Site U1374 core descriptions Thin sections "euhedral to subhedral" "euhedral to subhedral" replaced by iddingsite (hematite?) palagonite vesicle anhedral anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS glassaugiteplagioclaseSECONDARY MINERALOGY calcite STRUCTURECOMMENTS 68 9 1 DESCRIPTION SUMMARY no structure in groundmass 100 0.2 0.01 microlite[330] MICROPHENOCRYST plagioclaseolivineaugiteVESICLESGROUNDMASSopaque mineralolivine 0.01 4 87 3 5 1 40 4 95 0.3 0.4 0.1 0.9 1.8 0.4 laths[330] 0.6 0.3 0.3 skeletal 0.09 0.06 subhedral subhedral to low[330] just 2 grains 100 filled by calcite incomplete dome face (iddingsite); "skeletal olivine" & sector-zoning titanaugite THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 114 114-SLIDE 114_116-BILLET 330-U1374A-3R-1-W clast type 2 PRIMARY olivine-phyric basalt clast moderately MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric moderately Unit:I ORIGINAL PERCENT REPLACED 10 REL. VOL. 5 20 min. SIZE(mm) max. mode. SECTION:SLIDE 114 OBSERVER:THIN MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 8 VESICLE 1.2 VESICLE skeletal incomplete dome face (iddingsite); "skeletal olivine" & Site U1374 thin sections U1374A-3R-1-W 114_116

Proc. IODP | Volume 330 1 Site U1374 core descriptions Thin sections altered by iddingsite altered to clay vesicle anhedral[330] anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 115 115-SLIDE 7_9-BILLET 330-U1374A-3R-2-W TYPE 1 CLAST PRIMARY basalt clast highly olivine-phyric MINERALOGYPHENOCRYSTS grained fine No: Piece olivineMICROPHENOCRYST highly phyric & glomeroporphyritic olivineaugite ORIGINAL PERCENT REPLACEDplagioclase Unit:I 17 REL. VOL.VESICLESGROUNDMASSaugiteolivine 11opaque mineralplagioclase 3glass 1 2 79 50 4SECONDARY MINERALOGY 80calcite min. SIZE(mm) 4 1 max.STRUCTURE 3 mode.COMMENTS 7 MORPHOLOGY SECTION:SLIDE 115 OBSERVER:THIN 100 DESCRIPTIONSUMMARY 64 SPHERICITY fresh olivine phenocryst weak trachytic texture in groundmass Infilling [%] COMMENTS 100 6 VESICLE 2 0.9 0.02 VESICLE 0.6 0.3 1 0.4 0.2 0.3 0.3 skeletal subhedral subhedral to 0.06 0.1 laths[330] 0.05 0.05 0.3 subhedral to 0.2 anhedral laths[330] low[330] altered by iddingsite & clay; "olivine; euhedral to subhedral" 100 filled by calcite ( "very angular; round") U1374A-3R-2-W 7_9

Proc. IODP | Volume 330 2 Site U1374 core descriptions Thin sections Altered to green clay. high[330] 100 brown clay and calcite vesicle vesicle euhedral subhedral some altered to iddingsite REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. olivine 5 40 6 2 subhedral (chlorite?) alteration along cracks. Green clay GROUNDMASSolivineplagioclase oxidesFe-Ti glass 88 42 3 1 10 42 80 0 100 0.3 0.1 0.1 0.3 0.05 0.04 laths[330] THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 116 116-SLIDE 53_55-BILLET 330-U1374A-3R-2-W 1 in sedimentary unit TYPE CLAST PRIMARY clast highly olivine-plagiclase-phyric basalt MINERALOGYPHENOCRYSTS Piece No: fine grained augite porphyritic plagioclaseMICROPHENOCRYST ORIGINALolivine PERCENT Unit:4 REPLACEDVESICLES 11 REL. VOL. 5 0.5 1 1 0 min. SIZE(mm) 80 max. mode. SECTION:SLIDE 116 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 1.5 0.2 6.4 0.2 VESICLE 1 0.4 0.4 0.3 0.2 euhedral euhedral subhedral some are broken oscillatory zoning and clay) some altered to iddingsite (carbonate MINERALOGY brown clay calcite STRUCTURECOMMENTS DESCRIPTIONSUMMARY highly olivine-plagioclase-phyric basalt clast in sediment no structure in groundmass SECONDARY U1374A-3R-2-W 53_55

Proc. IODP | Volume 330 3 Site U1374 core descriptions Thin sections altered vesicle vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 118 118-SLIDE 108_110-BILLET 330-U1374A-3R-2-W of unit 1 representative PRIMARY basalt highly olivine-plagioclase-augite-phyric MINERALOGY No: Piece PHENOCRYSTS grained fine olivine oxideFe-Ti highly phyric plagioclaseaugite Unit:1 ORIGINALMICROPHENOCRYST PERCENT REPLACED oxideFe-Ti 20 REL. VOL.plagioclaseolivineVESICLESGROUNDMASS 0.5olivine 9 2 oxidesFe-Ti plagioclaseglass 1 1 10 3SECONDARY 79 MINERALOGY 1 4.5clay min. 0 SIZE(mm)calcite max. 14 mode.STRUCTURE 5 30 SECTION:SLIDE 118 OBSERVER:THIN 50COMMENTS MORPHOLOGY 30 SPHERICITY DESCRIPTIONSUMMARY 50 Infilling [%] phenocrysts; strained olivine phenocrysts Laths flowing around COMMENTS no structure in groundmass 65 3 8 VESICLE 1.2 3 2 VESICLE 1 3 0.1 0.5 1 0.5 anhedral subhedral 0.8 subhedral 1 0.5 0.2 1 euhedral 0.3 subhedral 0.3 subhedral 0.02 0.3 0.05 0.15 subhedral anhedral laths[330] medium + carbonate some strained; replaced by clays/chlorite zoned 100 one with horneblende inclusion clay. filled with calcite & green altered by clay aligned flow around phenocrysts U1374A-3R-2-W 108_110

Proc. IODP | Volume 330 4 Site U1374 core descriptions Thin sections altered by iddingsite elongated[EXP330] clay). vesicle vesicle anhedral altered by iddingsite. laths[330] inclined subhedral to anhedral[330] REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. plagioclaseVESICLESGROUNDMASSplagioclaseglassopaque minerals 1 2SECONDARY 95 MINERALOGY calcite zeolite 60 6 STRUCTURECOMMENTS 27 DESCRIPTIONSUMMARY 100 Pl laths flowing around phenocrysts structures at the rim (brown are only along alteration zone; carbonate-filled vein with botryoidal Vesicles 0.06 1.6 0.5 0.3 0.2 laths[330] 0.08 low and 100 and calcite (in the middle). vesicles filled with zeolite inclined THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 119 119-SLIDE 38_41-BILLET 330-U1374A-4R-2-W 2 representative of UNIT PRIMARY aphyric basalt MINERALOGYPHENOCRYSTS Piece No: fine grained MICROPHENOCRYST olivine aphyric ORIGINAL PERCENT Unit:2 REPLACED REL. VOL. 3 2 100 min. SIZE(mm) max. mode. SECTION:SLIDE 119 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.4 VESICLE 0.2 VESICLE olivine 2 100 0.1 0.07 U1374A-4R-2-W 38_41

Proc. IODP | Volume 330 5 Site U1374 core descriptions Thin sections palagonite at the rim. vesicle vesicle anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS GROUNDMASSopaque mineralplagioclaseolivineglass 97 7 60 1 29 100 100 0.08 0.02 0.2 0.1 0.08 subhedral 0.02 laths[330] anhedral inclined altered by clay. THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 120 120-SLIDE 137_139-BILLET 330-U1374A-5R-2-W patch 2; one more vesicular of UNIT representative PRIMARY basalt aphyric MINERALOGY Piece No:PHENOCRYSTS grained fine MICROPHENOCRYST olivine aphyric VESICLES Unit:2 ORIGINAL PERCENT REPLACED REL. VOL. 2 SECONDARY 2 1MINERALOGY zeolite calcite 100STRUCTURECOMMENTS min. SIZE(mm) max. mode. DESCRIPTIONSUMMARY SECTION:SLIDE 120 OBSERVER:THIN Just freshest part of the thinsection is described here. MORPHOLOGY bands of aligned Pl laths, weak trachytic texture SPHERICITY Infilling [%] COMMENTS 0.1 0.6 VESICLE 0.2 0.3 0.1 VESICLE subhedral to low[330] 100 filled with carbonate and zeolite in the middle + fibrous clay U1374A-5R-2-W 137_139

Proc. IODP | Volume 330 6 Site U1374 core descriptions Thin sections completely altered by iddingsite & hematite. completely altered by iddingsite elongated[EXP330] vesicle laths[330] inclined anhedral[330] subhedral to anhedral replaced by iddingsite SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS VESICLESplagioclaseSECONDARY 4MINERALOGY calcite STRUCTURECOMMENTS 3 DESCRIPTIONSUMMARY Width of calcite vein: 0.8mm. bands of aligned Pl laths, weak trachytic texture 0.7 11 0.08 0.04 laths[330] low and 100 filled with calcite and a few well-crystallized zeolites. inclined olivine 4 100 0.5 0.3 subhedral to THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 123-SLIDE 123 114_116-BILLET 330-U1374A-6R-1-W clast in volcanic breccia PRIMARY aphyric basalt clast MINERALOGY Piece No:PHENOCRYSTS fine grained MICROPHENOCRYST plagioclase aphyric Unit:3 ORIGINAL PERCENT REPLACED 10 REL. VOL. 6 min. SIZE(mm) max. mode. SECTION:SLIDE 123 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.6 VESICLE 0.2 VESICLE GROUNDMASSglass 86 81 100 olivine 2 100 0.09 0.01 U1374A-6R-1-W

Proc. IODP | Volume 330 7 Site U1374 core descriptions Thin sections altered to brown & green clay. vesicle anhedral by clay. replaced REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. THIN SECTION:ROCK NAME:WHERE SAMPLED: GRAINSIZE:TEXTURE: 124 124-SLIDE 136_138-BILLET 330-U1374A-7R-1-W PRIMARY aphyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained MICROPHENOCRYST aphyric olivineplagioclase Unit:4 ORIGINALVESICLES PERCENT REPLACED 5.5 REL. VOL. 3 2 1 100 min. SIZE(mm) max. mode. SECTION:SLIDE 124 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.2 VESICLE 0.2 0.9 2 VESICLE 0.1 0.7 0.3 anhedral laths[330] low[330] 100 and green clay (nontronite) filled with calcite & brown inclined plagioclasecalcite STRUCTURECOMMENTS 15 DESCRIPTION SUMMARY bands of aligned Pl laths, weak trachytic texture 0.1 0.06 inclined microlites[330] plagioclaseGROUNDMASSglass 0.5 94.5 76 100 1.4 1.2 laths[330] inclined opaque mineralSECONDARY MINERALOGY 3 0.02 0.01 olivine 0.5 100 0.01 U1374A-7R-1-W 136_138

Proc. IODP | Volume 330 8 Site U1374 core descriptions Thin sections particles; in rock matrix; altered; palagonized sandy particles; in rock matrix; altered; palagonized palagonized sandy in groundmass of clasts; altered; SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS 5 0.3 2 0.5 low[330] 5 palagonite on rims THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 126 126-SLIDE 112_114-BILLET 330-U1374A-7R-4-W sand of lithic-vitric volcanic representative PRIMARY vitric aphyric[EXP330] basalt sand palagonitized MINERALOGY Piece No:PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric Unit:7 ORIGINAL PERCENT REPLACED REL. VOL. 0 olivineplagioclaseplagioclaseglass 5 20 0.5 13 min. SIZE(mm) max. 100 5 mode. SECTION:SLIDE 126 OBSERVER:THIN MORPHOLOGY 100 SPHERICITY Infilling [%] COMMENTS 0.2 2.4 VESICLE 0.4 VESICLE 0.2 0.4 0.05 0.4 0.1 0.1 anhedral laths[330] low[330] laths[330] 25calcite filling "void space in matrix" -- in clasts; few in groundmass; altered to iddingsite; and aphyric basalt clasts; laths in sandy groundmass laths in sandy groundmass and aphyric basalt clasts; GROUNDMASS oxideFe-Ti glass 20 1 39 50 0.1 0.1 anhedral in groundmass of clasts olivinepyroxene oxideFe-Ti SECONDARY MINERALOGY STRUCTURECOMMENTS 0.5 0.5 5 DESCRIPTIONSUMMARY glass & aphyric basalt clast Photo: Palagonized No structure in groundmass 100 0.1 0.05 0.2 0.1 0.05 0.1 anhedral anhedral anhedral few in groundmass of clasts; altered to iddingsite; in groundmass of clasts in matrix U1374A-7R-4-W 112_114

Proc. IODP | Volume 330 9 Site U1374 core descriptions Thin sections Altered glass. moderate[EXP330] vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS plagioclaseSECONDARY MINERALOGY calcite STRUCTURECOMMENTS 5.5 DESCRIPTION SUMMARY No structure in groundmass 0.2 0.1 laths[330] THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 132 132-SLIDE 24_28-BILLET 330-U1374A-9R-1-W clast breccia Volcanic PRIMARY moderately olivine-phyric basalt clast MINERALOGYPHENOCRYSTS Piece No: fine grained plagioclase sparsely phyric MICROPHENOCRYST plagioclase ORIGINALolivine PERCENT Unit:8 REPLACEDVESICLES 5.5 REL. VOL.GROUNDMASSolivine 0.5glass 2 70 25 1 69.5 50 min. SIZE(mm) 100 max. 2 mode. 62 SECTION:SLIDE 132 OBSERVER:THIN MORPHOLOGY 100 SPHERICITY 100 [%] Infilling COMMENTS 4.2 2.1 0.04 VESICLE 0.9 10 VESICLE 0.7 0.9 laths[330] 0.4 0.4 laths[330] 0.05 subhedral 0.02 subhedral to anhedral low to 100 clay Mainly filled by calcite and altered by iddingsite and clay Altered by iddingsite olivine 2 100 2.8 2.6 subhedral altered by iddingsite and clay U1374A-9R-1-W 24_28

