Leg : 60 Top/Bottom Interval(mm): 170/ 180 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 36.50 Rock Type: TUFF Core: 5 Sample Midpoint(m) : 36.68 Sect/Pc #: 1/ ROCK = VITRIC TUFF ALTERED XTL-LITHIC VITRIC TUFF; Where sampled: PEBBLE IN SEDIMENT* Phenocrysts- PLAGIOCLASE ( 5%) Size(mm): 0.1-0.4 Morphology: ANGULAR CRYSTALS-NOT PHENOS; CLINOPYROXENE ( 3%) Size(mm): 0.1-0.4 Morphology: ANGULAR GREENISH,CRYSTALS-NOT PHENOS; QUARTZ ( 1%) CRYSTALS-NOT PHENOS; OTHER ( 10%) LITHIC FRAGMENTS,INCLUDES PLAG-CPX HYALOPILITIC BASALT FRAGMENTS* Groundmass - GLASS GLASSY MATRIX ALTERED TO CLAYS,SOME VITRIC GRAINS ALTERED TO PALAGONITE(PRIOR TO INCORPORATION)* Alteration - CLAY MINERALS Replacing: GLASS,PALAGONITE FERROUS OXIDE Location: PERVASIVE RED COLOR* Leg : 60 Top/Bottom Interval(mm): 240/ 250 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 36.50 Rock Type: TUFF Core: 5 Sample Midpoint(m) : 36.75 Sect/Pc #: 1/ ROCK = VITRIC TUFF ALTERED XTL-VITRIC TUFF* Groundmass - GLASS MOST OF ROCK,ALTERED TO CLAYS + FE-OXIDES; COMBINATION ( 10%) Size(mm): 0.05-0.15 INCLUDES ANGULAR FRAGMENTS OF PLAG + CPX + QUARTZ* Alteration - CLAY MINERALS Replacing: GLASS FERROUS OXIDE Replacing: GLASS RED COLOR* Leg : 60 Top/Bottom Interval(mm): 120/ 130 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 55.50 Rock Type: IGNEOUS Core: 7 Sample Midpoint(m) : 57.72 Sect/Pc #: CC/PCE 1 ROCK = APHYRIC BASALT ALTERED; Texture: HYALOPILITIC,SPHERULITIC; Where sampled: COBBLE IN SEDIMENTS* Groundmass - GLASS ( 45%) DEVITRIFIED,NOW ALTERED TO RED-ORANGE CLAYS; PLAGIOCLASE ( 15%) Size(mm): 0.1-0.5 Morphology: ACICULAR MICROLITES AND SOME INTERSTITIAL; MAGNETITE ( 1-2%) Size(mm): TO 0.03 Morphology: SKELETAL ABUNDANT SKELETAL CRYSTALLITES AND MORE LARGE IRREGULAR GRAINS UP TO 0.03 MM* Alteration - CLAY MINERALS ( 40%) Location: GENERAL Replacing: GLASS CLEAR COLOR* Vesicles - Size(mm): 1.0-5.0 Percent: 5 Location: ONE SIDE OF Filling: NONE Shape: SUB-ROUNDED Location: SECTION ONLY A FEW ARE PRESENT BUT THEY ARE LARGE* Leg : 60 Top/Bottom Interval(mm): 120/ 131 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 55.50 Rock Type: IGNEOUS Core: 7 Sample Midpoint(m) : 57.72 Sect/Pc #: CC/PCE 2 ROCK = PLAGIOCLASE SPARSELY PHYRIC BASALT ALTERED; Texture: HYALOPILITIC; Where sampled: COBBLE IN SEDIMENTS* Phenocrysts- PLAGIOCLASE ( TR%) Size(mm): 0.1-0.2 Morphology: TABULAR Groundmass - GLASS ( 40%) NOW ALTERED TO CLAYS + REDDISH AMORPHOUS MATERIAL (ONCE WAS SPHERULITIC CPX); PLAGIOCLASE ( 10%) Size(mm): 0.01-0.1 Morphology: ACICULAR NEEDLES CLINOPYROXENE ( TR%) TINY XTLS-MANY ALTERED TO CLAYS* Alteration - CLAY MINERALS ( 45%) Location: MOST PLACES Replacing: GLASS,CPX FERROUS OXIDE ( 5%) Replacing: GLASS,CPX RED COLOR,CLAY + FE.OX REPLACE SOME CPX* Vesicles - Percent: 5 Leg : 60 Top/Bottom Interval(mm): 350/ 370 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 65.00 Rock Type: IGNEOUS Core: 8 Sample Midpoint(m) : 65.36 Sect/Pc #: CC/ ROCK = ALTERED HYALOCLASTITE; Where sampled: AT CONTACT WITH SEDIMENTS UNCONFORMITY(?)