Thin Sections Reservation

Site U1362 core descriptions Thin sections reservation. p ined by an increase in the proportion of dark reservation. p onite. Moderate p onite onite onite p brown sa p p y sa y sa sa y y laced b p laced b laced b laced b p re p p y onite. onite and oxides. Moderate p p Partiall core. sa between iron oxyhydroxides only, saponite only and iron oxyhydroxides lining between iron oxyhydroxides only, sa Generally present on polymineralic glomeroporphyritic clots with plagioclase. 100% re Mostly acicular. Occurs singly and occasionally in polymineralic glomeroporhyritic Mostly acicular. Celadonite lining saponite-iron oxyhydroxides mix, layered celadonite - saponite Mixed iron oxyhydroxides and saponite vein fill. Composition alters along saponite - saponite-iron oxyhydroxides mix, saponite-celadonite mix lining celadonite - saponite-iron oxyhydroxides mix, layered fibrous clots with anhedral subrounded clinopyroxenes. Partially replaced by brown celadonite-iron oxyhydroxides mix core, celadonite lining - iron spherical moderately SIZE(mm) SIZE(mm) THICKNESS(mm) 80 0.1 0.72 0.36 Groundmass almost entirely replaced by saponite and iron oxyhydroxides mix, which forms a spherulitic texture. 3 mm halo is def red/brown iron oxyhydroxides to light brown saponite and is directly related oxyhydroxides-saponite vein. THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 55-60 cm 327-U1362A-2R-1-W, pillow interior (alteration halo) PRIMARY sparsely plagioclase clinopyroxene phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS cryptocrystalline clinopyroxene Piece No: 8 PRESENT PERCENT Unit: 1A REPLACED VOL PERCENT min.THIN SECTION 5 JR, OBSERVER: max. mode 26 MORPHOLOGY COMMENTS 0.1 0.3 0.3 round plagioclasemesostasis 2 <0.1 0.4 <0.1 acicular 98% re SECONDARY MINERALOGY oxidessaponiteiron oxidesVESICLESMINERALOGYsaponite, celadonite, iron MODAL PERCENT ABUNDANCE 1 70 20 PERCENT FILLED min. max. mode SHAPE COMMENTS SUMMARY DESCRIPTION SUMMARY plagioclase 40 0.2 1.4 1 euhedral GROUNDMASS pyroxene <0.1 0.12 0.1 subhedral 99% re VEINSsaponite, iron oxides mixed FILLING <0.1 irregular SHAPE COMMENTS oxides U1362A-2R-1-W, 55-60 cm 55-60 U1362A-2R-1-W,

Proc. IODP | Volume 327 1 Site U1362 core descriptions Thin sections reservation. p h g in. Hi g chilled mar y lass g network. hout g g es within a branchin p roxene. Present throu py sha chilled margin. These have complex generation relationships and variable chilled margin. Fresh amber glass forming outer chilled margin Dark altered glass with abundant fibrous spherulites Saponite lining saponite Occurs as laths and acicular needles, but often glomeroporphyritic clots with COMMENTS COMMENTS Multigeneration saponite veins both perpendicular and sub-parallel with glassy herical p s cross-cut moderately 1.6 SIZE(mm) SIZE(mm) THICKNESS(mm) 52 0.2 0.1 1.1 1.2 0.8 0.3 euhedral subhedral Occurs in glomeroporphyritic clots with plagioclase. High preservation. 50 <0.1 0.5 0.4 FILLING SHAPE 22 <0.1 0.1 0.1 acicular Microlaths 25 72 70 <1 <0.1 0.8 0.1 anhedral PRESENT REPLACED min. max. mode MORPHOLOGY COMMENTS PERCENT VOL PERCENT ABUNDANCE FILLED min. max. mode SHAPE PERCENT MODALPERCENT PERCENT sparsely plagioclase clinopyroxene phyric microcrystalline basalt chilled pillow margin microcrystalline THIN SECTION:ROCK NAME: WHERE SAMPLED: GRAINSIZE: TEXTURE: 121-126 cm 327-U1362A-2R-1-W, PRIMARY MINERALOGY PHENOCRYSTS plagioclase Piece No:pyroxene GROUNDMASS glass pyroxene plagioclase Unit: 1Amesostasis SECONDARY MINERALOGY THIN SECTION 6 JR, OBSERVER: saponite celadonite VESICLES MINERALOGY saponite VEINS saponite DESCRIPTIONSUMMARY All but one veins are associated with radial cooling cracks of chilled margin. U1362A-2R-1-W, 121-126 cm 121-126 U1362A-2R-1-W,

Proc. IODP | Volume 327 2 Site U1362 core descriptions Thin sections ioclase g la p ritic clots with y h p or p lomero g reservation. p in onite. y p , sa e occurs throughout. g onite linin p roxene. Moderate lining with iron oxyhydroxides core, celadonite saponite celadonite lining with iron oxyhydroxides core. Non-alteration halo vesicle fill: Alteration halo vesicle fill: iron oxyhydroxides, saponite-iron oxyhydroxides mix Occurs singly (acicular) and laths as polymineralic glomeroporphyritic clots with Often very irregular in shape as many vesicules have coalesced into vugs. Microlites associated with saponite Abundant red-brown fibrous saponite spherulites 0.8 mm fresh amber glass on chilled pillow margin sa py <0.1<0.1 irregular irregular Perpendicular to chilled margin. Subparallel with chilled margin - saponite fills radial cooling crack SIZE(mm) SIZE(mm) THICKNESS(mm) ) e alteration halo g 75 0.1 0.7 0.5 slightly spherical oran ( in g illow interior/sub-mar p THIN SECTION:ROCK NAME:WHERE SAMPLED: GRAINSIZE:TEXTURE: 73-76 cm 327-U1362A-2R-2-W, PRIMARY cryptocrystalline basalt MINERALOGYPHENOCRYSTS cryptocrystalline plagioclase Piece No: 8 PRESENT PERCENT Unit: 1A REPLACED VOL PERCENT min.THIN SECTION 7 JR, OBSERVER: max. mode MORPHOLOGY COMMENTS 10 0.4 1.7 1.1 euhedral VEINSsaponite saponite DESCRIPTIONSUMMARY Saponit iron oxyhydroxides and celadonite occur as vesicle fill associated with orange alteration halo only. FILLING SHAPE COMMENTS pyroxene 10 0.1 0.18 0.18 anhedral Rounded. Normall GROUNDMASS opaque mineralsplagioclasemesostasisglassSECONDARY MINERALOGY celadoniteoxides 2 iron oxidessaponite 3VESICLES 68 MINERALOGYsaponite, celadonite, iron 3 3 MODAL PERCENT 2 ABUNDANCE 2 PERCENT 70 FILLED <0.1 0.24 min. max. 0.1 mode acicular SHAPE Microlaths. fewer towards glassy chilled margin COMMENTS oxides U1362A-2R-2-W, 73-76 cm 73-76 U1362A-2R-2-W,