Proc. IODP | Volume 330 10 Site U1374 core descriptions Thin sections elongated[EXP330] vesicle laths[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS VESICLES 3 0.06 10 0.4 low and 100 Filled by calcite olivineSECONDARY MINERALOGY calcite STRUCTURECOMMENTS DESCRIPTION SUMMARY 3 No structure in groundmass; irregular arbonate-filled vein. 100 0.1 0.04 subhedral to anhedral Iddingsite. THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 133 133-SLIDE 25_29-BILLET 330-U1374A-9R-4-W clast breccia Volcanic PRIMARY moderately olivine-phyric basalt clast MINERALOGYPHENOCRYSTS Piece No: fine grained olivineplagioclase moderately phyric MICROPHENOCRYST olivine ORIGINALplagioclase PERCENT Unit:8 REPLACED REL. VOL. 8 GROUNDMASSglass 0.5 3 1.5 30 3 100 89 20 100 min. SIZE(mm) max. 78 mode. SECTION:SLIDE 133 OBSERVER:THIN MORPHOLOGY 100 SPHERICITY [%] Infilling COMMENTS 1.3 3.6 1.2 VESICLE 2 0.9 0.9 VESICLE 0.4 laths[330] 0.6 subhedral laths[330] subhedral clay altered by iddingsite and brown subhedral to anhedral altered by iddingsite ("brown clay") plagioclase 8 0.1 0.05 U1374A-9R-4-W 25_29

Proc. IODP | Volume 330 11 Site U1374 core descriptions Thin sections vesicle brown clay also contains anhedral by iddingsite altered SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS augiteopaque mineralsSECONDARY MINERALOGY calcite STRUCTURE 4COMMENTS 3 DESCRIPTION SUMMARY No structure in groundmass 0 0.1 0.05 0.04 usually needle shaped 0.02 anhedral THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 135-SLIDE 135 115_119-BILLET 330-U1374A-12R-4-W TYPE 3 Sedimentary breccia; CLAST PRIMARY aphyric basalt No: Piece MINERALOGYPHENOCRYSTS fine grained MICROPHENOCRYST aphyric & poorly glomeroporphyritic plagioclaseaugite Unit:IX ORIGINALolivine PERCENT REPLACEDVESICLES 3.1 REL. VOL.GROUNDMASSglass 1 96 2 0.9 0.05 0 100 53 min. 0 SIZE(mm) max. mode. SECTION:SLIDE 135 OBSERVER:THIN 100 MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.3 VESICLE 0.7 0.5 0.3 0.6 VESICLE 0.8 0.3 0.4 0.5 laths[330] subhedral subhedral high[330] 100 filled by carbonate and brown clay altered by brown clay olivineplagioclaseolivine 0.05 100 30 6 0 100 1.6 subhedral 0.3 0.2 0.1 0.08 laths[330] clay altered by carbonate and brown U1374A-12R-4-W 115_119

Proc. IODP | Volume 330 12 Site U1374 core descriptions Thin sections low[330] 100 vesicle laths[330] anhedral[330] subhedral to anhedral SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS MINERALOGY calcite MICROPHENOCRYST plagioclase 3 10 0.9 0.5 olivineaugiteGROUNDMASSglassolivineplagioclase 3SECONDARY 86 1 95STRUCTURECOMMENTS 0 60 20 5 DESCRIPTION SUMMARY 100 No structure in groundmass 5 100 0.9 0.2 0.4 0.3 skeletal, prismatic subhedral to 0.4 0.1 0.06 0.2 subhedral to anhedral laths[330] altered by iddingsite THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE:136 136-SLIDE 3_5-BILLET 330-U1374A-13R-1-W TYPE 3 Sedimentary breccia CLAST PRIMARY aphyric basalt MINERALOGYPHENOCRYSTS No: Piece fine grained aphyric ORIGINAL PERCENT REPLACED Unit:IX REL. VOL. 7 min. SIZE(mm) max. mode. SECTION:SLIDE 136 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE VESICLE VESICLES 7 0.1 0.8 0.4 augite 1 0 0.08 0.05 U1374A-13R-1-W 3_5

Proc. IODP | Volume 330 13 Site U1374 core descriptions Thin sections anhedral altered to iddingsite; skeletal; subhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. STRUCTURECOMMENTS DESCRIPTION SUMMARY calcite vein, bands of aligned pl laths, weak trachytic texture plagioclaseVESICLESGROUNDMASSglass 1 98 0.5 0 13 100 0.16 0.26 0.7 0.2 0.7 laths[330] moderate[330] 0 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 141-SLIDE 141 125_127-BILLET 330-U1374A-16R-1-W representative of unit 9 PRIMARY aphyric basalt No: Piece MINERALOGYPHENOCRYSTS fine grained aphyric Unit:9 ORIGINAL PERCENT REPLACED 1.5 REL. VOL. min. SIZE(mm) max. mode. SECTION:SLIDE 141 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE VESICLE olivineaugiteSECONDARY MINERALOGY 10 15 90 0.4 0.1 anhedral skeletal; altered to iddingsite; plagioclase oxideFe-Ti 50 10 0 0 0.4 0.1 0.1 0.05 laths[330] alignment of laths MICROPHENOCRYST olivine 0.5 85 0.5 0.5 U1374A-16R-1-W 125_127

Proc. IODP | Volume 330 14 Site U1374 core descriptions Thin sections high[330] 30 smectite & calcite eing the top of the section) REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. MICROPHENOCRYST VESICLES 0.5 0.1 0.6 0.2 MINERALOGY THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 143 143-SLIDE 65_67-BILLET 330-U1374A-17R-1-W clast breccia Volcanic PRIMARY aphyric basalt MINERALOGY No: Piece PHENOCRYSTS fine grained aphyric & sometimes subophitic ORIGINAL Unit:10 PERCENT REPLACED REL. VOL. 0 min. SIZE(mm) max. mode. SECTION:SLIDE 143 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE VESICLE GROUNDMASSolivineopaque mineralsplagioclaseglassSECONDARY 99.5 4STRUCTURECOMMENTS 6 60 DESCRIPTION SUMMARY 0 29.5 degrees (with 0 degrees b laths. Flow direction towards ~110-120 trachytic texture defined by aligned plagioclase Weak 90 0 100 0.1 0.02 0.9 0.6 0.2 0.2 subhedral to anhedral laths[330] altered by iddingsite. skeletal shaped inclined U1374A-17R-1-W 65_67

Proc. IODP | Volume 330 15 Site U1374 core descriptions Thin sections vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 145 145-SLIDE 31_33-BILLET 330-U1374A-18R-1-W clast breccia Volcanic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric GROUNDMASSplagioclase ORIGINALolivine Unit:10 PERCENT REPLACEDglass REL. VOL. 0 opaque mineralsSECONDARY 99.5 MINERALOGY 0.5zeolite 13STRUCTURE 5COMMENTS 7 72.5 0 DESCRIPTIONSUMMARY 0 Carbonate vein. min. SIZE(mm)vein/fracture; partly carbonate filling. No structure in groundmass; conjugate, sigmoidal 100 99 max. mode. SECTION:SLIDE 145 OBSERVER:THIN MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.1 4.5 0.2 VESICLE 0.6 VESICLE 0.2 0.1 0.6 0.02 0.1 laths[330] subhedral to anhedral high[330] 100 zeolite altered by iddingsite. skeletal; completely inclined U1374A-18R-1-W 31_33

Proc. IODP | Volume 330 16 Site U1374 core descriptions Thin sections laths[330] trachytic SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS MICROPHENOCRYST GROUNDMASSplagioclase 100 35 0 0.3 0.1 opaque mineralsolivineglass 4 0 2 59 100 100 0.1 0.01 anhedral THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 146 146-SLIDE 23_25-BILLET 330-U1374A-18R-3-W Lava lobe PRIMARY aphyric basalt MINERALOGY No: Piece PHENOCRYSTS fine grained aphyric ORIGINAL Unit:11 PERCENT REPLACED REL. VOL. 0 min. SIZE(mm) max. mode. SECTION:SLIDE 146 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE VESICLE MINERALOGY STRUCTURECOMMENTS DESCRIPTION SUMMARY texture Trachytic SECONDARY U1374A-18R-3-W 23_25

Proc. IODP | Volume 330 17 Site U1374 core descriptions Thin sections no vesicle altered part of thin section fresh part of thin section vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS 9 0.1 2 0.7 low and 100 volcanic clast vesicles only in altered glassy part of THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 147 147-SLIDE 50_53-BILLET 330-U1374A-19R-1-W of volcanic clast part Altered PRIMARY basalt MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric ORIGINAL Unit:12 PERCENT REPLACED REL. VOL. 0 olivineopaque mineralsglass 9 SECONDARY MINERALOGY calcite 2STRUCTURECOMMENTS 9 min. SIZE(mm) DESCRIPTIONSUMMARY 63 max. a clast with fresh glass; fossils in matrix. 1/5th of the slide has mode. texture in clast, no structure in groundmass Trachytic 70 SECTION:SLIDE 147 OBSERVER:THIN MORPHOLOGY 5 SPHERICITY Infilling [%] COMMENTS VESICLE VESICLE 0.2 0.04 0.3 0.02 subhedral skeletal altered by iddingsite GROUNDMASSplagioclaseglass fresh part of volcanic clast) (only in altered glassy part of volcanic clast) | 100: no vesicle (in 91: vesicles 25 55 0 90 0.4 0.2 laths[330] U1374A-19R-1-W 50_53

Proc. IODP | Volume 330 18 Site U1374 core descriptions Thin sections skeletal altered by iddingsite REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. glassSTRUCTURECOMMENTS DESCRIPTION SUMMARY 65 in groundmass weak trachytic texture 100 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 148 148-SLIDE 41_43-BILLET 330-U1374A-19R-2-W volcanic breccia clast PRIMARY aphyric basalt MINERALOGY No: Piece PHENOCRYSTS fine grained MICROPHENOCRYST GROUNDMASS aphyric olivine ORIGINAL Unit:12 PERCENT REPLACED REL. VOL. 0 100 5 80 min. SIZE(mm) max. mode. SECTION:SLIDE 148 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 0.9 VESICLE 0.1 plagioclaseSECONDARY MINERALOGY 30 0 0.9 0.1 laths[330] trachytic texture U1374A-19R-2-W 41_43

Proc. IODP | Volume 330 19 Site U1374 core descriptions Thin sections some of the freshest parts observed in left bottom of the thin some of the freshest parts observed section. SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 149 149-SLIDE 23_25-BILLET 330-U1374A-21R-2-W lava lobe PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST GROUNDMASS aphyric plagioclaseglass ORIGINAL Unit:13 PERCENT REPLACED REL. VOL. 0 100 45 49 0 95 min. SIZE(mm) max. mode. SECTION:SLIDE 149 OBSERVER:THIN MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.9 VESICLE 0.3 VESICLE laths[330] inclined olivineSECONDARY MINERALOGY STRUCTURECOMMENTS DESCRIPTIONSUMMARY 6 (3 mm in width/size) Carbonate-filled vein trachytic flow texture; sigmoidal carbonate vein. 100 1.2 0.2 skeletal inclined U1374A-21R-2-W 23_25

Proc. IODP | Volume 330 20 Site U1374 core descriptions Thin sections glass in lower-left part of TS. glass in lower-left part of palagonized clast and some fresh clast occurs; minor fresh palagonized clast and some vesicle zeolite minor SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS SECONDARY MINERALOGY carbonate STRUCTURECOMMENTS DESCRIPTIONSUMMARY Palagonized parts & rims. Some fresh glass occurs as a clast. No structure in groundmass THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 150 150-SLIDE 19_21-BILLET 330-U1374A-21R-3-W carbonate. basalt clasts are cemented by clast; glassy; aphyric breccia volcanic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric GROUNDMASSplagioclase ORIGINALolivine Unit:14 PERCENT REPLACEDglass REL. VOL. 0 99 1 20 5 74 0 min. SIZE(mm) 100 100 max. mode. SECTION:SLIDE 150 OBSERVER:THIN MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.2 0.5 VESICLE 0.4 0.6 VESICLE 0.3 0.4 0.1 laths[330] skeletal high[330] 100 Carbonate, minor zeolite; altered by iddingsite U1374A-21R-3-W 19_21

