Leg : 64 Top/Bottom Interval(mm): 10/ 40 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: METAMORPHIC Core: 18 Sample Midpoint(m) : 158.03 Sect/Pc #: 1/PCE 1 ROCK = METABASALT ENCODED FROM THE ICD; Texture: PHYRIC FINE-GRAINED GROUNDMASS,NO FOLIATION; Phenocrysts- CLINOPYROXENE ALTERED; OLIVINE ALTERED* Alteration - CALCITE Location: VEINS Leg : 64 Top/Bottom Interval(mm): 70/ 100 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: METAMORPHIC Core: 18 Sample Midpoint(m) : 158.09 Sect/Pc #: 1/PCE 2 ROCK = METAQUARTZITE ENCODED FROM THE ICD; Groundmass - QUARTZ ( 80%) Size(mm): .00025 RAGGED EDGES,RECRYSTALLIZED UNDULATING EXTINCTION, SET IN LACY MICA FRAMEWORK; MICA EPIDOTE Alteration - MICA EPIDOTE Leg : 64 Top/Bottom Interval(mm): 180/ 200 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: SEDIMENTARY Core: 18 Sample Midpoint(m) : 158.19 Sect/Pc #: 1/PCE 4 ROCK = QUARTZ SANDSTONE ENCODED FROM THE ICD,LOW-GRADE,CEMENTED BY ALTERED CLAY,GRAINS ROUNDED SUBHEDRAL OR ANGULAR-MANY HIGHLY WEATHERED TO SERICITE; Groundmass - SILICA PYROXENE SCATTERED,FELDSPAR-RICH* Alteration - SERICITE Leg : 64 Top/Bottom Interval(mm): 240/ 260 Describer: Saunders, A. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: SEDIMENTARY Core: 18 Sample Midpoint(m) : 158.25 Sect/Pc #: 1/PCE 5 ROCK = RECRYSTALLIZED TRACHYTE; Texture: PORPHYRITIC,FINE-GRAINED,PILOTAXITIC; Where sampled: OTHER BLOCK IN CONGLOMERATE* Phenocrysts- SPHENE ( 3%) Size(mm): 0.1-0.5 Morphology: CUBIC-IRREGULAR REDDISH,REPLACING TITAN.MT; KFELDSPAR ( 10%) Size(mm): 0.5-2 Morphology: SUBHEDRAL-EUHEDRAL ORTHOCLASE OR SANIDINE,RATHER BADLY ALTERED* Groundmass - OLIVINE ( 0%) PLAGIOCLASE ( 40%) Size(mm): <0.4 Morphology: LATHS QUARTZ ( 30%) Size(mm): <0.2 INTERSTITIAL,INTERGROWN WITH FELDSPAR CHLORITE ( 15%) Size(mm): 0.05-0.5 Morphology: ELONGATE STRANDS PLEOCHROIC GREEN,ANOMALOUS INTERFERENCE COLORS, IDENTITY UNCERTAIN FOR CHLORITE* Alteration - PREHNITE ( 5%) Replacing: AMPHIBOLE RANDOM PSEUDOMORPHS,REPLACING AMPHIBOLE IS QUESTIONABLE* Leg : 64 Top/Bottom Interval(mm): 430/ 500 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: METAMORPHIC Core: 18 Sample Midpoint(m) : 158.47 Sect/Pc #: 1/PCE 8 ROCK = METAMORPHOSED CONGLOMERATE ENCODED FROM THE ICD,MOSTLY ROCK FRAGMENTS, METAMORPHIC,LOW-GRADE,CLASTS INCLUDE LAMINATED QUARTZ SILISTONE+COARSE WEATHERED GRANITE+ QUARTZ-MICA SCHIST,MOST FRACTURED+BROKEN,TRACE OF BLACK BITUMEN IMPREGNATION,CLAY MINERAL AND QUARTZ CEMENT; Alteration - CLAY MINERALS Leg : 64 Top/Bottom Interval(mm): 650/ 740 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 158.00 Rock Type: METAMORPHIC Core: 18 Sample Midpoint(m) : 158.70 Sect/Pc #: 1/PCE 11 ROCK = METAMORPHOSED CONGLOMERATE ENCODED FROM THE ICD,MOSTLY ROCK FRAGMENTS, METAMORPHIC,LOW-GRADE,CLASTS INCLUDE LAMINATED QUARTZ SILISTONE+COARSE WEATHERED GRANITE+ QUARTZ-MICA SCHIST,MOST FRACTURED+BROKEN,TRACE OF BLACK BITUMEN IMPREGNATION,CLAY MINERAL AND QUARTZ CEMENT; Alteration - CLAY MINERALS Leg : 64 Top/Bottom Interval(mm): 60/ 90 Describer: Saunders, A. Hole: 475 Top of Core Depth(m) : 167.50 Rock Type: SEDIMENTARY Core: 19 Sample Midpoint(m) : 167.58 Sect/Pc #: 1/PCE 2 ROCK = QUARTZ-FELDSPAR PORPHYRY ROCK MAY HAVE BEEN A TUFF ALTHOUGH NO LINEATION CAN BE SEEN; Texture: PORPHYRITIC,RECRYSTALLIZED GROUNDMASS; OTHER PEBBLE IN CONGLOMERATE* Phenocrysts- QUARTZ ( 10%) Size(mm): 0.4-2.5 Morphology: SUBHEDRAL-EUHEDRAL SLIGHTLY ROUNDED; FELDSPAR ( 15%) Size(mm): 0.5-3 Morphology: SUBHEDRAL ORTHOCLASE? + ALBITE,XTLS OFTEN IN GLOMEROCRYSTIC AGGREGATES* Groundmass - QUARTZ GROUNDMASS COMPRISES RECRYSTALLIZED QUARTZ + FEL; FELDSPAR GROUNDMASS COMPRISES RECRYSTALLIZED QUARTZ + FEL; CHLORITE ( 5%) Size(mm): <0.1 Morphology: FIBROUS IDENTITY QUESTIONABLE* Alteration - EPIDOTE ( 5%) Replacing: FEL IDENTITY AND PERCENTAGE ARE QUESTIONABLE* Leg : 64 Top/Bottom Interval(mm): 120/ 150 Describer: Saunders, A. Hole: 475 Top of Core Depth(m) : 167.50 Rock Type: TUFF Core: 19 Sample Midpoint(m) : 167.64 Sect/Pc #: 1/PCE 3 ROCK = RHYOLITIC IGNIMBRITE OR RECRYSTALLIZED FLOW BANDED RHYOLITE; Texture: PORPHYRITIC,IGNIMBRITIC,RECRYSTALLIZED; Where sampled: OTHER COBBLE IN CONGLOMERATE* Phenocrysts- FELDSPAR ( 10%) Size(mm): 1-2 Morphology: SUBHEDRAL ALBITE OR ORTHOCLASE,SERICITIZED,LYING IN FINE GRAINED GROUNDMASS WHICH SHOWS DEFLECTION AROUND PHENOS* Groundmass - QUARTZ FELDSPAR OPAQUE MINERALS COMBINATION STRONGLY BANDED FINE GRAINED GROUNDMASS COMPRISING QUARTZ + FEL + OP.MINS,BANDING ESPECIALLY WELL ILLUSTRATED BY OP.MINS,FLOW OF GROUNDMASS DIVERTED AROUND PHENOS* Leg : 64 Top/Bottom Interval(mm): 320/ 350 Describer: Saunders, A. Hole: 475 Top of Core Depth(m) : 167.50 Rock Type: IGNEOUS Core: 19 Sample Midpoint(m) : 167.84 Sect/Pc #: 1/PCE 7 ROCK = RECRYSTALLIZED RHYOLITIC GLASS; Texture: MODERATELY PORPHYRITIC GROUNDMASS IS PRACTICALLY AMORPHOUS* Phenocrysts- ORTHOCLASE ( <3%) Size(mm): <2 Morphology: SUBHEDRAL Groundmass - QUARTZ ( 80%) GROUNDMASS IS VERY FINE-GRAINED (PROBABLY QUENCHED OR RECRYSTALLIZE),QUARTZ ORE RICH (PROBABLY 80%)* Alteration - ( 10%) Location: IN AGGREGATES FIBROUS ACICULAR CLUSTERS,NOT KNOWN WHAT IS BEING REPLACED* Leg : 64 Top/Bottom Interval(mm): 430/ 470 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 167.50 Rock Type: TUFF Core: 19 Sample Midpoint(m) : 167.95 Sect/Pc #: 1/PCE 9 ROCK = RHYOLITE TUFF ENCODED FROM THE ICD,FINE-GRAINED RECRYSTALLIZED GROUNDMASS,CHLORITE ALTERATION,QUARTZ ALTERATION, WEATHERED RIND WITH IRON OXIDES,MANY GRAINS SHOW SERICITIZATION,SOME FAINT GRAIN IMBRICATION; Phenocrysts- ALBITE Size(mm): 1-2 Morphology: SUBHEDRAL ORTHOCLASE Size(mm): 1-2 Morphology: SUBHEDRAL PLAGIOCLASE Size(mm): 1-2 Leg : 64 Top/Bottom Interval(mm): 100/ 170 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 177.00 Rock Type: SEDIMENTARY Core: 20 Sample Midpoint(m) : 177.14 Sect/Pc #: 1/ ROCK = POLYGENETIC CONGLOMERATE ENCODED FROM THE ICD,CLASTS ARE ANGULAR ROCK FRAGMENTS TO BRECCIA (1-10MM),INCLUDE MICA-SCHIST+ QUARTZITE+GRANITE+LARGE QUARTZ-MICA FRAGMENTS, GRAIN SUPPORTED,MATRIX SILICEOUS(CLAY+QUARTZ),SOME MICA ENVELOPES,OP.MINS 5%* Leg : 64 Top/Bottom Interval(mm): 450/ 520 Describer: Saunders, A. Hole: 475 Top of Core Depth(m) : 177.00 Rock Type: TUFF Core: 20 Sample Midpoint(m) : 177.49 Sect/Pc #: 1/PCE 8 ROCK = RHYOLITIC IGNIMBRITE; Texture: PORPHYRITIC,FLOWBANDED WITH FIAMME FIAMME ARE QUESTIONABLE; Where sampled: OTHER COBBLE IN CONGLOMERATE* Phenocrysts- FELDSPAR ( 10%) Size(mm): 1 Morphology: SUBHEDRAL ORTHOCLASE OR ALBITE,SERICITIZED; QUARTZ ( 5%) Size(mm): 1 Morphology: SUBHEDRAL,EMBAYED Groundmass - MATRIX VERY FINE-GRAINED MATRIX OF QUARTZ + FEL + MINOR MICAS + OP.MINS,STRONGLY FLOW-BANDED, RECRYSTALLIZED GLASS STREAKS WERE PROBABLY FIAMME; QUARTZ FELDSPAR MICA OPAQUE MINERALS Alteration - EPIDOTE ( 5%) Location: RANDOM Leg : 64 Top/Bottom Interval(mm): 550/ 600 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 177.00 Rock Type: IGNEOUS Core: 20 Sample Midpoint(m) : 177.58 Sect/Pc #: 1/PCE 9 ROCK = VOLCANIC ROCK ROCK NAME IS TRACHYTE?,ENCODED FROM THE ICD; Texture: PORPHYRITIC; Phenocrysts- KFELDSPAR ( 30%) PLAGIOCLASE-K-FELDSPAR,PHENOS AND FRAGMENTS; PYROXENE ( 5%) Morphology: EUHEDRAL-SUBHEDRAL ALTERED; SPHENE ( 3%) QUARTZ ( 10%) Size(mm): 1 Groundmass - DEVITRIFIED GLASS ( 40%) LIGHT BROWN,PARTLY DEVITRIFIED,MUCH ISOTROPIC* Leg : 64 Top/Bottom Interval(mm): 700/ 730 Describer: Fornari, D. Hole: 475 Top of Core Depth(m) : 177.00 Rock Type: IGNEOUS Core: 20 Sample Midpoint(m) : 177.72 Sect/Pc #: 1/ ROCK = GLASSY VOLCANIC EFFUSIVE 50% EUHEDRAL TO FRAGMENTARY TO SUBHEDRAL TO GLOBUAR FELDSPAR (PLAG AND K-FELDSPAR) AND QUARTZ WITH 50% LIGHT BROWN ISOTOPIC GROUNDMASS,SOME DEVITRIFICATION TO CHLORITE(?),ENCODED FROM THE ICD* |
Cite as: Deep Sea Drilling Project (1989): Archive of Core and Site/Hole Data and Photographs from the Deep Sea Drilling Project (DSDP). National Geophysical Data Center, NOAA. doi:10.7289/V54M92G2 [access date]
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