Proc. IODP | Volume 327 3 Site U1362 core descriptions Thin sections ioclase g la p sts and mesostasis ioclase y g la p ritic clots with y h heonocr p p or x p p + rown with g g la p lomero g in y ate needles. roundmass, g g

g groundmass. lacin as elon p y resent in extent of alteration halo roxenes, normall l p g py core. Occurs sin (background alteration): saponite lining, lining with carbonate Laths in mono- and polymineralic glomeroporphyritic clots with pyroxene. Vesicle fill Vesicle Vesicle fill (dark grey alteration halo): saponite lining, celadonite lining Vesicle Vesicle fill, Vesicle Vesicle fill, replacing groundmass and mesostasis in extent of alteration halo Vesicle fill, re Vesicle lining with iron oxyhydroxides core, oxyhydroxides, celadonite saponite core, layered celadonite - iron oxyhydroxides - saponite. Vesicle fill saponite core, layered celadonite - iron oxyhydroxides saponite. Vesicle SIZE(mm) SIZE(mm) THICKNESS(mm) 2 60 0.2 0.62 0.6 highly spherical PERCENT MODALPERCENT PERCENT THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 141-146 cm 327-U1362A-3R-1-W, dark grey halo and patchy background alteration pillow interior, PRIMARY basalt MINERALOGYPHENOCRYSTS cryptocrystalline Plagioclase Piece No: 17 intersertal, glomeroporphyritic sub-ophitic, Unit: 1A PRESENT PERCENT ORIGINALTHIN SECTION 8 JR, OBSERVER: PERCENT min. 7.2 max. mode MORPHOLOGY 8 COMMENTS 0.2 1.5 0.7 euhedral carbonate trace VEINSN/A DESCRIPTIONSUMMARY Alteration halo defined by celadonite and iron oxyhydroxides vesicle fill replacement of mesostasis FILLING SHAPE COMMENTS iron oxides 2 Pyroxene 1.4 1.6 <0.1 0.5 0.4 anhedral Rounded Opaque MineralsSECONDARY MINERALOGY celadonitesaponite 2 12 51 <0.1 GROUNDMASS plagioclasemesostasispyroxene 15 3 4 43 10 26 0.1 <0.1 0.8 <0.1 0.8 <0.1 acicular anhedral Microlaths and needles Microlites. Occurs attached to or inter altered to saponite Mostly VESICLESsaponite, celadonite, iron ABUNDANCE FILLED min. max. mode SHAPE COMMENTS oxides, carbonate U1362A-3R-1-W, 141-146 cm 141-146 U1362A-3R-1-W,

Proc. IODP | Volume 327 4 Site U1362 core descriptions Thin sections lace mesostasis. roxene celadonite, saponite lining with iron oxyhydroxides core, layered mixed py + celadonite, celadonite, saponite, celadonite, iron oxyhydroxides. Vesicle fill + celadonite, saponite, iron oxyhydroxides. Vesicle alteration halo Occurs singly and as mono- polymineralic glomeroporphyritic clots with Celadonite filling vesicles, replacing mesostasis and olivine, all associated with COMMENTS COMMENTS Vesicle fill (alteration halo): celadonite lining with iron oxyhydroxides core, Vesicle Saponite filling vesicles, replacing groundmass, phenocrysts and mesostasis iron oxyhydroxides filling vesicles associated with alteration halo Oxides replacing mesostasis (background alteration): saponite lining, empty. spherical moderately SIZE(mm) SIZE(mm) THICKNESS(mm) 5.2 35 <0.1 0.6 0.5 oxides cladonite, saponite, iron THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 79-81 cm 327-U1362A-3R-2-W, pillow interior (multilayer alteration halo) PRIMARY basalt MINERALOGYPHENOCRYSTS pyroxene cryptocrystalline Piece No: 12 intersertal vesicular, subophitic, plagioclaseolivineGROUNDMASS plagioclase PRESENT Unit: 1A PERCENTpyroxenemesostasis ORIGINAL PERCENT SECONDARY THIN SECTION 9 JR, OBSERVER: MINERALOGY min.saponite 2 4.8 max. trace 12 mode MORPHOLOGY 10 2.2VESICLES COMMENTS 6 5MINERALOGY 1 0.2 20 0.4 49 18 52 1.28 MODAL PERCENT VEINS 0.7 ABUNDANCE <0.1 1.52 PERCENT N/A <0.1 0.3 DESCRIPTIONSUMMARY FILLED 0.8 1.2 Multilayered green and dark grey halo contains iron oxyhydroxides celadonite which fill vesicles rep 1 0.2 min. 0.4 euhedral 0.1 max. acicular mode anhedral anhedral Pseudomorphed by saponite and celadonite Rounded. Entirely pseudomorphed by celadonite and saponite Pseudomorphed by saponite and celadonite SHAPE FILLING entirely replaced by saponite Almost SHAPE iron oxidesoxidesceladonite 2 1 9 U1362A-3R-2-W, 79-81 cm 79-81 U1362A-3R-2-W,

Proc. IODP | Volume 327 5 Site U1362 core descriptions Thin sections COMMENTS COMMENTS Vesicle fill: saponite lining, iron oxyhydroxides/opaque oxide lining Vesicle Saponite replacing groundmass, mesostasis and olivine, filling vesicles iron oxyhydroxides filling vesicles, replacing mesostasis Oxides filling vesicles, replacing mesostasis herical p slightly s SIZE(mm) SIZE(mm) THICKNESS(mm) PERCENT 9.8 5 <0.1 1.2 0.4 PERCENT MODAL PERCENT MINERALOGY ABUNDANCE FILLED min. max. mode SHAPE THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE: TEXTURE: 71-76 cm 327-U1362A-4R-1-W, pillow interior PRIMARY basalt MINERALOGYPHENOCRYSTS olivinepyroxene Piece No: 11plagioclaseGROUNDMASS plagioclasepyroxene PRESENT PERCENTolivine Unit: 1Amesostasis ORIGINAL PERCENT SECONDARY THIN SECTION:10 JR, OBSERVER: MINERALOGY min.saponite 1.5 0 8 max. 20 mode 7 MORPHOLOGY COMMENTS 0 2 0 8.5 4 35VEINSN/A <0.2 48 21 0.7 0.3 DESCRIPTIONSUMMARY 18 Patchy background alteration defined by more intense replacement of mesostasis and groundmass saponite. 4 0.4 1.6 0.7 0.3 1.4 0.3 <0.1 subhedral euhedral subhedral Occurs as glomeroporphyritic clots with plagioclase 0.2 <0.1 Predominantly occurs singly but occasionally as glomeroporphyritic clots Completely replaced by saponite subhedral euhedral 0.2 FILLING <0.2 Occurs attached to or intergrown with plagioclase Needles and laths euhedral euhedral Mesostasis is uniformly altered Entirely pseudomorphed by light brown saponite SHAPE iron oxidesoxidesVESICLES 2 3 U1362A-4R-1-W, 71-76 cm 71-76 U1362A-4R-1-W,

Proc. IODP | Volume 327 6 Site U1362 core descriptions Thin sections onite. p , sa y t p , em g onite linin p : sa ) round g roxene. back core, celadonite+saponite mix with iron oxyhydroxides core. Vesicle fill core, celadonite+saponite mix with iron oxyhydroxides core. Vesicle Vesicle fill (alteration halo): celadonite. celadonite lining with iron oxyhydroxides Vesicle Occurs singly and as mono- poly mineralic glomeroporphyritic clots with COMMENTS COMMENTS fill lost Vein iron oxyhydroxides filling vesicles Saponite replacing mesostasis Celadonite replacing mesostasis and filling vesicles ( py herical p s y htl g sli 0.3 irregular SIZE(mm) SIZE(mm) THICKNESS(mm) 3 25 0.1 0.6 0.4 celadonite, saponite, iron THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: cm 112-114 327-U1362A-5R-1-W, pillow interior (green alteration halo) PRIMARY sparsely plagioclase clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS pyroxene microcrystalline Piece No: 20 intersertal, glomeroporphyritic, pilotaxitic plagioclaseGROUNDMASS pyroxene Unit: 1Bplagioclase PRESENT PERCENTopaque mineralsmesostasis ORIGINALTHIN SECTION 11 PERCENT JR, OBSERVER: SECONDARY MINERALOGY min. <1iron oxidessaponite 5 max.celadonite 4 35VESICLES 27 modeMINERALOGY <1 MORPHOLOGY COMMENTS 0 7 <0.1 4 37 29VEINS 1 MODAL PERCENT ABUNDANCE 0.6 PERCENT 20 15 0.6 5 DESCRIPTIONSUMMARY <0.1 0.1 Alteration halo defined by celadonite filling vesicles. FILLED 2 0.2 0.2 min. 0.9 <0.1 subhedral 1.2 0.1 max. <0.3 Occurs in glomeroporphyritic clot with plagioclase mode euhedral anhedral Partially replaced by brown saponite SHAPE FILLING SHAPE oxides U1362A-5R-1-W, 112-114 cm 112-114 U1362A-5R-1-W,

