05-0.1 0.05-0.2 An60 Pigeonite + ? Magnetite Subhedral or anhedral N/A N/A N/A Iddingsitized and smectite replaced. 2V ~0 degrees/+2V ~45 degrees, some subophitic. Vesicles 0 Clays 5 Green smectite rich alteration patches. Probably piece number 1A. N G104 0642E027R03015019014 0029 LEH Plagioclase-phyric tholeiitic basalt Hyalocrystalline or trachylitic Flow 29 Plagioclase 1 1 0.5-2.5 Prismatic Glomerophyric, fractured, partially altered. Tachylite Plagioclase Clino-orthopyroxene 40 40 3-5 40 40 3-5 N/A N/A 0.15-0.35 Pigeonite Interstitial N/A Euhedral Opaque, "isotropic", cryptocrystalline. Inverted pigeonite, i.e. opx with augite lamellae. Vesicles Lots 1-3 Smectite, zeolite Irregular Some with center voids. Clays 12-15 Fractures in plagioclase phenocrysts Also altering large plagioclase, interstitial. N G104 0642E027R04066068008A0029 DIV Lehgioclase-phyric basalt Intersertal Flow 29 Plagioclase 10-12 10-12 1.0-2.5 Prismatic Tend to be fractured and/or embayed. Plagioclase Clinpyroxene Olivine Opaques 35 5 2-3 5 35 5 2-3 5 0.05-0.2 N/A < 0.05 0.1-0.2 Augite Fe3O4 Laths N/A Euhedral to subhedral Skeletal Occasional laths up to 0.7 mm. Mostly altered, percentage is for partially altered. Replaced by brown smectite (counted as olivine). Some oxidation, tend to cluster near vesicles. Vesicles 5 > 0.5 Smectite Round Not counted in mineral totals. Clays Clays 15 30 Interstitial Pyroxene (and plagioclase?) Uniform brown. Splotchy appearance. Plagioclase laths radiate from (altered) olivine. Opaques and (altered) olivine are often concentrated in linear bands and around vesicle rims. N G104 0642E027R05011015001 0029 LEH Plagioclase-clinopyroxene phyric basalt Intersertal to subophitic Flow 29 Plagioclase Clinopyroxene 12 2 12 2 1-2 0.7-1.0 Pigeonite, augite Prismatic Subhedral Glomerophyric, subophitic. 2V <2.5 degrees, + very pale pigeonite to low Ca Augite, slight brown tinge. Plagioclase Clinopyroxene Opaques 45 35 3-5 45 35 3-5 0.05-0.6 < 0.05 N/A Laths Subhedral to anhedral Euhedral to skeletal Size: 0.05-0.6 length, ~0.5 width. Vesicles 15 1-20 Smectite and zeolite Elongate, irregular Clays 3-5 Interstices Medium brown. Minerals are quite fresh. N G104 0642E067R01121123026 0074 LEH Altered aphyric basalt (?) hyalocrystalline to intersertal Flow 74 Medium Plagioclase Clinopyroxene Olivine Opaques 20 15 3-5 20 20 15 3-5 20 0.2-2.0 0.05-0.2 0.1-1.0 N/A Augite Laths, prisms Subhedral to anhedral Euhedral to subhedral N/A Prismatic crystalls tend to be more altered. Nearly colorless, hourglass extinction. Completely altered to iddingsite. Fe-Ti oxides (altered) plus tachylite(?) in interstices. Vesicles 15 0.1-3.0 Smectite and zeolite Rounded to irregular Clays Clays 10 30 Interstices Feldspar, cpx, "groundmass" Light green smectite, well crystallized. Dark green smectite, micro- or cryptocrystalline. N G104 0642E067R02052054012 0074 LEH Aphyric tholeiitic basalt Intersertal Flow 74 Medium Plagioclase Clinopyroxene Olivine Opaques 40 25 2 3 40 25 2 3 0.05-1.5 0.1-0.6 ~0.1 N/A Pigeonite and augite Laths and prismatic Subhedral to anhedral Euhedral to subhedral Interstial, skeletal, subhedral Very pale green, low 2V, positive, hourglass extinction. Altered to smectite, some iddingsitization. Vesicles 15 0.2-1.5 Smectite Round Clays 30 Interstices Light greenish brown. Magnetite, nice skeletal structures, polishing scratches observable in reflected light under XP, also hematite. N G104 0642E097R01054056017 0106 LEH Throughly altered flow Quenched Flow 106 Plagioclase 2 2 < 0.1 Prismatic Plagioclase 7 7 N/A Swallowtail Quenched. Skeletons of incipient crystals, quenched, altered. Vesicles 0 Clays 90 All Cryptocrystalline. Thin section has been almost completely wiped during processing, possible relict perlitic structures. N G104 0642E098R01106108014 0109 LEH Altered quenched flow Quenched, altered Flow 109 Plagioclase 1 1 0.1-1.2 Prismatic Mildly to severely altered. Plagioclase 10 10 N/A Swallowtail Quenched, altered percentage is for distinguishable plagioclase. Vesicles 20 Smectite-analcite-mordenite-adularia, in from rims. Clays 90 All Quenched textures preserved. Alteration assemblage typical of 100 - 150 degree C fluid. N G104 0642E098R02062064013 0109 LEH Perlite (glassy flow) Perlitic Flow 109 Plagioclase 2 2 0.2-1.3 Prismatic Tends toward glomerophyric. Glass 98 98 N/A N/A Altered to perlite, light purplish brown. Vesicles 5 Smectite and zeolite Round Also includes fractures. N G104 0642E099R03013015001 0112 LEH Altered quenched flow Quenched Flow 112 Plagioclase Clinopyroxene(?) 15 15 15 15 N/A N/A Swallowtail to skeletal Acicular Quenched. Incipient crystal growth. Vesicles 0 Clays Carbonate 70 > 1 All Feldspars Light greenish brown and brown smectites(?). Biaxial, negative, very high birefringence, colorless, rhombic cleavage. N G104 0642E102R02026028007 0115 LEH Hydrothermally leached glassy flow Bleached Flow 115 Plagioclase 3-5 3-5 0.1-1.5 Prismatic Glomerophyric. Pyrite << 1 << 1 N/A Skeletal Replaced (reflected light). Vesicles N/A None Round Clays 95 All minerals Cryptocrystalline. Rock has been leached white. N G104 0642E107R02124126011 0006 LEH Shallow level basalt dike Hyalocrystalline Dike 6 Opaques Plagioclase Clinopyroxene Glass 40 < 1 40 10 40 < 1 40 10 N/A 0.05-0.7 N/A N/A N/A Laths N/A N/A Tachylite? and pyrite. Dark brown. Vesicles 0 Clays(?) 10 Interstices May be incipient crystallization structures? Grain size of plagioclase increases, amount of glass increases, pyrite increases near vein-like structure; no apparent increase in alteration. N