Proc. IODP | Volume 330 21 Site U1374 core descriptions Thin sections altered to iddingsite and clay anhedral[330] subhedral[330] subhedral[330] subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 156 156-SLIDE 49_51-BILLET 330-U1374A-22R-4-W TYPE 1 XI, CLAST Sedimentary UNIT PRIMARY plagioclase-augite-phyric[EXP330] basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine clinopyroxene moderately phyric plagioclase ORIGINALolivine Unit:XI PERCENT REPLACEDMICROPHENOCRYST 12 REL. VOL.opaque minerals 0.5plagioclaseolivine 3 0clinopyroxene 2VESICLES 1 0GROUNDMASSclinopyroxene 3olivine 0 min. SIZE(mm)opaque minerals 98glass max. 0.1 mode.plagioclase 3 SECTION:SLIDE 156 OBSERVER:THIN 0 MORPHOLOGY 80 SECONDARY 7MINERALOGY 0 SPHERICITY 5 98 15 Infilling [%]STRUCTURE COMMENTS COMMENTS 1 30 DESCRIPTION SUMMARY 2.6 30 1.5 No structure in groundmass 100 VESICLE 2.9 100 euhedral to 1.5 VESICLE 0.3 3.6 0.1 euhedral to 2 0.8 subhedral to 0.4 0.8 subhedral 0.9 0.05 0.4 euhedral to 0.5 1.2 0.5 euhedral to 0.06 euhedral to 0.05 0.03 0.02 0.05 0.02 subhedral 0.2 subhedral 0.08 subhedral altered to iddingsite and carbonate/calcite moderate[330] laths[330] 100 iddingsite U1374A-22R-4-W 49_51

Proc. IODP | Volume 330 22 Site U1374 core descriptions Thin sections moderately fresh iddingsite anhedral subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 157 157-SLIDE 27_29-BILLET 330-U1374A-24R-1-W breccia volcanic PRIMARY basalt highly olivine-plagioclase-pyroxene-phyric MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseaugite highly phyric olivine ORIGINALMICROPHENOCRYST Unit:16 PERCENT REPLACEDolivine 25 REL. VOL.augiteplagioclase 4GROUNDMASSglassolivine 2plagioclase 7 5SECONDARY MINERALOGY 6 0 75 30 5STRUCTURE 1 min. SIZE(mm)COMMENTS max. 50 mode. 51 23 SECTION:SLIDE 157 OBSERVER:THIN 5 DESCRIPTION SUMMARY 1 0 MORPHOLOGY No structure in groundmass SPHERICITY 100 0 Infilling [%] 100 COMMENTS 5 VESICLE 1.4 3 6.5 VESICLE 1.3 2 tabular 0.9 0.4 0.9 subhedral euhedral to 0.9 0.6 0.3 euhedral to 0.2 0.1 tabular subhedral microlites sometimes sieve texture; (c-zoning) clots, sieve texture U1374A-24R-1-W 27_29

Proc. IODP | Volume 330 23 Site U1374 core descriptions Thin sections altered to iddingsite and minor carbonate altered to iddingsite and minor altered to iddingsite anhedral laths[330] euhedral[330] euhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 158 158-SLIDE 77_80-BILLET 330-U1374A-24R-1-W Lava flow fragment PRIMARY basalt highly olivine-plagioclase-pyroxene-phyric[EXP330] MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseolivine highly phyric augite ORIGINALMICROPHENOCRYST Unit:18 PERCENT REPLACEDolivine 21 REL. VOL.augiteplagioclase 4GROUNDMASSplagioclaseopaque minerals 5olivine 5glass 3SECONDARY 4 95 79 MINERALOGY 3 2 min. 0 SIZE(mm) 15STRUCTURE 20COMMENTS max. 95 mode. SECTION:SLIDE 158 OBSERVER:THIN 5 0 MORPHOLOGY 0 0.5 DESCRIPTION SUMMARY 0 43.5 SPHERICITY vein (0.2 mm). No structure in groundmass; small carbonate Infilling [%] 100 COMMENTS 100 5 VESICLE 1.2 3 VESICLE 2 5.2 sieve texture 2.5 0.9 0.4 to subhedral 0.9 0.9 0.05 0.6 subhedral 0.01 0.7 subhedral to sieve texture subhedral U1374A-24R-1-W 77_80

Proc. IODP | Volume 330 24 Site U1374 core descriptions Thin sections altered to iddingsite, green clay and some carbonate altered to iddingsite, green clay subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 159 159-SLIDE 34_36-BILLET 330-U1374A-24R-4-W Lave flow fragment PRIMARY phyric basalt highly olivine-plagioclase-augite MINERALOGY No: Piece PHENOCRYSTS grained fine augiteolivine highly phyric plagioclase ORIGINALMICROPHENOCRYST Unit:20 PERCENT REPLACEDaugite 24 REL. VOL.olivineplagioclaseGROUNDMASSglass 2olivine 8 6plagioclaseSECONDARY 0MINERALOGY 50 1 76 5 3 4STRUCTURE min. SIZE(mm)COMMENTS max. 0 mode. 100 71 SECTION:SLIDE 159 OBSERVER:THIN 4 5 DESCRIPTION SUMMARY 1 MORPHOLOGY No structure in groundmass SPHERICITY 100 0 Infilling [%] 100 COMMENTS VESICLE 3 6 4 2.2 VESICLE 1.2 1.6 0.9 0.9 subhedral sieve texture[330] euhedral to 0.9 0.6 0.5 0.6 euhedral to subhedral sieve texture[330] 0.04 0.1 0.01 0.01 anhedral small laths tabular; microcline; tabular; microcline; U1374A-24R-4-W 34_36

Proc. IODP | Volume 330 25 Site U1374 core descriptions Thin sections altered to iddingsite altered to iddingsite elongated[EXP330] laths laths are small vesicle with green clay (saponite?) also filled anhedral euhedral to subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS MICROPHENOCRYST plagioclaseaugiteolivineVESICLESGROUNDMASSolivine 5plagioclase 1 4 1 5 75 0 100 9 2 0 100 0.9 0.2 0.6 0.9 0.9 1.2 sieve texture[330] 0.6 0.6 0.8 subhedral tabular; centered-zoning. low and 100 filled with carbonate & green clay (saponite) THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 160-SLIDE 160 100_102-BILLET 330-U1374A-24R-4-W Lava flow fragment PRIMARY basalt highly olivine-plagioclase-pyroxene-phyric[EXP330] No: Piece MINERALOGYPHENOCRYSTS fine grained augiteplagioclase highly phyric olivine Unit:22 ORIGINAL PERCENT REPLACED 24 REL. VOL. 4 3 7 5 0 100 min. SIZE(mm) max. SECTION:SLIDE 160 OBSERVER:THIN mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 6 VESICLE 2 1.6 3 1.4 VESICLE 1.5 sieve texture[330] subhedral euhedral to tabular; centered-zoning. STRUCTURECOMMENTS DESCRIPTION SUMMARY No structure in groundmass glass 64 100 SECONDARY MINERALOGY carbonate U1374A-24R-4-W 100_102

Proc. IODP | Volume 330 26 Site U1374 core descriptions Thin sections altered high[330] 100 filled by calcite anhedral altered to iddingsite. inclusions; SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS olivine 3 100 0.9 0.6 plagioclaseVESICLESGROUNDMASSglassopaque mineralsolivinefeldsparSECONDARY 4 81 MINERALOGY 0.5 1STRUCTURECOMMENTS 0 55 DESCRIPTIONSUMMARY 0 5 20 Photo: Inclusions in feldspar. No structure in groundmass; carbonate vein (0.12 mm) 100 100 0 0.5 0.8 0.9 0.8 0.6 0.2 0.1 laths[330] 0.1 0.1 0.05 anhedral 0.1 anhedral laths[330] contain inclusions; mostly crystallized altered to iddingsite THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 161-SLIDE 161 112_115-BILLET 330-U1374A-25R-1-W 24 representative of UNIT PRIMARY basalt highly plagioclase-olivine-augite phyric No: Piece MINERALOGYPHENOCRYSTS fine grained augite moderately phyric plagioclaseMICROPHENOCRYST Unit:24 ORIGINALaugite PERCENT REPLACED 18.5 REL. VOL. 5 1 0.5 0 0 min. SIZE(mm) 0 max. SECTION:SLIDE 161 OBSERVER:THIN mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 2 2 VESICLE 1.2 1.1 0.7 0.6 laths[330] subhedral contain inclusions, mostly crystallized olivine 5 80 3.2 1.5 subhedral contain inclusions; crystallized; altered to iddingsite. U1374A-25R-1-W 112_115

Proc. IODP | Volume 330 27 Site U1374 core descriptions Thin sections iddingsite iddingsite altered melt inclusions euhedral[330] euhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 162 162-SLIDE 84_86-BILLET 330-U1374A-25R-2-W fragment lava flow or PRIMARY olivine-plagioclase-augite basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric moderately plagioclase ORIGINALpyroxene Unit:26 PERCENT REPLACEDMICROPHENOCRYST 18 REL. VOL.olivinepyroxeneplagioclaseVESICLES 3 2GROUNDMASSglassplagioclase 1 100 oxideFe-Ti 0olivine 5SECONDARY 2 min. 0 SIZE(mm) 5 80 MINERALOGY 0.5 max. mode.STRUCTURE 90 SECTION:SLIDE 162 OBSERVER:THIN COMMENTS 25 0 MORPHOLOGY 0 50 5 SPHERICITY DESCRIPTIONSUMMARY Infilling [%] 20 and zeolite (at the rim); vein filled with calcite 0 COMMENTS vein No structure in groundmass; irregular 100 0 100 3.8 VESICLE 9 1 VESICLE 1.8 1.2 to subhedral 1 0.2 0.8 subhedral 0.4 1.8 1 1 subhedral 0.4 0.5 0.5 subhedral to 0.15 0.1 0.02 subhedral subhedral 0.005 0.1 subhedral to anhedral 0.05 laths[330] subhedral moderate[330] Some crystals contain sieve texture, some zonation, or fresh some zonation; melt inclusions; sieve texture; altered to iddingsite U1374A-25R-2-W 84_86

Proc. IODP | Volume 330 28 Site U1374 core descriptions Thin sections and/or are resorbed. altered Oscillatory zonation. Some crystals have sieve texture Oscillatory zonation. Some crystals 75 calcite rounded[330] vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 163 163-SLIDE 128_131-BILLET 330-U1374A-25R-2-W 28 of UNIT representative PRIMARY plagioclase-olivine-augite-phyric basalt moderately No: Piece MINERALOGYPHENOCRYSTS grained fine olivineplagioclase moderately phyric Unit:28 ORIGINAL PERCENT REPLACED 16 REL. VOL. 4 3 0 80 min. SIZE(mm)SECONDARY MINERALOGY max. SECTION:SLIDE 163 OBSERVER:THIN mode.calcite MORPHOLOGYSTRUCTURECOMMENTS SPHERICITY Infilling [%] COMMENTS DESCRIPTIONSUMMARY Photos: PX + PLAG glomerocrysts; 3 carbonate veins No structure in groundmass; veins are straight to sigmoidal. 2.2 2 VESICLE 1.5 1.5 VESICLE euhedral laths[330] replaced by iddingsite contain inclusions; form glomerocrysts with augite. GROUNDMASSopaque mineralsaugiteplagioclaseolivineglass 83 1 25 0.5 0 9.5 47 0 0 100 100 0.1 0.05 0.1 0.2 0.07 anhedral 0.1 0.05 0.05 laths[330] anhedral subhedral glomerocryst with plagioclase altered to iddingsite augiteMICROPHENOCRYST augiteolivineplagioclaseVESICLES 1.5 0.5 3 2 1 0 0 0 90 1.3 0.05 1.1 0.8 0.9 0.1 0.9 0.5 0.08 0.6 0.7 subhedral anhedral laths[330] subhedral high and form glomerocrysts with plagioclase form glomerocrysts with plagioclase contain inclusions; form glomerocrysts with augite replaced by iddingsite U1374A-25R-2-W 128_131

Proc. IODP | Volume 330 29 Site U1374 core descriptions Thin sections and/or edge resorption. Some faint oscillatory zoning. and/or edge resorption. Some vesicle vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS olivineMICROPHENOCRYST olivineVESICLES 5 4 1 80 80 0.1 2.4 1.5 4 0.4 0.5 0.2 subhedral subhedral elongate[330] 100 Calcite fill. Some clay? iddingsite iddingsite MINERALOGY calcite clay STRUCTURECOMMENTS DESCRIPTIONSUMMARY Highly olivine-plagioclase-augite-phyric basalt Calcite vein, no structure in groundmass GROUNDMASSglass oxideFe-Ti plagioclaseSECONDARY 85 49 1 30 100 0 0 0.3 0.5 0.1 0.1 laths[330] THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 164-SLIDE 164 104_107-BILLET 330-U1374A-25R-3-W Lava lobe/fragment PRIMARY basalt highly olivine-plagioclase-augite-phyric[EXP330] No: Piece MINERALOGYPHENOCRYSTS fine grained augiteplagioclase highly phyric Unit:30 ORIGINAL PERCENT REPLACED 11 REL. VOL. 3 2 0 0 min. SIZE(mm) max. SECTION:SLIDE 164 OBSERVER:THIN mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 4 VESICLE 2 1 VESICLE 1 euhedral subhedral have sieve texture Some with inclusions. Some crystals olivine 5 100 0.1 0.05 subhedral iddingsite U1374A-25R-3-W 104_107

Proc. IODP | Volume 330 30 Site U1374 core descriptions Thin sections filled with carbonate. subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 166 166-SLIDE 49_51-BILLET 330-U1374A-27R-2-W fragment) and feldspar crystal of unit (lava lobe or representative PRIMARY basalt highly olivine-plagioclase-augite-phyric[EXP330] MINERALOGY No: Piece PHENOCRYSTS grained fine augiteplagioclase highly phyric olivine ORIGINALMICROPHENOCRYST Unit:31 PERCENT REPLACEDaugite 26 REL. VOL.olivineopaque minerals 7plagioclase 2GROUNDMASSolivine 8plagioclase 0glass 0 1 1SECONDARY 90 4MINERALOGY min. SIZE(mm) 74 3 max.STRUCTURE 0 0 mode. 100COMMENTS SECTION:SLIDE 166 OBSERVER:THIN MORPHOLOGY 4 1 0 DESCRIPTIONSUMMARY SPHERICITYAlso augite euhedral crystal with groundmass. Vein 69 with groundmass inclusion (11mm). Plagioclase megacrystal veins (0.16 mm) No structure in groundmass. Straight Infilling [%] COMMENTS 0 100 100 11 4.5 VESICLE 2 1.3 5.6 VESICLE 3 sieve texture[330] 0.5 subhedral 0.9 0.9 0.2 0.7 0.7 euhedral to 0.9 euhedral to euhedral to 0.7 subhedral 0.06 0.1 sieve texture[330] 0.02 0.04 centered-zonning anhedral small laths centered-zonning U1374A-27R-2-W 49_51