Proc. IODP | Volume 327 7 Site U1362 core descriptions Thin sections g onite linin p onite, sa p roxene py Most frequently occurs singly but also in glomeroporphyritic clots, sometimes COMMENTS COMMENTS Iron oxyhydroxides replacing olivine and groundmass Saponite replacing groundmass and filling vesicles Oxides replacing groundmass with herical fill: sa Vesicle p s SIZE(mm) SIZE(mm) THICKNESS(mm) THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 20-23 cm 327-U1362A-5R-2-W, unit boundary PRIMARY moderately olivine clinopyroxene plagioclase phyric crypto to microcrystalline basalt MINERALOGYPHENOCRYSTS pyroxene crypto to microcrystalline Piece No: 3 pilotaxitic to intersertal, glomeroporphyritic, vesicular, subophitic plagioclaseOlivineGROUNDMASS pyroxene PRESENT Unit: 1B PERCENTolivineplagioclase ORIGINALmesostasis PERCENT min.SECONDARY 1.1MINERALOGY THIN SECTION 12 JR, OBSERVER: 8.5iron oxides max.saponiteoxides mode 0 10 1.1VESICLESMINERALOGY 28 8.5 MORPHOLOGYsaponite 0 2 COMMENTS 0.1VEINS 0.9 1N/A 24 2 16 0.5 DESCRIPTIONSUMMARY MODAL PERCENT ABUNDANCE Grain size change across the thin section from crypto to microcrystalline. PERCENT <1 30 1.3 49 <0.1 FILLED <0.1 0.3 3 <0.1 1.1 0.2 min. 5.5 0.9 0.2 subhedral 0.18 max. euhedral 0.2 Occurs mostly in glomeroporphyritic clots with plagioclase <0.1 mode 0.2 5 anhedral acicular FILLING subhedral SHAPE Altered to saponite, occurs singly or attached to/intergrown with plagioclase. <0.1 Entirely pseudomorphed by saponite 0.8 Compeltely pseudomorphed by saponite 0.4 SHAPE U1362A-5R-2-W, 20-23 cm 20-23 U1362A-5R-2-W,

Proc. IODP | Volume 327 8 Site U1362 core descriptions Thin sections . g onite linin p ioclase needles. , sa g y t la p sicles. p : em ) rown with g alteration halo celadonite lining with iron oxyhydroxides - saponite core. Vesicle fill (non celadonite lining with iron oxyhydroxides - saponite core. Vesicle celadonite - pale pure (imaged); lining with saponite core; Partially replaced by light brown saponite and olive green celdaonite. Attached Partially replaced by light brown saponite and olive green celdaonite. Celadonite replaces mesostasis and fill vesicles within alteration halo iron oxyhydroxides replace mesostasis and fill vesicles within alteration halo Saponite replaces mesostasis and olivine, fills vesicles Vesicle fill (alteration halo): multilayered: saponite - celadonite Vesicle to/inter SIZE(mm) SIZE(mm) THICKNESS(mm) 7.2 70 <0.1 0.9 0.7 slightly spherical THIN SECTION:ROCK NAME: WHERE SAMPLED:GRAINSIZE: TEXTURE: 39-41 cm 327-U1362A-6R-1-W, pillow interior (alteration halo) PRIMARYMINERALOGYPHENOCRYSTS olivineplagioclase hyalophytic, intersertal, glomeroporphyritic pyroxene Piece No: 10GROUNDMASS pyroxene PRESENT PERCENT Unit: 1B ORIGINAL PERCENT THIN SECTION 13 JR, OBSERVER: min. 9 0 max. 3 mode 22 MORPHOLOGY COMMENTS 11 2 3 24 1 0.1 <0.1 2.9 <0.1 0.9 0.5 0.1 1.6 0.7 0.1 0.1 euhedral anhedral subhedral Occurs singly and often as glomeroporphyritic clots with pyroxene Completely pseudomorphed by saponite Occurs as glomeroporphyritic clots with plagioclase. subhedral plagioclasemesostasisolivineSECONDARY MINERALOGY celadoniteoxidesiron oxidessaponite 30VESICLES 0MINERALOGYsaponite, celadonite, iron 0 30 6 19 MODAL PERCENT 2 ABUNDANCE 1 PERCENT <0.1 20 3 FILLED 0.7 min. <0.1 <0.3 max. 0.2 acicular mode <0.2 Laths and needles SHAPE anhedral COMMENTS Microlites completely psuedomorphed by saponite replaced by saponite Entirely VEINSN/A DESCRIPTIONSUMMARY Alteration halo defined by presence of celadonite and iron oxyhydroxides replacing groundmass filling ve FILLING SHAPE COMMENTS oxides U1362A-6R-1-W, 39-41 cm 39-41 U1362A-6R-1-W,

Proc. IODP | Volume 327 9 Site U1362 core descriptions Thin sections droxides core. y h y on, defined by presence of celadonite and iron oxyhydroxides alteration halo fill: saponite lining. Vesicle fill of those associated with small alteration halo: fill: saponite lining. Vesicle Saponite replaces olivine and mesostasis. Celadonite replaces groundmass and fills vesicles associated with green Iron oxyhydroxides replace groundmass and fill vesicles associated with green Vesicles have coalesced in several places to form irregular shaped vugs. Vesicle have coalesced in several places to form irregular shaped vugs. Vesicle Vesicles celadonite, celadonite with iron ox alteration halo herical p s y htl g sli SIZE(mm) SIZE(mm) THICKNESS(mm) 3.2 3 <0.1 2.5 0.4 filling vesicles. oxidesVESICLESMINERALOGYsaponite, celadonite, iron MODAL PERCENT ABUNDANCE PERCENT 1 FILLED min. max. mode SHAPE COMMENTS celadonite 2 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 74-77 cm 327-U1362A-6R-2-W, pillow interior PRIMARY moderately olivine plagioclase clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS olivine microcrystalline plagioclase Piece No: 14 glomeroporphyritic intersertal to intergranular, pyroxeneGROUNDMASS olivinemesostasis PRESENT Unit: 1B PERCENTpyroxeneopaque minerals ORIGINALplagioclase PERCENT THIN SECTION 17 JR, OBSERVER: SECONDARY min. 3.5MINERALOGY saponite 0 <0.1 max. trace mode 3 0 3.5 MORPHOLOGY 30 COMMENTS <0.1 43 1 0.7 0.3 15 4 0.2 27 13 4.8 38 0.4 0.3 1.1 0.4 0.3 euhedral anhedral Occurs singly as needles or in monomineralic glomeroporphyritic clots <0.3 <0.2 <0.2 <0.3 <0.3 euhedral euhedral Occurs singly or in monomineralic clots. Completely replaced by saponite euhedral Laths and needles Completely pseudomorphed by light brown saponite iron oxides trace VEINSN/A DESCRIPTIONSUMMARY Many vesicles have coalesced to form unfilled irregular vugs. Small alteration halo at one end of thin secti FILLING SHAPE COMMENTS oxides U1362A-6R-2-W, 74-77 cm 74-77 U1362A-6R-2-W,

Proc. IODP | Volume 327 10 Site U1362 core descriptions Thin sections hout g roundmass. g droxides within alteration halo . y g h y droxides stained y h y roundmass, olivine, mesostasis and fills vesicles throu thin section. g iron ox onite linin y p b g : sa laces iron ox ) y p ed stainin onite re non halo p ( p Stri more heavil fill Celadonite replaces mesostasis and fills vesicles in area of alteration halo Associated with plagioclase laths. Slightly altered by light brown saponite. Sa Iron oxyhydroxides replaces mesostasis and fills vesicles in area of alteration COMMENTS fill (alteration halo): iron oxyhydroxides, celadonite - saponite mix, Vesicle COMMENTS Composition alters along vein. Iron oxyhydroxides composition associated with halo celadonite lining with saponite core, iron oxyhydroxides orange - dark red - bright orange iron oxyhydroxides (imaged), saponite. Vesicle orange - dark red bright iron oxyhydroxides (imaged), saponite. Vesicle core, bright red-orange fill - pure iron oxyhydroxides?, layered golden SIZE(mm) SIZE(mm) THICKNESS(mm) 1 80 0.1 0.4 0.1 highly spherical THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 29-31 cm 327-U1362A-7R-1-W, large alteration halo PRIMARY sparsely olivine plagioclase clinopyroxene cryptocrystalline basalt MINERALOGYPHENOCRYSTS cryptocrystalline pyroxene glomeroporphyritic variolitic, plagioclase Piece No: 5GROUNDMASS pyroxeneplagioclase PRESENTmesostasis PERCENT Unit: 1Bopaque minerals ORIGINAL PERCENT SECONDARY MINERALOGY THIN SECTION 14 OBSERVER:JR, min.saponiteiron oxides 2.7 1 max.oxidesceladonite 3 1 8 mode trace MORPHOLOGYVESICLES COMMENTS 3MINERALOGY 1.2 60 20 15 66 0.2 0.6 7 MODAL PERCENT ABUNDANCEVEINS <0.1 0.3 PERCENT 0.1 10 1.6 2 saponite 10%, iron oxyhydroxides 90% FILLED <0.1 0.3 0.5 1.1 DESCRIPTIONSUMMARY Microvein cuts through crystals and seems associated with halo as both can be traced around two sides of the min. <0.1 subhedral <0.4 euhedral max. mixed anhedral occasionally as glomeroporphyritic clots with pyroxene Mostly occur singly, euhedral <0.1 Groundmass is highly altered to brown saponite mode Groundmass is highly altered to brown saponite SHAPE <0.1 FILLING and groundmass highly altered to dark brown saponite Mesostasis anastomosing SHAPE saponite, celadonite, iron oxides U1362A-7R-1-W, 29-31 cm 29-31 U1362A-7R-1-W,

Proc. IODP | Volume 327 11 Site U1362 core descriptions Thin sections nally left blank. left nally This page This page intentio U1362A-8R-1-W, 122-124 cm 122-124 U1362A-8R-1-W,

Proc. IODP | Volume 327 12 Site U1362 core descriptions Thin sections onite. p sa y hed b p seudomor saponite lining with celadonite core; celadonite; iron alteration halo saponite; iron oxyhydroxides/opaque oxide lining - celadonite iron oxyhydroxides filling vesicles within alteration halo Oxides filling vesicles within alteration halo Saponite replacing mesostasis and olivine, filling vesicles throughout Celadonite replacing groundmass and mesostasis, filling vesicles within Vesicle fill (alteration halo): multilayered: celadonite + saponite mix - Vesicle Vein crosscuts and sometimes encloses crystals. Associated olivines are entirely crosscuts and sometimes encloses crystals. Vein p oxyhydroxides core. Vesicle fill (background alteration): saponite, saponite lining. oxyhydroxides core. Vesicle spherical subhedral moderately euhedral to SIZE(mm) SIZE(mm) THICKNESS(mm) mixed 0.25 straight 1 75 0.1 0.9 0.6 olivineSECONDARY MINERALOGY iron oxidesoxidessaponiteceladoniteVESICLESMINERALOGY 0saponite, celadonite, 0.5 MODAL PERCENT 2 15 ABUNDANCE PERCENT 5.5 4 FILLED <0.1 min. 0.2 max. mode <0.2 SHAPE COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 122-124 cm 327-U1362A-8R-1-W, basalt flow interior (alteration halo) PRIMARY moderately olivine clinopyroxene phyric microcrystalline to fine-grained basalt MINERALOGYPHENOCRYSTS pyroxene to fine grained microcrystalline plagioclase Piece No: 18 to intersertal subophitic olivineGROUNDMASS plagioclasemesostasis PRESENT Unit: 2 PERCENTpyroxene ORIGINAL PERCENT THIN SECTION 15 JR, OBSERVER: min. 8 1 max. trace 23 14 mode MORPHOLOGY COMMENTS 8 1 30 1 27 28 0.3 1 <0.3 31 0.2 1 0.5 1 1.2 <0.1 0.8 0.4 1.6 0.8 0.6 subhedral subhedral <0.5 euhedral 0.8 completely replaced by saponite Occurs singly, Semi-rounded lath. euhedral Occurs singly Includes opaque minerals VEINSsaponite with glass FILLING SHAPE COMMENTS SUMMARY DESCRIPTIONSUMMARY Alteration halo and vein are not associated. Saponite is perpendicular to boundary. iron/opaque oxides inclusions U1362A-8R-1-W, 122-124 cm 122-124 U1362A-8R-1-W,

Proc. IODP | Volume 327 13 Site U1362 core descriptions Thin sections Saponite filling vesicles and replacing mesostasis Celadonite filling vesicles COMMENTS fill: celadonite lining with saponite core, bright green Vesicle COMMENTS herical p s moderately SIZE(mm) SIZE(mm) THICKNESS(mm) onite, celadonite 8 100 <0.1 0.6 0.6 p THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 125-128 cm 327-U1362A-9R-1-W, pillow lava interior PRIMARY sparsely clinopyroxene plagioclase microcrystalline basalt MINERALOGYPHENOCRYSTS olivine microcrystalline plagioclase Piece No: 20 to intersertal, glomeroporphyritic, pilotaxitic subophitic GROUNDMASS pyroxeneplagioclaseopaque minerals Unit: 4A PRESENT PERCENTmesostasis ORIGINALSECONDARY PERCENT THIN SECTION 16 JR, OBSERVER: MINERALOGY saponite min. 4.1celadonite 0VESICLES max. 3 27MINERALOGY 35 mode trace 4.1 MORPHOLOGY COMMENTS traceN/A 3 28 35 MODAL PERCENT 1.4 ABUNDANCE DESCRIPTION 22 SUMMARY PERCENT 10 0.6 8 Celadonite restricted to vesicle fill. FILLED <0.1 2.2 0.1 0.7 min. <0.3 <0.4 1.6 0.6 <0.1 max. 0.2 0.2 euhedral subhedral mode Occurs singly and as monomineralic glomeroporphyritic clots Completely pseudomorphed by brown saponite euhedral SHAPE sa VEINS FILLING SHAPE U1362A-9R-1-W, 125-128 cm 125-128 U1362A-9R-1-W,