Proc. IODP | Volume 330 31 Site U1374 core descriptions Thin sections iddingsite iddingsite anhedral subhedral[330] subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 167 167-SLIDE 82_86-BILLET 330-U1374A-27R-2-W crystal in unit 31 feldspar PRIMARY basalt highly olivine-plagioclase-pyroxene-phyric[EXP330] MINERALOGY No: Piece PHENOCRYSTS grained fine augite glomeroporphyritic highly phyric & plagioclase-augite olivine plagioclase ORIGINALolivine Unit:31 PERCENT REPLACED 22 REL. VOL.MICROPHENOCRYST olivineolivine plagioclase 2augite 6GROUNDMASSolivine 6 0plagioclase 0glassopaque minerals 4 min. SIZE(mm) 100 3 max.SECONDARY mode. 78 MINERALOGY SECTION:SLIDE 167 OBSERVER:THIN 100 1 MORPHOLOGYSTRUCTURE 0COMMENTS 3 SPHERICITY 1 1 Infilling [%] COMMENTS 0 DESCRIPTIONSUMMARY 73 & clay. filled with carbonate (19 mm) with sieve texture. Vein Plagioclase megacrystal No structure in groundmass 0 100 0 100 2.6 VESICLE 1.2 19 VESICLE 1.2 2.4 1.4 euhedral to sieve texture[330] 0.9 0.6 euhedral to 0.9 0.7 euhedral to 0.9 sieve texture[330] 0.7 0.1 0.1 0.01 0.1 euhedral to small laths subhedral oscillatory zonation or melt inclusions in some crystals U1374A-27R-2-W 82_86

Proc. IODP | Volume 330 32 Site U1374 core descriptions Thin sections altered by iddingsite and brown clay altered by iddingsite and brown vesicle also filled with clay (saponite?); calcite euhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 169 169-SLIDE 17_19-BILLET 330-U1374A-29R-4-W Lave flow fragment PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine opaque mineralsolivine aphyric MICROPHENOCRYST olivine ORIGINAL Unit:36 PERCENT REPLACEDplagioclase 1.5 REL. VOL.VESICLES 0.01GROUNDMASSplagioclaseglassolivine 0 0.5 0.5SECONDARY 0.5 98.5 MINERALOGY 100 50calcite 100 40STRUCTURE 0 min. SIZE(mm)COMMENTS max. 52.5 mode. 6 0 SECTION:SLIDE 169 OBSERVER:THIN DESCRIPTION SUMMARY MORPHOLOGY 100 No structure in groundmass SPHERICITY 100 Infilling [%] COMMENTS 1.2 only 1 anhedral crystal 1.8 VESICLE 0.04 1 0.7 VESICLE 0.8 0.7 1.5 0.4 0.1 euhedral 0.2 euhedral to 0.1 laths[330] 0.1 0.01 small laths subhedral to high[330] 95 altered by iddingsite and brown clay part of thin section only in the upper Vesicles U1374A-29R-4-W 17_19

Proc. IODP | Volume 330 33 Site U1374 core descriptions Thin sections calcite & quartz filling veins & voids calcite & quartz filling veins & glassy margin fresh in places, also palagonitized glassy margin fresh in places, nclusions. subhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. olivine 2.5 75 0.9 0.5 anhedral altered to iddingsite & green clays. GROUNDMASSglass 87.9 78 66 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 170-SLIDE 170 107_110-BILLET 330-U1374A-29R-4-W representative of unit 38 PRIMARY glassy margin basalt with moderately plagioclase-phyric[EXP330] No: Piece MINERALOGYPHENOCRYSTS aphanitic plagioclase but one very large porphyritic, moderately phyric & few phenocrysts, MICROPHENOCRYST plagioclase Unit:38 ORIGINALopaque minerals PERCENT REPLACED 12.1 REL. VOL.VESICLES 8 0.1 1 0 0 0 0 min. SIZE(mm) max. SECTION:SLIDE 170 OBSERVER:THIN mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 10 0.1 VESICLE 10 0.9 0.1 VESICLE 0.2 lath being resorbed subhedral subhedral phenocryst no inclusions in large inside olivine phenocryst host inclusions and being resorbed plagioclaseSTRUCTURECOMMENTS 9 DESCRIPTIONSUMMARY with i Photos: Large feldspar crystals without inclusions; glassy margin; resorbed feldspar microphenocrysts No structure in groundmass 0 0.05 0.03 laths[330] opaques 1 0 0.1 0.05 olivine 0.5 100 1 1 subhedral altered to iddingsite & green clays. SECONDARY MINERALOGY U1374A-29R-4-W 107_110

Proc. IODP | Volume 330 34 Site U1374 core descriptions Thin sections with calcite VESICLE VESICLE altered) with spalling shards. Transition to matrix breccia. Globules of glassy areas with plagioclase to matrix Transition altered) with spalling shards. vesicle some filled with clay REPLACING/FILLING COMMENTS ) mm ( SIZE(mm) min. max. mode. 2 90 0.6 0.5 subhedral completely altered 94 laths & spalling shards. THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 171 171-SLIDE 80_82-BILLET 330-U1374A-29R-7-W breccia Edge of pillow/lava lobe in PRIMARY moderately olivine-phyric basalt pillow/lobe No: Piece fine grained moderately Unit:39 PERCENT REL. VOL. SIZE SECTION:SLIDE 171 OBSERVER:THIN VESICLES 1 0.1 1 0.8 low[330] 50 in 'breccia matrix' filled Some filled with clay (?). Vesicles calcite MINERALOGY glassolivine OxidesFe-Ti plagioclaseSECONDARY 1 50 3 40 100 0 90 0 0.05 0.05 0.05 0.15 0.05 0.1 subhedral laths[330] MINERALOGYPHENOCRYSTSolivineplagioclaseMICROPHENOCRYST olivine ORIGINAL REPLACED 4.5 0.5 1.5 0 100 min. max. mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 1.5 2 1 1.5 euhedral subhedral fresh. contains fresh melt inclusions completely altered plagioclase 0.5 0 0.6 0.5 euhedral to laths fresh GROUNDMASS STRUCTURECOMMENTS DESCRIPTIONSUMMARY Continuous glassy margin (completely Moderately olivine-phyric basalt clast in breccia of same composition. No structure in groundmass. Small straight veins (0.7 mm). U1374A-29R-7-W 80_82

Proc. IODP | Volume 330 35 Site U1374 core descriptions Thin sections altered by brown clay euhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 172 172-SLIDE 50_52-BILLET 330-U1374A-30R-1-W Lava fragment PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivineplagioclase phyric sparsely MICROPHENOCRYST olivine ORIGINAL Unit:40 PERCENT REPLACEDplagioclase 6.5 REL. VOL.GROUNDMASSplagioclaseglassolivine 0.01 1SECONDARY MINERALOGY 93.5 0 5 0.5STRUCTURE 80COMMENTS 10 90 0 min. SIZE(mm) DESCRIPTIONSUMMARY 79.5 max. 5 veins (1-2 mm width in size). There is some carbonate 0 mode. mm) No structure in groundmass. Conjugate veins (0.12 SECTION:SLIDE 172 OBSERVER:THIN 100 MORPHOLOGY 95 SPHERICITY Infilling [%] COMMENTS 1.2 1.9 VESICLE 1.4 VESICLE 0.9 0.9 sieve texture 0.3 0.8 euhedral 0.1 0.08 subhedral to anhedral 0.1 small laths 0.04 subhedral to anhedral 1 crystal altered by brown clay U1374A-30R-1-W 50_52

Proc. IODP | Volume 330 36 Site U1374 core descriptions Thin sections laths[330] subhedralsubhedral clay and iddingsite alteration in fracture and rim Brown REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 173 12_15-BILLET173-SLIDE 330-U1374A-30R-5-W Lava fragment PRIMARY basalt moderately olivine-plagioclase-phyric MINERALOGY Piece No:PHENOCRYSTS fine grained plagioclaseolivine moderately phyric augiteMICROPHENOCRYST ORIGINALplagioclase Unit:49 PERCENT REPLACED 11 REL. VOL. 1 2 0.01 2 0 20 0 0 min. SIZE(mm) max. mode. SECTION:SLIDE 173 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 2.3 1.4 VESICLE 3.2 2.2 1.6 VESICLE 0.9 tabular 0.5 euhedral subhedral tabular sieve texture, centered-zonning, dissolved rims Brown clay and iddingsite alteration in fracture and rim dissolved rims sieve texture, centered-zonning, GROUNDMASSopaque mineralsglassSECONDARY MINERALOGY 89 0.01STRUCTURECOMMENTS 0 DESCRIPTION SUMMARY 79 Moderate subvertical (~010-020 degrees) trachytic texture 100 0.2 0.05 olivine 6 20 0.9 0.3 plagioclase 10 0 0.2 0.08 U1374A-30R-5-W 12_15

Proc. IODP | Volume 330 37 Site U1374 core descriptions Thin sections altered to iddingsite and brown clay altered to iddingsite and brown altered to iddingsite subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 175 20_22-BILLET175-SLIDE 330-U1374A-31R-6-W lava lobe fragment PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine olivine aphyric MICROPHENOCRYST olivine ORIGINAL Unit:56 PERCENT REPLACEDplagioclase 1.5 REL. VOL.GROUNDMASSplagioclaseolivineglass 0.5opaque mineralsSECONDARY 98.5 0.5MINERALOGY 0.5 100STRUCTURE 10COMMENTS 100 4 0 min. SIZE(mm) 6 DESCRIPTION max.SUMMARY 78.5 0 mode. SECTION:SLIDE 175 OBSERVER:THIN No structure in groundmass 0 MORPHOLOGY 100 100 SPHERICITY Infilling [%] COMMENTS 1.2 1.1 VESICLE 0.8 VESICLE 0.7 0.7 euhedral to 0.4 0.2 euhedral to 0.1 0.02 0.1 0.01 laths[330] 0.01 small laths subhedral anhedral iddingsite U1374A-31R-6-W 20_22

Proc. IODP | Volume 330 38 Site U1374 core descriptions Thin sections gray clay along fractures euhedral[330] anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 3_5-BILLET176-SLIDE 176 330-U1374A-32R-4-W lave lobe fragment PRIMARY olivine-phyric basalt sparsely MINERALOGYPHENOCRYSTS Piece No: grained fine hornblendeplagioclase phyric sparsely olivine ORIGINALMICROPHENOCRYST PERCENT REPLACEDolivine Unit:58 REL. VOL. 2 GROUNDMASSplagioclase 0.1olivine 0.01opaque mineralsglass 1 0 0SECONDARY 98 MINERALOGY 1STRUCTURE 10 15 5COMMENTS min. SIZE(mm) max. 10 4 mode. DESCRIPTIONSUMMARY 0 0 74 replaced by magentite & pyroxene (0.9 mm in size). Single crystal of hornblende, SECTION:SLIDE 176 OBSERVER:THIN MORPHOLOGY being the up-arrow) trachytic texture towards ~280 degrees (0 degrees 90 SPHERICITY Infilling [%] 100 COMMENTS 1 1.2 1 VESICLE 2.8 VESICLE 1.6 euhedral anhedral 0.8 subhedral to 0.5 0.6 0.2 0.1 subhedral to 0.01 laths[330] anhedral single crystal single crystal U1374A-32R-4-W 3_5

Proc. IODP | Volume 330 39 Site U1374 core descriptions Thin sections sigmoidal. anhedral[330] euhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 177 82_84-BILLET177-SLIDE 330-U1374A-33R-1-W clast breccia volcanic PRIMARY olivine-phyric basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric moderately MICROPHENOCRYST olivine ORIGINAL Unit:59 PERCENT REPLACEDGROUNDMASS REL. VOL. 3 olivineplagioclasemagnetiteglass 2 97 SECONDARY MINERALOGY 1 99STRUCTURECOMMENTS 4 11 100 min. SIZE(mm) 2 DESCRIPTIONSUMMARY max. mode. Carbonate vein (1.5 mm thick). 100 80 0 SECTION:SLIDE 177 OBSERVER:THIN laths. But no orientation/way up arrow on thin section. Veins Strong trachytic texture defined by aligned plagioclase MORPHOLOGY 0 SPHERICITY 100 Infilling [%] COMMENTS 2.4 VESICLE 1.8 0.9 VESICLE 0.6 euhedral to 0.1 0.4 0.02 subhedral to 0.1 0.1 0.05 subhedral to small laths U1374A-33R-1-W 82_84