Proc. IODP | Volume 327 14 Site U1362 core descriptions Thin sections droxides, celadonite y t. h y arallel to cataclastic zone. p Saponite replaces mesostasis and olivine iron oxyhydroxides replaces olivine and fills vesicles Celadonite replaces olivine and fills vesicles Sub- herical fill: iron ox Vesicle p s y straight euhedral Entirely pseudomorphed to iron oxyhydroxides or saponite hl g subhedral to SIZE(mm) SIZE(mm) THICKNESS(mm) plagioclaseGROUNDMASS plagioclaseolivinemesostasispyroxeneSECONDARY MINERALOGY saponite 3.4iron oxidesceladonite 31VESICLESMINERALOGY 0 traceceladonite, iron oxides 3.6 27 33 1 3 25.3 MODAL PERCENT 26 6 ABUNDANCE PERCENT 4 28 2 FILLED 1.6 min. 1.4 100 max. euhedral <0.2 mode Occurs singly 0.1 0.1 euhedral SHAPE 0.2 Skeletal laths and needles euhedral subhedral COMMENTS subhedral Pseudomorphed to saponite, iron oxyhydroxides or celadonite Occurs attached to/intergrown with plagioclase <0.4 hi THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 74-75 cm 327-U1362A-9R-2-W, zone (sheet flow) cataclastic PRIMARY sparsely (olivine) clinopyroxene plagioclase phyric microcrystalline basalt MINERALOGYPHENOCRYSTS pyroxene microcrystalline Piece No: 10 m/gm: spherulitic, intersertal; phen: seriate olivine PRESENT Unit: 4A PERCENT ORIGINAL PERCENT THIN SECTION 18 JR, OBSERVER: min. 0.5 max. trace mode MORPHOLOGY 1 COMMENTS 2 0.3 0.4 0.7 0.7 0.4 0.5 subhedral SUMMARY DESCRIPTIONSUMMARY Description based on lithology adjacent to cataclastic zone. Characterized by matrix of ground up host basal VEINS FILLING SHAPE COMMENTS U1362A-9R-2-W, 74-75 cm 74-75 U1362A-9R-2-W,

Proc. IODP | Volume 327 15 Site U1362 core descriptions Thin sections eladonite + saponite rich) - orange grey . g resence of alteration halo p vesicles within area of alteration halo (split into iron oxyhydroxides rich and (orange alteration halo band): saponite - iron oxyhydroxides lining, celadonite iron oxyhydroxides + saponite mix. Vesicle fill (background alteration): saponite iron oxyhydroxides + saponite mix. Vesicle linin oxyhydroxides, celadonite + saponite mix, celadonite, saponite. Vesicle fill oxyhydroxides, celadonite + saponite mix, celadonite, saponite. Vesicle Celadonite and iron oxyhydroxides replacing mesostasis, olivine filling Variably replaced by saponite, iron oxyhydroxides or celadonite depending on Variably Attached to/intergrown with plagioclase Saponite replacing mesostasis, olivine and filling vesicles thoughout Oxides replacing mesostasis, olivine and filling vesicles thoughout COMMENTS COMMENTS Vesicle fill (green alteration halo band): celadonite - saponite iron Vesicle euhedral spherical moderately anhedral to SIZE(mm) SIZE(mm) THICKNESS(mm) 20 40 0.2 1.8 0.8 (saponite only). Alteration halo is split into bands: orange (predominatly iron oxyhydroxides replacement of vesicles and mesostasis) - green (c THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 37-40 cm 327-U1362A-11R-1-W, alteration halo (sheet flow interior) multilayered PRIMARY aphyric fine-grained basalt MINERALOGYPHENOCRYSTS plagioclase grained fine GROUNDMASS Piece No: 6 subophitic, vesicular intersertal to intergranular, plagioclasemesostasisolivine PRESENT PERCENT Unit: 4Cpyroxene ORIGINAL PERCENT THIN SECTION 19 JR, OBSERVER: <2 min. 33 max. 2 mode <2 trace MORPHOLOGY COMMENTS 21 36 0.9 10 0.1 8 1.6 26VEINSN/A 0.9 <0.1 0.9 DESCRIPTION SUMMARY <0.1 0.8 0.2 subhedral 0.3 Stubby laths partially altered to saponite + celadonite mix euhedral 0.2 Laths, partially altered by oxides and saponite 0.3 Completely altered to saponite + iron oxyhydroxides mix FILLING SHAPE SECONDARY MINERALOGY saponiteoxidesiron oxidesceladoniteVESICLESMINERALOGYsaponite, celadonite, iron 10 MODAL PERCENT 2 ABUNDANCE 1 PERCENT 3 FILLED min. max. mode SHAPE oxides U1362A-11R-1-W, 37-40cm

Proc. IODP | Volume 327 16 Site U1362 core descriptions Thin sections ix replacing mesostasis, respectively. ix replacing mesostasis, respectively. onite p Saponite and oxides filling vein replacing mesostasis throughout. COMMENTS COMMENTS One main saponite and oxide filled vein that steps around rarely cuts across Two vesicles. Vesicle fill: iron oxyhydroxides lining with saponite + celadonite mix vesicles. Vesicle Two core, sa Saponite, iron oxyhydroxides and celadonite filling vesicles. celadonite + saponite mix. Celadonite fills microvein. vein for part of the thin section. This crosscuts crystals and is composed of vein for part of the thin section. crystals. A discontinuous microvein (<0.1 mm thick) runs parallel to the larger A crystals. herical p s moderately SIZE(mm) SIZE(mm) THICKNESS(mm) 0.1 100 0.8 PERCENT MODALPERCENT PERCENT Vein runs parallel with the alteration halo boundary, implying some association. runs parallel with the alteration halo boundary, Vein Multilayer halo of orange, green and grey bands. Green orange bands defined by celadonite saponite iron oxyhydroxides m THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 125-129 cm 327-U1362A-12R-1-W, pillow interior (alteration halo) PRIMARY moderately plagioclase clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS olivine microcrystalline Piece No: 10plagioclase subophitic, seriate intersertal to intergranular, GROUNDMASS plagioclaseolivine Unit: 5Apyroxene PRESENT PERCENTmesostasisSECONDARY ORIGINALTHIN SECTION 20 OBSERVER:JR, PERCENT MINERALOGY iron oxides min.saponite 1 traceoxidesceladonite max. 40 trace mode 37VESICLES 1 0.5 MORPHOLOGY COMMENTS 1 41 <0.1 VEINS 0.7 12 38 12 1 19 0.1 <0.1 1.2 ABUNDANCE 2 <0.1 <0.1 1.7 DESCRIPTION SUMMARY 0.8 FILLED 0.7 0.2 0.7 1.2 0.8 min. subhedral <0.2 0.5 completely altered to saponite and celadonite Occurs singly, max. euhedral euhedral subhedral Skeletal crystals and laths, occasionally in glomeroporphyritic clots Laths and needles mode FILLING SHAPE opaques Includes SHAPE saponite, celadonite, iron celadonite, saponite, oxides mixed 0.1 irregular oxides U1362A-12R-1-W, 125-129 cm 125-129 U1362A-12R-1-W,

Proc. IODP | Volume 327 17 Site U1362 core descriptions Thin sections ass. reen alteration halo. itself at one end; sidesteps vesicles but crosscuts crystals; roughly divides light g Saponite replacing mesostasis, groundmass and filling vesicles vein iron oxyhydroxides filling vesicles within light grey alteration halo and vein Oxides filling vesicles within light grey alteration halo and vein Celadonite replacing groundmass and filling vesicles within area of dark grey- COMMENTS Some vesicles have coalesced into irregular shaped, filled and unfilled vugs. COMMENTS anastomoses and doubles back on Fibrous saponite core where present. Vein brown-red iron oxyhydroxides, oxyhydroxides lining with saponite core, core, textured iron oxyhydroxides + oxide + saponite mix. Vesicle fill (dark grey core, textured iron oxyhydroxides + oxide saponite mix. Vesicle Vesicle and vug fill (light grey alteration halo): bright orange iron oxyhydroxides, Vesicle saponite + iron oxyhydroxides mix, celadonite lining with alteration halo): celadonite + saponite mix, iron oxyhydroxides and dark grey alteration halos. SIZE(mm) SIZE(mm) THICKNESS(mm) mixed 0.1 irregular 1.7 98 0.2 6.5 0.4 slightly spherical PERCENT MODALPERCENT PERCENT THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 41-43 cm 327-U1362A-13R-1-W, pillow interior (vugs) PRIMARY moderately clinopyroxene plagioclase phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS plagioclase cryptocrystalline pyroxene Piece No: 7 intersertal, glomeroporphyritic spherulitic, GROUNDMASS pyroxeneplagioclasemesostasis PRESENT PERCENT Unit: 5ASECONDARY ORIGINALMINERALOGY PERCENT saponiteTHIN SECTION 21 OBSERVER:JR, 6.2 min.celadonite 0.2iron oxides max.oxides 7 18 10 mode 6.3 MORPHOLOGY COMMENTS 0.3 0.9 21 10 51 60 0.4 3 2 2 <0.1 <0.1VEINS 0.9 1 1.5 0.2 0.1 0.4 DESCRIPTIONSUMMARY euhedral <0.1 0.1 Patchy background alteration is defined by intense patches of saponite replacement mesostasis and groundm euhedral Laths and skeletal crystals Stubby laths anhedral euhedral Laths and needles FILLING Mostly replaced by saponite SHAPE VESICLES ABUNDANCE FILLED min. max. mode SHAPE saponite, celadonite, iron 5% saponite, 98% iron oxides oxides U1362A-13R-1-W, 41-43cm

Proc. IODP | Volume 327 18 Site U1362 core descriptions Thin sections Vesicle fill: saponite, saponite lining Vesicle COMMENTS COMMENTS Saponite and iron oxyhydroxides mix replaces mesostasis fills vesicles Saponite and iron oxyhydroxides mix replaces mesostasis fills vesicles herical p s y htl g SIZE(mm) SIZE(mm) THICKNESS(mm) PERCENT MODALPERCENT PERCENT onite 2 90 0.2 1.3 0.5 sli p sa THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 60-62 cm 327-U1362A-14R-1-W, pillow interior PRIMARY highly clinopyroxene plagioclase phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS plagioclase cryptocrystalline GROUNDMASS Piece No: 8 to variolitic, intersertal spherulitic plagioclaseolivinemesostasis PRESENTSECONDARY PERCENT Unit: 5BMINERALOGY saponite ORIGINAL PERCENT THIN SECTION 22 JR, OBSERVER: 3 min. 10 max. 0 0 modeVEINS 3N/A MORPHOLOGY COMMENTS 10 DESCRIPTIONSUMMARY 76 Mesostasis largely altered to saponite, defines patchy background alteration. 80 0.6 5 <0.1 1.8 0.2 <0.1 0.7 <0.2 0.1 euhedral euhedral <0.1 Laths; occur singly and in unconnected clusters Needles, often forming nuclei for aggregates of radiating fibrous crystals FILLING anhedral Entirely altered to saponite Completely altered to saponite/clay SHAPE iron oxides 10 VESICLES ABUNDANCE FILLED min. max. mode SHAPE U1362A-14R-1-W, 60-62cm

Proc. IODP | Volume 327 19 Site U1362 core descriptions Thin sections roxene and olivine Saponite replacing mesostasis and olivine Laths and skeletal crystals. occurs singly as glomeroporphyritic clots with py THICKNESS(mm) SIZE(mm) SIZE(mm) PERCENT MODALPERCENT PERCENT pyroxeneolivineGROUNDMASS plagioclasepyroxenemesostasisolivineSECONDARY MINERALOGY oxides 0.5saponite 21 0 16 5 0.5 trace 21 2 0.3 16 50 <1 55 0.1 8 0.7 0.4 <0.1 0.8 0.4 1 0.1 0.2 0.3 euhedral <0.1 0.3 0.4 Occurs as glomeroporphyritic clots with plagioclase and olivine euhedral anhedral 0.3 0.3 Needles and laths. Form spherulitic splays in patches of mesostasis anhedral anhedral Rounded, entirely altered to saponite Mostly altered to saponite. patchy distribution VESICLESN/A VEINSN/A DESCRIPTIONSUMMARY Patchy background alteration defined by larger areas of mesostasis that are entirely altered to saponite. ABUNDANCE FILLED min. max. mode FILLING SHAPE COMMENTS SHAPE COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 45-47 cm 327-U1362A-15R-1-W, pillow interior PRIMARY highly clinopyroxene plagioclase phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS cryptocrystalline plagioclase intersertal, glomeroporphyritic, subophitic Piece No: 10 PRESENT Unit: 5B PERCENT ORIGINAL PERCENT THIN SECTION 23 JR, OBSERVER: min. 2.8 max. mode 2.8 MORPHOLOGY COMMENTS 0.8 1.6 0.8 euhedral U1362A-15R-1-W, 45-47cm

Proc. IODP | Volume 327 20 Site U1362 core descriptions Thin sections onite + iron oxyhydroxides opaque reservation. p reservation. p layered celadonite (olive green) - iron oxyhydroxides saponite; lining Moderate with iron oxyhydroxides core; celadonite (partially overprinted by saponite); saponite mix with iron oxyhydroxides lining and core, later Present as glomeroporphyritic clots associated with plagioclase laths. High occurs singly and occasionally in monomineralic glomeroporhyritic clots. Occurs attached to/intergrown with plagioclase Completely replaced by saponite, oxides and celadonite COMMENTS COMMENTS Vesicle fill: 13 filled, 22 partially filled. Filled vesicles: iron oxyhydroxides + Vesicle saponite - carbonate (imaged). Unfilled vesicles: celadonite (olivine green) iron celadonite - iron oxyhydroxides nodular overgrowths into vesicle core fibrous alteration of entire vesicle has resulted in broken concentric 'worm' like separation of fill (imaged); iron oxyhydroxides with pale brown saponite core; anhedral spherical subhedral moderately anhedral to euhedral to SIZE(mm) SIZE(mm) THICKNESS(mm) 15 30 1.1 3.4 3 PERCENT MODALPERCENT PERCENT (hematite or geothite). Saponite, celadonite and opaques uniformly present in groundmass. Secondary mineral phases the vesicles are + sap THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 89-91 cm 327-U1362A-16R-3-W, flow interior (green alteration halo) sheet PRIMARY sparsely clinopyroxene plagioclase phyric microcrystalline basalt MINERALOGYPHENOCRYSTS microcrystalline pyroxene Piece No: 5plagioclaseGROUNDMASS plagioclase PRESENT PERCENT Unit: 6Apyroxene ORIGINAL PERCENT THIN SECTION 24 JR, OBSERVER: min. 1.6 max. 3.9 35 mode MORPHOLOGY COMMENTS 2 23 7 2.2 1.4 5.5 0.1 4.1 5.5 0.1VEINS 3.2 3.6N/A 3.2 1.3 subhedral DESCRIPTION SUMMARY 1.8 euhedral Laths and needles FILLING SHAPE mesostasisSECONDARY MINERALOGY saponiteceladoniteiron oxidesoxidescarbonates 21 saponite, celadonite, iron 5 5 2 trace 3 VESICLES ABUNDANCE FILLED min. max. mode SHAPE oxides, carbonate U1362A-16R-3-W, 89-91cm