Proc. IODP | Volume 330 40 Site U1374 core descriptions Thin sections altered to iddingsite and brown clay in interior and rim altered to iddingsite and brown altered to iddingsite subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 178 12_14-BILLET178-SLIDE 330-U1374A-34R-1-W lava fragment PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseolivine phyric sparsely MICROPHENOCRYST ORIGINALolivine Unit:63 PERCENT REPLACED REL. VOL. 3 plagioclaseGROUNDMASSglass 0.5olivineplagioclase 1SECONDARY 0MINERALOGY 97 1 0.5STRUCTURE 80COMMENTS min. SIZE(mm) 70 0 78 13 DESCRIPTION SUMMARY max. 6 mode. SECTION:SLIDE 178 OBSERVER:THIN laths. But no way up arrow on thin section. trachytic flow texture defined by aligned plagioclase MORPHOLOGY 100 0 100 SPHERICITY Infilling [%] COMMENTS 2.3 1.2 VESICLE 2 VESICLE 1.6 anhedral 0.8 0.4 0.4 0.4 euhedral to 0.2 euhedral to 0.1 anhedral 0.01 0.1 subhedral to anhedral laths[330] dissolved rims. Melt inclusions dissolved rims inclined U1374A-34R-1-W 12_14

Proc. IODP | Volume 330 41 Site U1374 core descriptions Thin sections altered to iddingsite rims sometimes shows dissolved crystals are euhedral vesicle subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 179 63_65-BILLET179-SLIDE 330-U1374A-34R-2-W clast breccia volcanic PRIMARY olivine-phyric basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric moderately MICROPHENOCRYST olivine ORIGINAL Unit:64 PERCENT REPLACEDVESICLES REL. VOL. 3 GROUNDMASSolivineplagioclaseglassmagnetite 2 95 SECONDARY 1 2MINERALOGY 90calcite 22STRUCTURE 90 5 min. SIZE(mm)COMMENTS max. 1 68 mode. 0 SECTION:SLIDE 179 OBSERVER:THIN 100 DESCRIPTIONSUMMARY MORPHOLOGY in the lower part of the thin section. Some fresh glass horizontal trachytic texture in places in the lower part of the thin section. some fresh glass. Weak 90 0 SPHERICITY Infilling [%] COMMENTS 4 VESICLE 0.1 1.5 VESICLE 0.9 4 0.8 euhedral to 0.4 0.3 0.1 euhedral to 0.08 0.01 subhedral to anhedral 0.3 0.01 small laths moderate[330] 90 small are irregular, bimodal size distribution; large crystals U1374A-34R-2-W 63_65

Proc. IODP | Volume 330 42 Site U1374 core descriptions Thin sections vesicle subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 180 61_63-BILLET180-SLIDE 330-U1374A-35R-3-W Lava lobe PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric sparsely MICROPHENOCRYST olivine ORIGINALaugite Unit:65 PERCENT REPLACEDplagioclase 2.7 REL. VOL.opaque mineralsVESICLESGROUNDMASSolivineglass 1plagioclaseopaque minerals 0.5 0.5 0.5 0.2SECONDARY 50 97 MINERALOGY 0.3calcite 0 40 0 min. SIZE(mm) 0STRUCTURE 4 max.COMMENTS 6 35 mode. 52 SECTION:SLIDE 180 OBSERVER:THIN MORPHOLOGY DESCRIPTIONSUMMARY 100 0 carbonate veins! 0 SPHERICITY Non-oriented thin section texture in groundmass (Pl). Trachytic 100 Infilling [%] COMMENTS 2.2 VESICLE 1 0.8 0.8 0.2 VESICLE 0.6 0.4 0.8 0.4 0.5 0.8 euhedral to 0.4 0.4 subhedral anhedral anhedral 0.2 anhedral 0.2 0.2 0.05 0.02 0.1 anhedral subhedral laths[330] moderate[330] 100 calcite devitrified melt inclusions resorbed rims resorbed rims resorbed rims completely altered to iddingsite. inclined U1374A-35R-3-W 61_63

Proc. IODP | Volume 330 43 Site U1374 core descriptions Thin sections vesicle anhedral laths[330] REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. olivine 8 100 0.1 0.02 opaque mineralsglasscalcite 0.5STRUCTURECOMMENTS 0 DESCRIPTION SUMMARY 82 Cross-cutting carbonate veins (0.12 mm) texture in zones. Non-oriented thin section. Trachytic 100 0.5 0.2 anhedral THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 181 98_100-BILLET181-SLIDE 330-U1374A-36R-1-W lava lobe PRIMARY sparsely olivine-phyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained augite sparsely phyric MICROPHENOCRYST plagioclase ORIGINAL Unit:67olivine PERCENT REPLACEDVESICLES 2.2 REL. VOL.GROUNDMASSplagioclase 0.1 0.1 97.5 0.3 1 0 0 7 min. SIZE(mm) 95 max. mode. 0 SECTION:SLIDE 181 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.7 VESICLE 1.3 0.8 0.3 0.9 VESICLE 0.9 0.7 0.6 0.2 anhedral anhedral 0.1 subhedral moderate[330] 100 calcite resorbed rims resorbed rims brown clay partly altered to iddingsite and SECONDARY MINERALOGY olivine 1 90 2.3 1.6 euhedral partly altered to iddingsite and brown clay U1374A-36R-1-W 98_100

Proc. IODP | Volume 330 44 Site U1374 core descriptions Thin sections altered to brown clay and iddingsite subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 182 76_78-BILLET182-SLIDE 330-U1374A-36R-4-W lava lobe PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivineMICROPHENOCRYST & rarely aug-pl glomeroporphyritic phyric sparsely opaque mineralsolivine ORIGINAL Unit:71 PERCENT REPLACEDaugite REL. VOL. 3 plagioclaseGROUNDMASSglass 0.5plagioclase 1.3olivineSECONDARY 0MINERALOGY 1 60 97 0.1 0.1STRUCTURECOMMENTS 30 min. 30 SIZE(mm) 0 59 0 DESCRIPTION max.SUMMARY mode. 8 SECTION:SLIDE 182 OBSERVER:THIN degrees. Straight carbonate veins (0.3 mm) texture towards ~110 Trachytic 0 MORPHOLOGY 100 SPHERICITY 100 Infilling [%] COMMENTS 0.9 2.4 0.5 VESICLE 1.4 VESICLE 0.8 subhedral 0.8 euhedral 0.4 1.6 0.6 0.3 euhedral to 0.1 anhedral 0.1 0.01 anhedral laths[330] anhedral altered to brown clay and iddingsite resorbed rims resorbed rims U1374A-36R-4-W 76_78

Proc. IODP | Volume 330 45 Site U1374 core descriptions Thin sections some part some part moderately fresh, brown clay and iddingsite alteration in moderately fresh, brown clay euhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 183 20_22-BILLET183-SLIDE 330-U1374A-37R-3-W lava lobe (autobrecciated) PRIMARY olivine phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivine & sometimes aug-pl glomeroporphyric phyric sparsely opaque mineralsaugite ORIGINALMICROPHENOCRYST Unit:74 PERCENT REPLACEDolivine REL. VOL. 2 plagioclaseGROUNDMASS 0.01glass 1.2opaque mineralsolivine 0 0.1plagioclase 40 98 0.5SECONDARY 0.2MINERALOGY 0.5 0 min. SIZE(mm)STRUCTURE 5 max.COMMENTS 87.5 0 mode. 0 SECTION:SLIDE 183 OBSERVER:THIN 3 MORPHOLOGY 7 DESCRIPTION SUMMARY 100 SPHERICITY texture towards ~260 degrees. Trachytic Infilling [%] 10 COMMENTS 0 0.6 2.8 1.2 VESICLE 1.2 VESICLE anhedral 2 euhedral to 0.6 0.6 0.4 0.4 0.4 0.3 anhedral subhedral anhedral 0.1 subhedral 0.2 0.01 0.1 subhedral to laths[330] iddingsite alteration in moderately fresh, brown clay and U1374A-37R-3-W 20_22

Proc. IODP | Volume 330 46 Site U1374 core descriptions Thin sections inclusions sometimes resorbed rim, brown clay alteration. Melt sometimes resorbed rim, brown clay alteration sometimes resorbed rim, brown subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 184 86_88-BILLET184-SLIDE 330-U1374A-38R-3-W lava lobe PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivine phyric sparsely MICROPHENOCRYST olivine ORIGINAL Unit:78 PERCENT REPLACEDplagioclase 2.5 REL. VOL.opaque mineralsGROUNDMASSplagioclasemagnetiteolivine 1glass 0.3SECONDARY 1 0.2 97.5 MINERALOGY 30STRUCTURE 0 9COMMENTS 30 0 min. SIZE(mm) 2.5 max. mode. DESCRIPTION SUMMARY 6 SECTION:SLIDE 184 OBSERVER:THIN 0 80 MORPHOLOGY 0 degrees. moderate trachytic texture towards ~110 SPHERICITY 100 Infilling [%] 100 COMMENTS 2 VESICLE 1.2 0.4 VESICLE 0.9 0.8 0.3 0.4 0.6 euhedral to 0.2 subhedral euhedral to 0.1 anhedral 0.1 0.05 0.1 0.01 laths[330] anhedral resorbed rim. Melt inclusions iddingsite late stage U1374A-38R-3-W 86_88

Proc. IODP | Volume 330 47 Site U1374 core descriptions Thin sections vesicle with clay and calcite filled anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 185 66_68-BILLET185-SLIDE 330-U1374A-39R-2-W clast breccia volcanic PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivineMICROPHENOCRYST phyric sparsely opaque minerals ORIGINALolivine Unit:79 PERCENT REPLACEDVESICLES REL. VOL. 4 GROUNDMASSolivineplagioclase 0.5glass 1.5SECONDARY MINERALOGY 95.5 0calcite 0.5 99 2STRUCTURECOMMENTS 2 7 min. SIZE(mm) 100 DESCRIPTION max.SUMMARY 86.5 mode. SECTION:SLIDE 185 OBSERVER:THIN no structure in groundmass Plagioclase microlites follow the outline of the phenocrysts; 0 100 MORPHOLOGY 0 SPHERICITY Infilling [%] COMMENTS 0.9 2.3 0.4 0.04 VESICLE 1.4 0.8 VESICLE subhedral to 0.9 0.5 subhedral 0.5 0.2 0.2 0.02 0.1 subhedral subhedral to anhedral laths[330] moderate[330] 100 inclined U1374A-39R-2-W 66_68

Proc. IODP | Volume 330 48 Site U1374 core descriptions Thin sections melt inclusions subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 186 86_88-BILLET186-SLIDE 330-U1374A-39R-5-W fragment lava lobe or PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseolivine phyric sparsely MICROPHENOCRYST ORIGINALolivine Unit:80 PERCENT REPLACED 2.3 REL. VOL.augiteplagioclaseopaque minerals 0.3GROUNDMASSglassplagioclase 1olivine 0 0.5SECONDARY 0.2MINERALOGY 60 0.2 97.7 0.1STRUCTURE min. 60 SIZE(mm)COMMENTS 0 max. 0 10 mode. 0 82.7 SECTION:SLIDE 186 OBSERVER:THIN DESCRIPTION SUMMARY MORPHOLOGY 6 Moderate trachytic texture towards ~020 degrees. 100 0 SPHERICITY Infilling [%] COMMENTS 100 1.2 VESICLE 5.4 1.2 VESICLE 0.7 anhedral 0.4 0.4 0.4 euhedral to 0.6 0.4 euhedral to 0.3 anhedral anhedral 0.1 0.1 anhedral 0.01 subhedral to anhedral laths[330] melt inclusions some skeletal crystals inclined U1374A-39R-5-W 86_88

Proc. IODP | Volume 330 49 Site U1374 core descriptions Thin sections anhedral laths[330] inclined subhedral to anhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. plagioclase 0.5 0 0.6 0.6 GROUNDMASSplagioclaseglassolivineSECONDARY MINERALOGY 97.5 STRUCTURECOMMENTS 20 DESCRIPTIONSUMMARY 72.5 5 Palagonized part in the right edge of the thin section. 0 sub vertical trachytic texture (towards (~0-010 degrees) NB in clast 100 100 0.4 0.1 0.2 0.01 THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 187 129_131-BILLET187-SLIDE 330-U1374A-40R-4-W volcanic breccia clast PRIMARY sparsely olivine-phyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained olivine sparsely phyric augiteMICROPHENOCRYST Unit:81 ORIGINALolivine PERCENT REPLACED 2.5 REL. VOL. 1 0.2 0.5 80 0 min. SIZE(mm) 30 max. mode. SECTION:SLIDE 187 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 2.4 1.4 1.2 VESICLE 0.8 0.4 subhedral anhedral subhedral plagioclase 0.3 0 1.4 1 anhedral U1374A-40R-4-W 129_131

Proc. IODP | Volume 330 50 Site U1374 core descriptions Thin sections brown clay alteration in cracks brown clay alteration in cracks subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 188 36_38-BILLET188-SLIDE 330-U1374A-41R-4-W lava lobe PRIMARY olivine-phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseolivine phyric sparsely MICROPHENOCRYST ORIGINALplagioclase Unit:82 PERCENT REPLACEDaugite REL. VOL. 2 olivineGROUNDMASS 0.2glassolivineplagioclase 1 0 0.1SECONDARY MINERALOGY 98 0.2 10 0.5STRUCTURE 0COMMENTS min. SIZE(mm) 0 max. 89 20 4 mode. DESCRIPTIONSUMMARY 5 SECTION:SLIDE 188 OBSERVER:THIN carbonate veins, 0.8 mm in size. MORPHOLOGY texture in bands. No structure in groundmass; weak trachytic 100 SPHERICITY 0 80 Infilling [%] COMMENTS 1.2 1 VESICLE 3.2 0.4 VESICLE 2 0.3 anhedral 0.9 0.6 euhedral to 0.6 0.4 anhedral 0.2 anhedral euhedral to 0.2 0.01 0.1 subhedral to anhedral laths[330] U1374A-41R-4-W 36_38