Proc. IODP | Volume 327 21 Site U1362 core descriptions Thin sections atches. p atches. p ence, unlike the irridescent nature of carbonate. g birefrin within area of alteration vein. Replacing mesostasis, groundmass and olivine filling vesicles Filling vesicles 0.5 anhydrite Occurs attached to/intergrown with plagioclase. Partially repaced by saponite Vesicle fill: saponite, saponite - + oxide mix Vesicle Laths and skeletal crystals. Partially repaced by saponite within area of alteration Partially replaced by saponite, more intense alteration in isolated patches and COMMENTS COMMENTS Fibrous material displaying bright, and in places, uniform 4th+ order halo and alteration within alteration halo and herical p euhedral s moderately subhedral to 0.2 irregular SIZE(mm) SIZE(mm) Piece No: 3 Unit: 6BTHIN SECTION 25 JR, OBSERVER: THICKNESS(mm) PERCENT MODALPERCENT PERCENT 327-U1362A-18R-2-W, 100-102 cm 327-U1362A-18R-2-W, onite, oxides 1.5 100 <0.2 1 0.9 p oxidescarbonateanhydrite <0.1 3 0.5 THIN SECTION: pyroxeneopaque mineralsolivinemesostasisSECONDARY MINERALOGY saponite 3 24VESICLES 0 8 3 28VEINS 25 anhydrite <0.1 21 2 DESCRIPTIONSUMMARY ABUNDANCE Pale alteration halo defined by replacement of groundmass and mesostasis saponite. 0.4 <0.1 FILLED <0.4 0.2 min. 0.2 max. <0.2 euhedral mode anhedral Completely replaced by saponite/oxides FILLING SHAPE SHAPE ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: flow interior (vein) sheet PRIMARY sparsely clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS plagioclase microcrystalline pyroxene intergranular to intersertal subophitic, olivineGROUNDMASS plagioclase PRESENT PERCENT ORIGINAL PERCENT min. 3 3 max. 0 29 mode 3 MORPHOLOGY COMMENTS 3 1 1.1 34 0.3 1.7 0.3 0.1 0.6 1.3 0.5 0.9 0.5 euhedral 0.3 <0.6 euhedral Laths occuring singly and in monomineralic glomeroporphyritic clots Occurs as solitary crystals euhedral anhedral Occurs as solitary crystals. completely pseudomorphed by saponite sa U1362A-18R-2-W, 100-102 cm 100-102 U1362A-18R-2-W,

Proc. IODP | Volume 327 22 Site U1362 core descriptions Thin sections onite altered mesostasis. p onite, sa p , sa g roundmass and fills vesicles within alteration halo. g onite linin laces p p : sa ) celadonite mix, iron oxyhydroxides and saponite mix. Vesicle fill (background celadonite mix, iron oxyhydroxides and saponite mix. Vesicle alteration Saponite replaces mesostasis and fills vesicles iron oxyhydroxides replace groundmass and fill vesicles within alteration halo Celadonite re COMMENTS fill (alteration halo): iron oxyhydroxides, oxyhydroxides and Vesicle COMMENTS SIZE(mm) SIZE(mm) THICKNESS(mm) 6.3 70 <0.2 0.9 0.8 highly spherical PERCENT MODALPERCENT PERCENT oxidesiron oxidesceladonite 6 1 2 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 78-80 cm 327-U1362A-18R-5-W, flow interior (orange alteration halo) sheet PRIMARY sparsely clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS olivine microcrystalline plagioclase Piece No: 4 intersertal to hyalophitic, phen: glomerophorphyritic m/gm: pyroxeneGROUNDMASS plagioclaseolivine PRESENT PERCENTpyroxene Unit: 6Bmesostasis ORIGINAL PERCENT SECONDARY THIN SECTION 26 JR, OBSERVER: MINERALOGY min. 8.5saponite trace 1.5 max. 40 mode trace 8.5 3.1 24 MORPHOLOGY COMMENTS 9 1.8 41 0.6 0.7VEINS 2 7 0.2 25N/A 15 <0.1 1.6 0.8 DESCRIPTIONSUMMARY 0.7 Alteration halo defined by iron oxyhydroxides replacement of mesostasis and fills vesicles. <0.1 <0.1 0.7 0.9 0.7 0.3 0.1 0.2 <0.5 euhedral anhedral subhedral Occurs singly and in monomineralic glomeroporphyritic clots entirely pseudomorphed by saponite <0.1 Occurs singly. <0.2 euhedral Occurs singly. Laths subhedral subhedral Entirely pseudomorphed by saponite Occurs singly or attached to/intergrown with plagioclase FILLING SHAPE VESICLES ABUNDANCE FILLED min. max. mode SHAPE saponite, celadonite, iron oxides U1362A-18R-5-W, 78-80cm

Proc. IODP | Volume 327 23 Site U1362 core descriptions Thin sections y with carbonate core. g onite linin p laces mesostasis and fills vesicles within alteration halo onl p onite, carbonate, sa p sa Carbonate fills two vesicles outside of alteration halo Saponite replaces mesostasis and fills vesicles Vesicle fill (alteration halo): celadonite. Vesicle fill (background alteration): fill (alteration halo): celadonite. Vesicle Vesicle Celadonite re COMMENTS COMMENTS herical p s moderately SIZE(mm) SIZE(mm) THICKNESS(mm) 0.6 70 <0.1 1.3 <0.1 PERCENT MODALPERCENT PERCENT Carbonate fills vesicles outside of alteration halo. Halo defined by celadonite filled vesicles. saponiteoxides 72 1 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 13-16 cm 327-U1362A-19R-1-W, basalt flow (patchy background alteration) PRIMARY sparsely plagioclase phyric microcrystalline basalt MINERALOGYPHENOCRYSTS plagioclase microcrystalline olivine Piece No: 3 hyalophitic GROUNDMASS plagioclasemesostasis PRESENTSECONDARY PERCENT Unit: 7AMINERALOGY celadonite ORIGINAL PERCENT carbonateTHIN SECTION 27 JR, OBSERVER: 2.3 min. trace max. 13VESICLES 7 mode 2.5 MORPHOLOGY COMMENTS 0.5VEINS 3 N/A 21 0.5 1 75.4 DESCRIPTION SUMMARY 0.2 ABUNDANCE <0.1 2.2 FILLED 0.3 0.9 1 min. 0.2 <0.3 euhedral max. anhedral euhedral Occurs singly and in glomeroporphyritic clots olivine mode Pseudomorphed by saponite Skeletal laths and needles FILLING SHAPE SHAPE saponite, celadonite, carbonate U1362A-19R-1-W, 13-16cm

Proc. IODP | Volume 327 24 Site U1362 core descriptions Thin sections ing of vesicles. saponite core; lining; saponite; celadonite lining with iron oxyhydroxides COMMENTS COMMENTS Vesicle fill: celadonite lining, iron oxyhydroxides, saponite; lining with Vesicle core. herical p s moderately SIZE(mm) SIZE(mm) THICKNESS(mm) 15 95 0.1 0.7 0.5 PERCENT MODALPERCENT PERCENT saponite, celadonite, iron THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 31-34 cm 327-U1362A-19R-2-W, basalt flow PRIMARY highly clinopyroxene plagioclase phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS plagioclase cryptocrystalline pyroxene Piece No: 7 variolitic to hyalophitic, phen: glomeroporphyritic m/gm: GROUNDMASS mesostasisplagioclasepyroxene PRESENT PERCENT Unit: 7BSECONDARY MINERALOGY ORIGINAL PERCENT N/A THIN SECTION 28 JR, OBSERVER: 13 min.VESICLES max. 4 1.5 mode 14.6 2.5VEINS MORPHOLOGY COMMENTS N/A 0.4 64 DESCRIPTIONSUMMARY ABUNDANCE 3 Alteration halo defined by replacement of mesostasis (saponite, celadonite, and iron oxyhydroxides) fill 3 1.2 FILLED 0.1 min. 0.4 0.2 max. euhedral <0.2 Occurs singly and in glomeroporphyritic clots with clinopyroxene mode subhedral <0.2 SHAPE Occurs singly and in glomeroporphyritic clots with plagioclase FILLING 0.1 euhedral Laths and needles subhedral altered to define. To SHAPE oxides U1362A-19R-2-W, 31-34cm

Proc. IODP | Volume 327 25 Site U1362 core descriptions Thin sections roxene and/or olivine py ritic clots with clino y h ioclase p g or la p p lomero g ritic clots with y and as h y l p g or p lomero g fill (background alteration): saponite lining, mesostasis, saponite. Compeltely pseudomorphed by saponite. Occurs singly and occasionally in Occurs sin COMMENTS fill (alteration halo association): celadonite lining with saponite core, Vesicle COMMENTS Celadonite fills vesicles and replaces mesostasis within area of alteration halo Saponite replaces mesostasis, groundmass and fills vesicles mesostasis lining with celadonite core, saponite-celadonite mix, saponite. Vesicle mesostasis lining with celadonite core, saponite-celadonite mix, saponite. Vesicle SIZE(mm) SIZE(mm) THICKNESS(mm) 16 65 0.2 5 0.7 highly spherical PERCENT MODALPERCENT PERCENT saponite, celadonite, THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 70-72 cm 327-U1362A-20R-2-W, basalt flow interior (alteration halo) PRIMARY highly clinopyroxene plagioclase phyric cryptocrystalline basalt MINERALOGYPHENOCRYSTS cryptocrystalline olivine Piece No: 11 hyalophitic, variolitic to intersertal, phen: glomeroporphyritic subophitic m/gm: plagioclasepyroxeneGROUNDMASS pyroxene PRESENT Unit: 7B PERCENTplagioclasemesostasis ORIGINAL PERCENT SECONDARY THIN SECTION 29 JR, OBSERVER: MINERALOGY min.celadonite 24 trace max. 8 mode 8 14 MORPHOLOGY 4 COMMENTS 20.6 0 9VEINS 0.4 5 15N/A 9 0.2 26 DESCRIPTIONSUMMARY 0.3 Alteration halo is defined by replacement of mesostasis and filling vesicles. No associated vein present 4 0.7 <0.1 <0.1 0.6 1.2 0.5 0.3 0.1 0.4 euhedral <0.3 subhedral <0.1 euhedral euhedral subhedral Occurs singly and occasionally in glomeroporphyritic clots with plagioclase Laths and needles Occurs single or attached to/intergrown with plagioclase FILLING SHAPE saponiteoxidesVESICLES 24 ABUNDANCE 1 FILLED min. max. mode SHAPE mesostasis U1362A-20R-2-W, 70-72cm

Proc. IODP | Volume 327 26 Site U1362 core descriptions Thin sections onite p onite core, sa p lanes and fractures. with sa p g e g cleava g droxides linin y h y ioclase alon g , iron ox g la p lace p onite linin p droxides re y h y saponite core. Vein crosscuts phenocryst and groundmass crystals. Associated crosscuts phenocryst and groundmass crystals. saponite core. Vein vein from saponite to iron oxyhydroxides lining with Iron oxyhydroxides replace mesostasis and fills vesicle vein Saponite replaces mesostasis and fills vesicles vein Occurs singly and in glomerporphyritic clots with clinopyroxene. Iron COMMENTS COMMENTS Three subparallel and interconnected irregular veins. Composition varies along vesicles are iron oxyhydroxides filled. ox fill: sa Vesicle y SIZE(mm) SIZE(mm) THICKNESS(mm) Piece No: 16 Unit: 8THIN SECTION 30 JR, OBSERVER: PERCENT MODALPERCENT PERCENT 327-U1362A-21R-1-W, 104-106 cm 327-U1362A-21R-1-W, onite, iron oxides 4.1 30 <0.2 0.8 0.8 moderatel p VESICLES ABUNDANCE FILLED min. max. mode SHAPE THIN SECTION: pyroxeneGROUNDMASS plagioclasemesostasisSECONDARY MINERALOGY iron oxides 4 5 0VEINS 4.1 25 saponite, iron oxides 5 61 0.2 DESCRIPTIONSUMMARY branched vein and microvein network filled with iron oxyhydroxides saponite. A 1.1 0.3 subeuhedral mixed Occurs in glomerporphyritic clots with plagioclase. <0.4 FILLING euhedral Occurs as skeletal laths or needles 0.1 branched SHAPE oxidessaponite 2 42 ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: basalt flow PRIMARY sparsely plagioclase clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS olivine microcrystalline hyalophitic, variolitic, phen: glomeroporphyritic m/gm: plagioclase PRESENT PERCENT ORIGINAL PERCENT min. trace 25 max. mode 2.6 MORPHOLOGY COMMENTS 27.3 <0.4 0.4 0.6 3 0.5 1.2 subhedral Pseudomorphed by saponite euhedral sa U1362A-21R-1-W, 104-106 cm 104-106 U1362A-21R-1-W,

Proc. IODP | Volume 327 27 Site U1362 core descriptions Thin sections stals. y stals y roundmass cr g ioclase cr g la p es filled vesicles. Groundmass outside of roundmass g droxides mix. Vein crosscuts droxides mix. Vein y h y mix. Vesicle fill (background alteration): saponite. mix. Vesicle celadonite vein crosscuts oxyhydroxides core, celadonite lining with iron - saponite iron oxyhydroxides to celadonite lining, core celadonite. Celadonite replaces mesostasis and fills vesicles in area of alteration halo COMMENTS fill (green alteration halo): celadonite lining, saponite lining with iron Vesicle COMMENTS Composition changes along vein from pink saponite-iron oxyhydroxides mix to Composition changes along vein from orange saponite-iron oxyhydroxides mix to Saponite replaces mesostasis, fills vesicles and vein Iron oxyhydroxides fill vesicles in area of alteration halo and fils vein Some associated groundmass crystals are entirely replaced by celadonite and fills vein. celadonite-iron ox celadonite lining with iron oxyhydroxides core, and SIZE(mm) SIZE(mm) THICKNESS(mm) mixedmixed <0.1 0.1 irregular irregular 5.9 95 0.2 0.8 0.7 highly spherical PERCENT MODALPERCENT PERCENT Two veins filled with celadonite, saponite and iron oxyhydroxides. Alteration halo is defined by celadonite and ron oxyhydroxid veins filled with celadonite, saponite and iron oxyhydroxides. Two alteration halo area is stained pink by iron oxyhydroxides and saponite replacement. ioclase g la p saponite, celadonite, iron saponite, celadonite, iron saponite, celadonite, iron THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE: TEXTURE: 71-73 cm 327-U1362A-21R-2-W, flow (red background alteration) sheet PRIMARY sparsely plagioclase clinopyroxene phyric microcrystalline basalt MINERALOGYPHENOCRYSTS plagioclaseGROUNDMASS Piece No: 8 hyalophitic, phen: subophitic m/gm: plagioclasepyroxenemesostasis PRESENTSECONDARY PERCENT Unit: 8MINERALOGY saponite ORIGINAL PERCENT 4.5THIN SECTION 31 JR, OBSERVER: min.iron oxides 48 max. 18 3 mode 5.3 MORPHOLOGY COMMENTS 48 19 18 1 23 VEINS 3 <0.1 2.4 <0.1 0.6 0.2 1.2 <0.4 DESCRIPTION SUMMARY <0.1 euhedral euhedral Occurs singly and in glomeroporphyritic clots subhedral Laths Occurs attached to/intergrown with plagioclase FILLING SHAPE celadoniteoxides 4 2 VESICLES ABUNDANCE FILLED min. max. mode SHAPE oxides oxides oxides, U1362A-21R-2-W, 71-73cm

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