Proc. IODP | Volume 330 51 Site U1374 core descriptions Thin sections vesicle green along vesicle walls, zeolite interiors clay subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 189 103_105-BILLET189-SLIDE 330-U1374A-41R-6-W clast breccia volcanic PRIMARY olivine-phyric basalt moderately MINERALOGY Piece No:PHENOCRYSTS grained fine augiteplagioclase phyric moderately olivineMICROPHENOCRYST Unit:83 ORIGINALolivine PERCENT REPLACED 3.4 REL. VOL.VESICLESGROUNDMASSopaque mineralsplagioclase 0.3 0.1olivineglass 2SECONDARY 0 96.5 0MINERALOGY 1 0.1 0.5zeolite 60STRUCTURE min. 10 SIZE(mm)COMMENTS 30 max. mode. SECTION:SLIDE 189 OBSERVER:THIN 6 DESCRIPTION SUMMARY 80 0 MORPHOLOGY degrees (NB: this piece is from clast); carbonate vein (0.08 mm), irregular. strong trachytic texture towards ~030 SPHERICITY 90 Infilling [%] 100 COMMENTS 1.4 1 1.2 VESICLE 0.1 3.2 VESICLE 2.2 0.8 0.8 anhedral 0.2 0.3 0.6 0.2 anhedral subhedral 0.3 euhedral to 0.1 subhedral 0.2 0.05 laths[330] euhedral to anhedral high[330] 100 inclined; trachytic texture U1374A-41R-6-W 103_105

Proc. IODP | Volume 330 52 Site U1374 core descriptions Thin sections euhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 190 117_119-BILLET190-SLIDE 330-U1374A-42R-5-W fragment lava lobe or PRIMARY plagioclase-augite-phyric basalt moderately MINERALOGY Piece No:PHENOCRYSTS grained fine plagioclaseaugite phyric & plagioclase-augite glomeroporphyritic moderately MICROPHENOCRYST plagioclase Unit:84 ORIGINALaugite PERCENT REPLACEDGROUNDMASS REL. VOL. 7 augiteglass 1.5plagioclase 0.5SECONDARY 4 93 MINERALOGY 0STRUCTURE 1 0COMMENTS 0 4 min. SIZE(mm) 9 DESCRIPTION SUMMARY 80 0 max. mode. thin section) moderate trachytic texture (but non-oriented SECTION:SLIDE 190 OBSERVER:THIN 0 MORPHOLOGY 0 100 SPHERICITY Infilling [%] COMMENTS 1.2 1 VESICLE 1.3 0.9 VESICLE 0.8 tabular 0.8 0.5 0.3 euhedral tabular 0.4 0.1 0.2 subhedral subhedral to laths[330] centered and hour-glass zonning U1374A-42R-5-W 117_119

Proc. IODP | Volume 330 53 Site U1374 core descriptions Thin sections REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. STRUCTURE texture; carbonate vein (0.2 mm); irregular. zones of weak sub-vertical trachytic THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 191 119_121-BILLET191-SLIDE 330-U1374A-42R-6-W lava lobe or fragment PRIMARY basalt moderately olivine-plagioclase-phyric MINERALOGY Piece No:PHENOCRYSTS fine grained plagioclaseolivine moderately phyric MICROPHENOCRYST plagioclase Unit:86 ORIGINALolivine PERCENT REPLACEDGROUNDMASS REL. VOL. 9 plagioclaseglass 1 5 1 91 0 2 3 98 0 87 min. SIZE(mm) 100 0 max. mode. SECTION:SLIDE 191 OBSERVER:THIN 100 MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 1.8 1 VESICLE 3.5 0.9 1.4 VESICLE 0.5 0.9 anhedral 0.3 0.6 euhedral 0.1 anhedral subhedral laths[330] MINERALOGY COMMENTS DESCRIPTION SUMMARY olivineSECONDARY 1 100 0.1 0.05 anhedral iddingsite U1374A-42R-6-W 119_121

Proc. IODP | Volume 330 54 Site U1374 core descriptions Thin sections anhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. GROUNDMASSplagioclaseglass 97.5 3 89 0 100 0.3 0.1 laths[330] trachytic. SECONDARY MINERALOGY STRUCTURECOMMENTS DESCRIPTIONSUMMARY Skeletal olivine in the groundmasss. moderate trachytic texture towards ~010 degrees (NB in clast) THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 192 74_76-BILLET192-SLIDE 330-U1374A-43R-2-W volcanic breccia clast PRIMARY sparsely olivine-phyric[330] basalt MINERALOGY Piece No:PHENOCRYSTS fine grained olivine sparsely phyric MICROPHENOCRYST olivine ORIGINALplagioclase Unit:87 PERCENT REPLACED 2.5 REL. VOL.olivineopaque minerals 1 0.3 1 10 0.5 0 5 min. SIZE(mm) 5 max. mode. SECTION:SLIDE 192 OBSERVER:THIN MORPHOLOGY 90 SPHERICITY [%] Infilling COMMENTS VESICLE 2.8 0.8 1.3 VESICLE 0.8 0.5 0.5 0.2 euhedral 0.05 anhedral 0.2 subhedral 0.08 anhedral fresh Altered by iddingsite. skeletal. plagioclase 0.2 0 1.6 1.2 anhedral U1374A-43R-2-W 74_76

Proc. IODP | Volume 330 55 Site U1374 core descriptions Thin sections lite + clay. subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 195 83_85-BILLET195-SLIDE 330-U1374A-43R-7-W clast breccia volcanic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseMICROPHENOCRYST aphyric plagioclaseaugite ORIGINAL Unit:88 PERCENT REPLACEDolivine 5.5 REL. VOL.GROUNDMASSaugite 0.4glassolivine 3plagioclase 0 94.5 SECONDARY 2MINERALOGY 0 0.1STRUCTURE 1.5COMMENTS min. 0 SIZE(mm) 100 max. 83 7 mode. DESCRIPTIONSUMMARY 3 SECTION:SLIDE 195 OBSERVER:THIN 0Thin Section is carbonate and zeolite-cemented breccia. 2 veins filled with calcite, zeo The top part of the MORPHOLOGY degrees (NB in breccia clast) moderate trachytic texture towards ~130 100 SPHERICITY 0 100 Infilling [%] COMMENTS 1.3 1 VESICLE 0.9 0.5 VESICLE 0.9 0.5 tabular 0.4 tabular 0.1 euhedral to 0.08 0.2 0.2 euhedral 0.06 euhedral to 0.1 anhedral laths[330] iddingsite iddingsite U1374A-43R-7-W 83_85

Proc. IODP | Volume 330 56 Site U1374 core descriptions Thin sections shows that matrix material comprises 40% of total) shows that matrix material comprises Two small clasts w/ fresh glass Two vesicle SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 196 121_125-BILLET196-SLIDE 330-U1374A-44R-2-W clasts with matrix breccia volcanic PRIMARY basalt aphyric MINERALOGY Piece No:PHENOCRYSTS grained fine MICROPHENOCRYST olivine aphyric augiteplagioclase Unit:88 ORIGINALVESICLES PERCENT REPLACED REL. VOL. 0 1 3SECONDARY 2 5MINERALOGY calcite 100 0STRUCTURE 0COMMENTS min. SIZE(mm) max. mode. SECTION:SLIDE 196 OBSERVER:THIN DESCRIPTIONSUMMARY carbonate. One 2 mm patch of celadonite is present in matrix The matrix is dominantly MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.5 VESICLE 0.8 0.5 VESICLE 0.4 1 0.4 0.4 subhedral euhedral high[330] modal abundance Green clay + calcite + celadonite (Vesicle replaced by iddingsite on rims, green clay interiors GROUNDMASSolivineplagioclaseaugiteglass 60 6 1 2 45 0 100 0 75 0.2 0.5 laths[330] iddingsite U1374A-44R-2-W 121_125

Proc. IODP | Volume 330 57 Site U1374 core descriptions Thin sections laths[330] subhedral iddingsite REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. augiteplagioclaseSECONDARY MINERALOGY 2 1STRUCTURECOMMENTS 0 0 DESCRIPTIONSUMMARY voids are filled with carbonate, celadonite and goethite No structure in groundmass 0.9 0.7 0.5 0.4 tabular subhedral (sometimes) centered-zoning centered-zoning and polysynthetic twinning THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 197 18_20-BILLET197-SLIDE 330-U1374A-44R-3-W volcanic breccia clast PRIMARY aphyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained MICROPHENOCRYST aphyric & augite-plagioclase glomeroporphyritic olivine ORIGINAL Unit:88 PERCENT REPLACED 3.7 REL. VOL. 0.2 100 min. SIZE(mm) max. mode. SECTION:SLIDE 197 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 0.5 0.3 VESICLE GROUNDMASSolivineglassplagioclase 96.3 2.5 4.3 89 100 100 0 0.2 0.1 0.2 0.1 anhedral iddingsite, skeletal plagioclase 0.5 0 1.5 1.2 tabular twinning centered-zoning and polysynthetic augite 0.5 0 0.15 0.02 anhedral U1374A-44R-3-W 18_20

Proc. IODP | Volume 330 58 Site U1374 core descriptions Thin sections anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 198 22_24-BILLET198-SLIDE 330-U1374A-45R-7-W clast breccia volcanic PRIMARY plagioclase-phyric[EXP330] basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseMICROPHENOCRYST phyric & plagioclase-augite glomeroporphyritic moderately augiteplagioclase ORIGINALolivine Unit:88 PERCENT REPLACEDGROUNDMASS 6.7 REL. VOL.glassaugite 2olivineplagioclase 93.3 3 1.5SECONDARY 0MINERALOGY 0.2STRUCTURE 0 0COMMENTS 85.8 0.5 100 min. SIZE(mm) 5 DESCRIPTION max.SUMMARY 2 100 mode. with carbonate + green clay. Small veins are filled SECTION:SLIDE 198 OBSERVER:THIN are sigmoidal (0.16 mm in size); no structure in groundmass. Veins 0 MORPHOLOGY 0 100 SPHERICITY Infilling [%] COMMENTS 1.6 1.2 VESICLE 0.8 0.8 VESICLE 0.8 0.6 0.4 tabular 0.5 0.08 subhedral tabular 0.03 subhedral 0.2 0.2 0.1 0.1 subhedral to anhedral laths[330] iddingsite iddingsite U1374A-45R-7-W 22_24

Proc. IODP | Volume 330 59 Site U1374 core descriptions Thin sections replaced by iddingsite, skeletal texture replaced by iddingsite, skeletal Vesicles filled with zeolite & green clay. filled Vesicles 99.1 ite & goethite. Moderate trachytic texture towards 260 degrees; irregular ite & goethite. Moderate trachytic VESICLE VESICLE vesicle with green clay also filled subhedral[330] ) mm ( SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS 88.5 100 moderate trachytic texture towards ~250 degrees (note: in volcanic breccia; clay inside smectite rim); small amounts of celadon ~250 degrees (note: in volcanic breccia; clay inside moderate trachytic texture towards carbonate networks (0.4 mm in size). carbonate networks (0.4 mm THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 199 140_142-BILLET199-SLIDE 330-U1374A-46R-6-W volcanic breccia PRIMARY aphyric basalt Piece No: fine grained aphyric Unit:89 PERCENT REL. VOL. SIZE SECTION:SLIDE 199 OBSERVER:THIN GROUNDMASSaugiteolivineplagioclaseglass 100 MINERALOGY zeolite 0.5STRUCTURE COMMENTS 2 9 0 DESCRIPTION SUMMARY 100 0 0.2 0.4 0.05 0.4 0.1 0.2 anhedral euhedral to laths[330] inclined SECONDARY MINERALOGYPHENOCRYSTSMICROPHENOCRYST VESICLES ORIGINAL REPLACED 0 min. max. mode. MORPHOLOGY SPHERICITY [%] Infilling COMMENTS U1374A-46R-6-W 140_142

Proc. IODP | Volume 330 60 Site U1374 core descriptions Thin sections palagonite n clast. vesicle rim zeolite SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 200 133_135-BILLET200-SLIDE 330-U1374A-47R-1-W beccia volcanic PRIMARY basalt aphyric MINERALOGY Piece No:PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric GROUNDMASSplagioclase Unit:91 ORIGINALaugite PERCENT REPLACEDolivine REL. VOL. 0 glassSECONDARY 99.5 MINERALOGY 0.5green clay 10STRUCTURECOMMENTS 0.5 3 0 DESCRIPTIONSUMMARY 86 volcanic breccia. Carbonate, celadonite, small amounts of goethite. Small zeolite veins i carbonate cemented min. SIZE(mm) No structure in groundmass 0 100 max. mode. SECTION:SLIDE 200 OBSERVER:THIN 100 MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.08 0.4 0.2 VESICLE 0.4 VESICLE 0.1 0.3 0.4 0.05 0.1 laths[330] anhedral anhedral low[330] 100 with green clay. rim of zeolite & filled iddingsite, skeletal U1374A-47R-1-W 133_135

Proc. IODP | Volume 330 61 Site U1374 core descriptions Thin sections replaced by iddingsite and smectite, carbonite replaced by iddingsite and smectite, carbonite replaced by iddingsite and smectite, 0 green and in groundmass. clay in only a few tiny vesicles vesicle small and only a few vesicles very subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS GROUNDMASSglassolivineplagioclaseSECONDARY MINERALOGY 91 green clay STRUCTURECOMMENTS 86 3 2 DESCRIPTION SUMMARY veins (0.08 mm in size). No structure in groundmass; irregular 100 0 100 0.1 0.1 0.01 0.05 small laths anhedral iddingsite THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 202 80_82-BILLET202-SLIDE 330-U1374A-47R-3-W with sandy matrix breccia volcanic PRIMARY plagioclase-augite-phyric basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseaugite glomeroporphyritic phyric & aphanitic[330] & plagioclase-augite moderately olivine ORIGINALMICROPHENOCRYST Unit:92 PERCENT REPLACEDaugite REL. VOL. 9 olivineplagioclase 2VESICLES 1 0.5 0 2 100 0 0.5 3 min. SIZE(mm) max. 100 0 mode. SECTION:SLIDE 202 OBSERVER:THIN 0 MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 3.2 1.2 VESICLE 2.4 1.6 1.5 VESICLE 1.3 tabular 0.8 0.8 euhedral to 0.5 euhedral 0.8 0.5 0.4 euhedral to euhedral tabular Sometimes equigranular U1374A-47R-3-W 80_82

Proc. IODP | Volume 330 62 Site U1374 core descriptions Thin sections smectite, iddingsite smectite, iddingsite 100 filled with carbonate & zeolite. vesicles vesicle also filled with zeolite subhedral[330] subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS GROUNDMASSplagioclaseolivineglassSECONDARY MINERALOGY 88 carbonate STRUCTURE 1COMMENTS 2 DESCRIPTIONSUMMARY 85 0 clay & carbonate; widening from 0.08 to 2 m; no structure in groundmass. veins filled with zeolite, No structure in groundmass 100 100 0.1 0.1 0.2 0.02 laths[330] anhedral iddingsite THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 203 102_104-BILLET203-SLIDE 330-U1374A-47R-7-W breccia volcanic PRIMARY plagioclase-augite-phyric basalt moderately MINERALOGY Piece No:PHENOCRYSTS grained fine augite phyric & plagioclase-augite glomeroporphyritic moderately olivine Unit:93 ORIGINALplagioclase PERCENT REPLACEDMICROPHENOCRYST 12 REL. VOL.augiteolivineplagioclase 2VESICLES 0.8 3 0 100 1 0 min. SIZE(mm) 0.2 4 max. mode. SECTION:SLIDE 203 OBSERVER:THIN 0 100 MORPHOLOGY 0 SPHERICITY Infilling [%] COMMENTS 2.4 VESICLE 1.3 1.5 1.2 VESICLE 2.8 1.3 euhedral to euhedral to 0.8 0.9 0.5 tabular 0.4 0.8 0.5 euhedral to euhedral to tabular numerous fresh melt inclusions U1374A-47R-7-W 102_104

Proc. IODP | Volume 330 63 Site U1374 core descriptions Thin sections oscillatory zonation sometimes oscillatory zonation subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 205 205-SLIDE 20_23-BILLET 330-U1374A-48R-8-W lava fragment PRIMARY plagioclase-phyric[EXP330] basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine augiteplagioclase phyric moderately olivine ORIGINALMICROPHENOCRYST Unit:94 PERCENT REPLACEDolivine 9.5 REL. VOL.plagioclaseaugiteVESICLES 3 0.5GROUNDMASSplagioclaseglass 0.5olivine 0 0 4 0.5SECONDARY MINERALOGY 100 90 1 0.5 min. SIZE(mm)STRUCTURE 100 0 max.COMMENTS 2 mode. SECTION:SLIDE 205 OBSERVER:THIN 0 MORPHOLOGY DESCRIPTIONSUMMARY 87 1 carbonate veins (1mm in size); goethite SPHERICITYsigmoidal. No structure in groundmass; vein is 0 Infilling [%] COMMENTS 100 100 4.5 2 VESICLE 1.2 1.2 1.7 VESICLE 1.2 0.9 0.9 tabular 0.6 euhedral 0.4 subangular 0.8 3.2 subangular 0.4 0.1 tabular 0.01 euhedral to 0.1 0.01 laths[330] anhedral glomerocrysts, and/or Texture", Sometimes "Sieve zoned iddingsite + green clay + carbonate elongate[330] iddingsite + green clay + carbonate 100 Texture" Sometimes "Sieve iddingsite U1374A-48R-8-W 20_23

Proc. IODP | Volume 330 64 Site U1374 core descriptions Thin sections crystals sometimes have zonation smectite and brown clay smectite and brown clay subhedral[330] subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 206 92_94-BILLET206-SLIDE 330-U1374A-49R-1-W by zeolite clasts cemented breccia volcanic PRIMARY plagioclase-phyric[EXP330] basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine augite moderately phyric plagioclaseolivine ORIGINAL Unit:95 PERCENT REPLACEDMICROPHENOCRYST REL. VOL. 9 olivineplagioclaseaugite 0.8 1GROUNDMASSplagioclase 0.2glass 0olivine 0SECONDARY 3 100 3MINERALOGY min. SIZE(mm) 91 max.STRUCTURE 1 mode. 100COMMENTS 1 SECTION:SLIDE 206 OBSERVER:THIN 0 MORPHOLOGY DESCRIPTIONSUMMARY 89.5 0 SPHERICITY 0.5 with palagonatized rims & smectites. Altered glass clasts No structure in groundmass Infilling [%] 0 COMMENTS 100 100 1.2 VESICLE 1.4 1.1 1.1 1.2 VESICLE 1.1 euhedral to tabular clots[330] 0.8 euhedral to 0.7 0.4 0.3 0.8 euhedral to tabular clots[330] 0.1 0.4 0.01 0.1 euhedral to 0.01 small laths clots anhedral iddingsite U1374A-49R-1-W 92_94

Proc. IODP | Volume 330 65 Site U1374 core descriptions Thin sections iddingsite green clay in groundmass matrix. euhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 208 43_45-BILLET208-SLIDE 330-U1374A-51R-6-W lobe? pillow or lava PRIMARY plagioclase-phyric[EXP330] basalt moderately MINERALOGY No: Piece PHENOCRYSTS grained fine augiteplagioclase moderately phyric olivine ORIGINALMICROPHENOCRYST Unit:101 PERCENT REPLACEDplagioclase REL. VOL. 8 olivineaugite 2 0.2GROUNDMASSglass 0.4plagioclaseolivine 4 0SECONDARY 100 0.1MINERALOGY 92 min. SIZE(mm) 1.3STRUCTURE max.COMMENTS 100 mode. SECTION:SLIDE 208 OBSERVER:THIN 2 89 MORPHOLOGY DESCRIPTION SUMMARY 1 SPHERICITYirregular (0.2 m in size & width), filled with carbonate & clay; green clay in the No structure in groundmass; vein is Infilling [%] 0 0 COMMENTS 100 4.5 1.3 VESICLE 2.8 1.1 VESICLE 2 tabular clots[330] 0.9 0.8 0.3 euhedral to euhedral 0.8 tabular clots[330] 0.9 euhedral to 0.4 0.1 0.02 0.2 subhedral to 0.01 small laths some crystals have melt inclusions, oscillatory zonation anhedral some small melt inclusions small melt inclusions oscillatory zonation, some iddingsite U1374A-51R-6-W 43_45

Proc. IODP | Volume 330 66 Site U1374 core descriptions Thin sections altered to smectite and iddingsite altered to smectite and iddingsite partly fresh, altered to palagonite altered to iddingsite vesicle with clay also filled anhedral[330] subhedral[330] subhedral[330] subhedral[330] subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 207 78_82-BILLET207-SLIDE 330-U1374A-51R-6-W by zeolite clasts cemented breccia, volcanic PRIMARY phyric basalt sparsely MINERALOGY No: Piece PHENOCRYSTS grained fine olivine & aphanitic[330] & sometimes glomeroporphyritic phyric sparsely augite ORIGINALMICROPHENOCRYST Unit:102 PERCENT REPLACEDaugite REL. VOL. 4 plagioclaseolivine 0.6VESICLESGROUNDMASS 0.4glassolivine 100 0.5plagioclase 0.5 0SECONDARY min. SIZE(mm) 96 MINERALOGY 2 0.1 0 10 max.carbonate mode. SECTION:SLIDE 207 OBSERVER:THIN STRUCTURE MORPHOLOGY 100COMMENTS 91 3 2 SPHERICITY Infilling [%] DESCRIPTIONSUMMARY COMMENTS 90 and some patches of carbonate, some geothite voids are filled with zeolite Palagonatized clasts also. 100 0 1.7 1.2 VESICLE 2 VESICLE euhedral to 1.2 0.8 0.9 0.5 0.3 0.5 euhedral to 0.8 1.2 0.4 1 euhedral to subhedral euhedral to 0.1 0.01 0.2 0.02 subhedral to small laths moderate[330] 100 centered zoning in clast filled with carbonate and clay U1374A-51R-6-W 78_82

Proc. IODP | Volume 330 67 Site U1374 core descriptions Thin sections low to 100 goethite filled with celadonite & small amounts of elongated[EXP330] vesicle small amounts of goethite anhedral iddingsite REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. GROUNDMASSglassolivineplagioclaseSECONDARY MINERALOGY 60 celadonite STRUCTURECOMMENTS 56.3 3 0.5 DESCRIPTION SUMMARY 100 No structure in groundmass 100 0 0.1 0.3 0.05 0.2 laths[330] THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 209 209-SLIDE 33_35-BILLET 330-U1374A-52R-2-W vesicular basalt PRIMARY aphyric basalt MINERALOGY No: Piece PHENOCRYSTS fine grained MICROPHENOCRYST VESICLES aphyric ORIGINAL Unit:103 PERCENT REPLACED REL. VOL. 0 40 min. SIZE(mm) max. mode. SECTION:SLIDE 209 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.02 0.8 0.2 VESICLE VESICLE U1374A-52R-2-W 33_35

Proc. IODP | Volume 330 68 Site U1374 core descriptions Thin sections some filled with green clay and celadonite some filled with green clay and vesicle celadonite anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 210 210-SLIDE 38_40-BILLET 330-U1374A-54R-4-W breccia volcaniclastic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine augiteMICROPHENOCRYST + olivine bunched clots in groundmass aphyric & plagioclase + augite augiteVESICLES ORIGINALGROUNDMASS Unit:105 PERCENT REPLACEDplagioclase 0.5 REL. VOL.augiteolivineglass 0.3 99.5 SECONDARY 0.2MINERALOGY green clay 5 0STRUCTURE 0COMMENTS 2 min. SIZE(mm) 0 3 DESCRIPTION max.SUMMARY 89.5 mode. SECTION:SLIDE 210 OBSERVER:THIN goethite (?) & carbonate veins filled with zeolite, 0 are straight to irregular. trachytic texture (toward 000 degrees); veins No structure in groundmass. Vertical MORPHOLOGY 100 100 SPHERICITY Infilling [%] COMMENTS 1.7 VESICLE 0.8 VESICLE 0.5 0.8 0.4 subhedral 0.4 subhedral 0.5 0.1 laths[330] 0.1 euhedral to anhedral subhedral to poorly aligned iddingsite U1374A-54R-4-W 38_40

Proc. IODP | Volume 330 69 Site U1374 core descriptions Thin sections low[330] 100 filled with carbonate ass vesicle REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. GROUNDMASSplagioclasepyriteaugiteglass 97 carbonate 50STRUCTURECOMMENTS 2 20 1 DESCRIPTION SUMMARY 43 and perccentage of vesicles; no structure in groundm sizes bands strike 056-236 degrees, and contain different Vesicle 0 100 0.7 0.5 0.02 0.04 laths[330] 0.01 0.01 subhedral anhedral THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 211 211-SLIDE 4_6-BILLET 330-U1374A-55R-2-W intrusive sheet PRIMARY aphyric basalt MINERALOGYPHENOCRYSTS No: Piece fine grained MICROPHENOCRYST VESICLES aphyric & intersertal ORIGINAL PERCENT REPLACED Unit:106 REL. VOL. 0 3 min. SIZE(mm) max. mode. SECTION:SLIDE 211 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 0.2 5 VESICLE 0.3 VESICLE SECONDARY MINERALOGY U1374A-55R-2-W 4_6

Proc. IODP | Volume 330 70 Site U1374 core descriptions Thin sections vesicle (?) zeolite anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 212 212-SLIDE 130_133-BILLET 330-U1374A-55R-3-W breccia volcaniclastic PRIMARY basalt aphyric No: Piece MINERALOGYPHENOCRYSTS grained fine augiteMICROPHENOCRYST aphyric & sometimes glomeroporphyritic augiteVESICLES Unit:107 ORIGINALGROUNDMASS PERCENT REPLACEDaugite 0.5 REL. VOL.olivineglassplagioclase 0.1 94.5 SECONDARY 5 0.4MINERALOGY clay 0 0.5STRUCTURE 0COMMENTS 2 min. SIZE(mm) 6 86 0 DESCRIPTION max.SUMMARY SECTION:SLIDE 212 OBSERVER:THIN mode. 100 MORPHOLOGY 15 100 SPHERICITY Infilling [%] COMMENTS 0.3 1.1 VESICLE 7 1 0.4 VESICLE 0.4 6 0.3 anhedral 0.1 0.5 subhedral 0.8 0.2 0.3 subhedral to anhedral laths[330] low[330] 10 green clay U1374A-55R-3-W 130_133

Proc. IODP | Volume 330 71 Site U1374 core descriptions Thin sections vesicle anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 213 13_15-BILLET213-SLIDE 330-U1374A-56R-4-W breccia volcaniclastic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine augiteMICROPHENOCRYST aphyric & sometimes glomeroporphyritic augiteVESICLES ORIGINALGROUNDMASS Unit:107 PERCENT REPLACEDaugite 0.5 REL. VOL.plagioclaseglassolivine 0.1 94.5 SECONDARY 5 0.4MINERALOGY calcite 0 0.5STRUCTURE 6 0COMMENTS min. SIZE(mm) 86 0 DESCRIPTION max.SUMMARY 2 15 mode. SECTION:SLIDE 213 OBSERVER:THIN (altered) phenocrysts celadonite around some weak trachytic texture towards 090 degrees MORPHOLOGY 100 100 SPHERICITY Infilling [%] COMMENTS 0.3 1.1 VESICLE 7 0 0.4 VESICLE 0.4 6 0.3 0.8 anhedral 0.1 subhedral 0.3 0.5 subhedral to 0.2 laths[330] anhedral low[330] 10 carbonate green clay U1374A-56R-4-W 13_15

Proc. IODP | Volume 330 72 Site U1374 core descriptions Thin sections elongated[EXP330] vesicle with pyrite also filled tabular subhedral anhedral[330] 0.1 SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS STRUCTURE of vesicles. Non-oriented thin section. sizes and percentage abundance bands contain different Vesicle augite 2 0 0.2 0.1 subhedral to THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 214 28_32-BILLET214-SLIDE 330-U1374A-58R-4-W intrusive sheet PRIMARY aphyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained aphyric ORIGINAL Unit:116 PERCENT REPLACED 0.5 REL. VOL. min. SIZE(mm) max. mode. SECTION:SLIDE 214 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE VESICLE augiteVESICLESGROUNDMASSplagioclaseglasspyrite 15 0.4 84.5 30 0 50.5 0 2 100 0.04 1.6 0.6 0.2 0.5 0.4 0.2 anhedral laths[330] low and 100 zeolite; some pyrite SECONDARY MINERALOGY zeolite COMMENTS DESCRIPTIONSUMMARY Irregular vein filled with pyrite + zeolite (0.4 mm). MICROPHENOCRYST plagioclase 0.1 0 0.4 0.4 U1374A-58R-4-W 28_32

Proc. IODP | Volume 330 73 Site U1374 core descriptions Thin sections some occur as glomerocryst with plagioclase some occur as glomerocryst imately 270-090 degrees. Vesicle bands are parallel to the contact. imately 270-090 degrees. Vesicle vesicle vesicle euhedral[330] anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 215 70_72-BILLET215-SLIDE 330-U1374A-58R-4-W (intrusive sheet) lava massive PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine plagioclaseMICROPHENOCRYST aphyric & glomerocrystic clinopyroxene ORIGINALplagioclase Unit:116 PERCENT REPLACEDVESICLES 0.5 REL. VOL.GROUNDMASSplagioclaseglass 0.2pyrite 0.1clinopyroxene 30 0.2 69 SECONDARY 0 30MINERALOGY zeolite 10carbonate 0 min. SIZE(mm)STRUCTURE 30 10 max.COMMENTS 1 mode. SECTION:SLIDE 215 OBSERVER:THIN MORPHOLOGY DESCRIPTIONSUMMARY 50 No structure in groundmass. SPHERICITY rim along contact with country rock. the contact is curved, but strikes approx Intrusive sheet has glass-rich quenched Infilling [%] COMMENTS 2 0.5 1.2 0.02 VESICLE 0.3 0.9 1.2 VESICLE subhedral 0.4 0.15 subhedral to 0.2 subhedral 0.03 0.15 0.03 0.03 subhedral 0.01 subhedral subhedral to low[330] glomerocryst 50 filled with zeolite + carbonate some occur as glomerocryst U1374A-58R-4-W 70_72

Proc. IODP | Volume 330 74 Site U1374 core descriptions Thin sections anhedral[330] anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 3_5-BILLET216-SLIDE 216 330-U1374A-61R-1-W breccia (clast) volcaniclastic PRIMARY plagioclase-phyric[EXP330] basalt moderately MINERALOGYPHENOCRYSTS Piece No: grained fine plagioclaseMICROPHENOCRYST moderately phyric plagioclaseaugite ORIGINAL PERCENT REPLACEDGROUNDMASS Unit:129 5.2 REL. VOL.glassaugite 2plagioclase 3SECONDARY 94.8 MINERALOGY 0 0.2STRUCTURE 0COMMENTS 92.5 0 0.3 min. SIZE(mm) 2 DESCRIPTIONSUMMARY max. 100 with smectite rims (celadonite). Cemented by zeolite Altered glassy clasts mode. no structure in groundmass. 0 SECTION:SLIDE 216 OBSERVER:THIN MORPHOLOGY 10 SPHERICITY Infilling [%] COMMENTS 2.4 1.2 VESICLE 0.9 0.5 VESICLE 0.5 tabular 0.4 tabular 0.1 subhedral to 0.2 0.04 0.09 subhedral to laths[330] U1374A-61R-1-W 3_5

Proc. IODP | Volume 330 75 Site U1374 core descriptions Thin sections carbonate. moderate[EXP330] vesicleTS only in the lower part of this anhedral subhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. plagioclaseVESICLESGROUNDMASSaugiteplagioclaseglass 2SECONDARY 50MINERALOGY 87 zeolite 10 2 0.5 84.5 0 0 100 0.06 0.9 3 0.5 0.4 tabular 0.2 0.1 0.05 0.1 laths[330] low to 100 lower part of the thin section filled by/with zeolite & Vesicular fractured! laths are small THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 217 9_12-BILLET217-SLIDE 330-U1374A-62R-3-W volcaniclastic breccia PRIMARY basalt moderately plagioclase-phyric[EXP330] MINERALOGYPHENOCRYSTS No: Piece fine grained plagioclaseMICROPHENOCRYST moderately phyric augite ORIGINAL PERCENT Unit:131 REPLACED 13 REL. VOL. 9 1 10 0 min. SIZE(mm) max. mode. SECTION:SLIDE 217 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS 3.2 2.5 VESICLE 0.6 VESICLE tabular 0.3 fractured! STRUCTURECOMMENTS DESCRIPTIONSUMMARY Green clay in small/tiny vesicles. No structure in groundmass. U1374A-62R-3-W 9_12

Proc. IODP | Volume 330 76 Site U1374 core descriptions Thin sections elongated[EXP330] vesicle with carbonate and a smectite rim also filled laths[330] subhedral subhedral to anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS plagioclaseVESICLES 1 10 0 0.1 0.9 3 0.7 0.4 tabular low and 40 filled by zeolite and carbonate (smectite rim) THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 218 38_40-BILLET218-SLIDE 330-U1374A-64R-2-W intrusive sheet PRIMARY aphyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained MICROPHENOCRYST aphyric augite ORIGINAL Unit:136 PERCENT REPLACED 1.6 REL. VOL. 0.5 0 min. SIZE(mm) max. mode. SECTION:SLIDE 218 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 0.8 VESICLE 0.4 SECONDARY MINERALOGY zeolite STRUCTURECOMMENTS DESCRIPTIONSUMMARY Abundant augite in groundmass. no structure in groundmass. plagioclase 30 80 0.3 0.2 GROUNDMASSglassaugite 88.4 54.4 5 100 0 0.3 0.1 plagioclase 0.1 0 1.3 tabular U1374A-64R-2-W 38_40

Proc. IODP | Volume 330 77 Site U1374 core descriptions Thin sections skeletal, fresh subhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 219 129_132-BILLET219-SLIDE 330-U1374A-64R-6-W breccia (clast) volcaniclastic PRIMARY basalt aphyric MINERALOGY Piece No:PHENOCRYSTS grained fine MICROPHENOCRYST GROUNDMASS aphyric plagioclaseglass Unit:137 ORIGINALolivine PERCENT REPLACED REL. VOL. 0 SECONDARY 100 MINERALOGY STRUCTURE 25COMMENTS 74.5 0.5 DESCRIPTION SUMMARY 0 strong trachytic texture (but non-oriented piece) 100 min. SIZE(mm) 0 max. SECTION:SLIDE 219 OBSERVER:THIN mode. MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 1 VESICLE 0.3 VESICLE 0.2 0.1 laths[330] euhedral to aligned U1374A-64R-6-W 129_132

Proc. IODP | Volume 330 78 Site U1374 core descriptions Thin sections altered to clay vesicle also filled with zeolite, palagonite, clay and some calcite anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 220 29_31-BILLET220-SLIDE 330-U1374A-66R-4-W breccia volcanic PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST opaque minerals aphyric plagioclase ORIGINALVESICLES Unit:136 PERCENT REPLACEDGROUNDMASS REL. VOL. 3 glassplagioclase 0.5SECONDARY MINERALOGY zeolite 2.5 47 50STRUCTURE COMMENTS 0 3 44 DESCRIPTIONSUMMARY min. SIZE(mm) zeolite voids are filled with max. mode. 100 SECTION:SLIDE 220 OBSERVER:THIN MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.8 0.2 0.03 VESICLE 0.8 1.2 subhedral to 0.3 VESICLE 0.06 laths[330] 0.1 0.05 laths[330] high to low 100+ palagonite + clay and some calcite filled with zeolite small laths U1374A-66R-4-W 29_31

Proc. IODP | Volume 330 79 Site U1374 core descriptions Thin sections palagonite vesicle minor zeolite laths[330] subhedral subhedral REPLACING/FILLING COMMENTS SIZE(mm) min. max. mode. clinopyroxene 0.5 0.06 0.03 SECONDARY MINERALOGY plagioclaseclinopyroxeneVESICLESGROUNDMASSolivine 4 2 23 70 0.5 0.1 1.8 0.5 5.5 0.25 0.4 1 subhedral 0.06 subhedral 0.04 subhedral moderate[330] 50 + minor zeolite rim of green clay (sapolite) sector zoning, glomerocryst glomerocryst THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 221 81_83-BILLET221-SLIDE 330-U1374A-69R-3-W gravel vitric-lithic volcanic sand and PRIMARY aphyric basalt MINERALOGY Piece No:PHENOCRYSTS fine grained MICROPHENOCRYST olivine glomerophyric ORIGINAL Unit:142 PERCENT REPLACED REL. VOL. 7 1 min. SIZE(mm) max. mode. SECTION:SLIDE 221 OBSERVER:THIN MORPHOLOGY SPHERICITY [%] Infilling COMMENTS VESICLE 0.15 VESICLE 0.1 glass 20 100 opaque mineralsgreen clay STRUCTURE 0.5COMMENTS DESCRIPTIONSUMMARY voids are filled with zeolite No structure in groundmass 0.03 0.01 subhedral plagioclase 1 0.1 0.05 U1374A-69R-3-W 81_83

Proc. IODP | Volume 330 80 Site U1374 core descriptions Thin sections Altered in the volcanic Unit 148, but some fresh glass in the Altered in the volcanic Unit 148, vitric-lithic volcanic gravel (Unit 147) vitric-lithic volcanic gravel (Unit nched flow top, or top of chilled intrusion? anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS opaque mineralsplagioclaseSECONDARY MINERALOGY 1STRUCTURECOMMENTS 45 DESCRIPTIONSUMMARY 0 veins are straight (0.6 mm); 2 veins filled with zeolite (clay at the rim) voids are filled with zeolite; material becomes blacker towards the contact with sediments - que texture towards ~250 degrees. Interstitial Trachytic 0 0.17 0.03 0.4 subhedral to 0.1 laths[330] THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 222 53_55-BILLET222-SLIDE 330-U1374A-72R-1-W sheet) and Unit 148 (intrusive Unit 147 (vitric-lithic volcanic gravel) boundary of PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST clinopyroxene aphyric plagioclaseVESICLES ORIGINALGROUNDMASS Unit:147 & 148 PERCENT REPLACEDolivine REL. VOL. 2 glass 1 1 98 0 10 43 min. SIZE(mm) SECTION:SLIDE 222 OBSERVER:THIN 100 max. mode. 90 MORPHOLOGY SPHERICITY Infilling [%] COMMENTS 0.4 VESICLE 0.2 0.5 0.3 VESICLE 0.15 subhedral 0.08 subhedral subhedral only in Unit 147 only in Unit 147 skeletal crystals U1374A-72R-1-W 53_55

Proc. IODP | Volume 330 81 Site U1374 core descriptions Thin sections subophitic altered to green clay anhedral[330] anhedral[330] SIZE(mm) min. max. mode. REPLACING/FILLING COMMENTS THIN SECTION:ROCK NAME:WHERE SAMPLED:GRAINSIZE:TEXTURE: 223 32_35-BILLET223-SLIDE 330-U1374A-72R-2-W basalt massive PRIMARY basalt aphyric MINERALOGY No: Piece PHENOCRYSTS grained fine MICROPHENOCRYST VESICLES aphyric GROUNDMASSclinopyroxene ORIGINAL Unit:148 PERCENT REPLACEDglass REL. VOL. 0 opaque mineralsplagioclase 100 olivine 0 25SECONDARY MINERALOGY 10STRUCTURE 0COMMENTS 13 45 0 min. SIZE(mm) DESCRIPTION SUMMARY 100 max. 7 mode. ~020 to 040 degrees. zones of weak-moderate trachytic texture towards SECTION:SLIDE 223 OBSERVER:THIN 0 MORPHOLOGY 0 SPHERICITY Infilling [%] COMMENTS 0.1 VESICLE 0.05 0.03 VESICLE 0.02 subhedral to subhedral to 0.4 0.1 0.1 0.08 laths[330] subhedral U1374A-72R-2-W 32_35

Proc. IODP | Volume 330 82 Site U1374 core descriptions Thin sections

Proc. IODP | Volume 330 83