* Phenocrysts- PLAGIOCLASE ( 1%) Size(mm): 0.1X0.4 Morphology: TABULAR CLINOPYROXENE ( TR%) Size(mm): 1.0-1.5 Groundmass - GLASS ( 84%) ANGULAR GREEN ALTERED GLASS FRAGMENTS UP TO 5.0MM IN DIAMETER IN CRUSHED GLASS MATRIX,GREEN GLASS ALTERATION IS A FAINTLY BIREFRINGENT MATERIAL; CLINOPYROXENE ( 10%) Size(mm): 0.01-0.1 Morphology: ACICULAR MICROLITES IN ALTERED GLASS; PLAGIOCLASE ( 5%) Size(mm): 0.1-0.2 Morphology: ACICULAR MICROLITES IN ALTERED GLASS* Alteration - CLAY MINERALS Location: THROUGHOUT Replacing: GLASS ZEOLITE ( 1-2%) 10% CEMENTING MASS WITH CLAY,BETWEEN ALTERED GLASS FRAGMENTS; FERROUS OXIDE Location: SCATTERED Replacing: GLASS RED COLOR* Vesicles - Size(mm): 0.2-0.4 Percent: 2 Location: GLASS FRAGS Filling: ZEOLITES,CLAYS Shape: ROUND Leg : 60 Top/Bottom Interval(mm): 60/ 80 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 74.50 Rock Type: IGNEOUS Core: 9 Sample Midpoint(m) : 74.57 Sect/Pc #: CC/ ROCK = PLAGIOCLASE SPARSELY PHYRIC BASALT ALTERED,TALUS(?); Texture: HYALOPILITIC* Phenocrysts- PLAGIOCLASE ( 1%) Size(mm): 0.1X0.4 GROUPED AS GLOMEROCRYSTS* Groundmass - GLASS ( 50%) ONCE SPHERULITIC,NOW ALTERED TO CLAYS + FE-OXIDES; PLAGIOCLASE ( 15%) Size(mm): 0.01X0.4 Morphology: ACICULAR ALSO HAVE SMALLER GRAINS OF 0.01X0.2MM; MAGNETITE ( 1%) Size(mm): 0.01-0.05 Morphology: CUBIC,SKELETAL Alteration - CLAY MINERALS ( 30%) Replacing: GLASS PALE GREEN COLOR* Vesicles - Size(mm): 0.1-0.3 Percent: 3 Location: SCATTERED Filling: NONE Shape: IRREGULAR- Shape: ROUND Leg : 60 Top/Bottom Interval(mm): 120/ 130 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 74.50 Rock Type: IGNEOUS Core: 9 Sample Midpoint(m) : 74.63 Sect/Pc #: CC/ ROCK = PLAG-CPX SPARSELY PHYRIC BASALT; Texture: HYALOPILITIC; Where sampled: PILLOW INTERIOR AREA UNCERTAIN* Phenocrysts- PLAGIOCLASE ( 1%) Size(mm): 0.5-0.7 APPROX COMP AN55; CLINOPYROXENE ( TR%) Groundmass - GLASS ( 72%) MESOSTASIS-PARTIALLY ALTERED,CRYPTOCRSTALLINE-WITH SPHERULITIC CPX(?)+FE.OX PARTLY ALTERED TO CLAY; PLAGIOCLASE ( 20%) Size(mm): 0.05-0.1 Morphology: ACICULAR-SKELETAL CLINOPYROXENE ( 1-2%) OBSCURE IN MESOSTASIS; MAGNETITE ( 1%) Size(mm): 0.001-0.02 Morphology: CUBIC,BLOCKY TWO TYPES-BRANCHING AND TRELLICED IN MESOSTASIS, CUBIC AND BLOCKY ELSEWHERE* Alteration - CLAY MINERALS Location: LINE VESICLES Replacing: GLASS,FE.OXIDES VERY DISPERSED,FE.OX PARTLY ALTERED TO GREEN CLAYS (MAYBE SOME BROWN CLAYS)* Vesicles - Size(mm): 0.1-1.0 Percent: 5 Location: SCATTERED Filling: NONE Shape: ROUND FINER GRAINED NEXT TO VESICLES MORE SPHERULITIC* Leg : 60 Top/Bottom Interval(mm): 250/ 270 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 84.00 Rock Type: UNIDENTIFIED Core: 10 Sample Midpoint(m) : 84.26 Sect/Pc #: CC/ ROCK = QUARTZ-CEMENTED BASALT BRECCIA IN PLACE(?) TALUS(?),THIN SECTION CONSISTS OF ONE LARGE BASALTIC FRAGMENT + SEVERAL SMALLER ONES; Texture: SPHERULITIC FORMERLY SPHERULITIC IN BASALT FRAGMENTS* Groundmass - MICROCRYST GROUNDMASS ( 95%) INCLUDES ALTERED DEVITRIFIED GLASS AND ABUNDANT CLAY PSEUDOMORPHS AFTER SPHERULITIC CPX; QUARTZ ( 40%) Size(mm): 0.01-0.02 ENCASES BASALT FRAGMENTS AS A CRYSTALLINE QUARTZ CEMENT,ALSO REPLACES BASALT FRAGMENTS; PLAGIOCLASE ( 5%) Size(mm): 0.01-0.02 Morphology: ACICULAR NEEDLES PYRITE ( 3%) CONTAINED WITHIN THE QUARTZ VEINS; MAGNETITE ( TR%) Morphology: SKELETAL ONE OR TWO LARGE SKELETAL FRAGMENTS* Alteration - QUARTZ ( 40%) Location: VEINS, Replacing: GLASS Location: GROUNDMASS FORMS XTLS IN VEINS(0.05 IN DIAMETER),ALSO PRESENT AS A SECONDARY MINERAL IN BASALT GROUNDMASS; PYRITE ( 3%) ASSOCIATED WITH QUARTZ VEINS* CLAY MINERALS Replacing: CPX,GLASS Vesicles - Percent: 0 Leg : 60 Top/Bottom Interval(mm): 250/ 260 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 93.50 Rock Type: IGNEOUS Core: 11 Sample Midpoint(m) : 93.76 Sect/Pc #: 1/PCE 5 ROCK = PLAG-CPX SPARSELY PHYRIC BASALT; Texture: HYALOPILITIC,GLASSY,SPARSELY PHYRIC; Where sampled: NEXT TO GLASSY MARGIN PEBBLE AMONG METABASALTS RECOVERED IN TALUS OR BRECCIA* Phenocrysts- PLAGIOCLASE ( 1%) Size(mm): 0.1-0.4 Morphology: TABULAR APPROX COMP AN50-55,SOME WITH ANOMALOUSLY LOW 2VZ- OF ABOUT 30,LABRADORITE; CLINOPYROXENE ( 1%) Size(mm): 0.3-0.8 2VX OF 80,PALE GREEN AND FAINTLY PLEOCHROIC* Groundmass - PLAGIOCLASE ( 15%) Size(mm): 0.1-0.4 Morphology: ACICULAR-SKELETAL ENCLOSES GLASS,SOME PLAG PHANTOMS-XTL OUTLINES PRESENT BUT ONLY COLOR OF GLASS IN PLANE LIGHT; CLINOPYROXENE ( 5%) Size(mm): 0.01-0.1 Morphology: ACICULAR MAGNETITE ( TR%) Size(mm): TO 0.01 Morphology: CUBIC GLASS TWO TYPES-ONE HAS RICH RED-BROWN COLOR AND SURROUNDS GROUNDMASS XTLS AND THE OTHER IS PALE YELLOW AND SURROUNDS VESICLES,SECOND TYPE IS PERHAPS A KIND OF PALAGONITE(?)* Alteration - CLAY MINERALS IN YELLOW GLASS NEAR VESICLES,FAINTLY BIREFRINGENT* Vesicles - Size(mm): 0.1-0.5 Percent: 5 Location: SCATTERED Filling: NONE Shape: ROUND TO Shape: IRREGULAR SURROUNDED WITH GLASS* Leg : 60 Top/Bottom Interval(mm): 290/ 310 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 93.50 Rock Type: METAMORPHIC Core: 11 Sample Midpoint(m) : 93.80 Sect/Pc #: 1/PCE 6 ROCK = QUARTZ-AMPHIBOLE-PLAGIOCLASE METABASALT; Texture: GRANO-POIKILOBLASTIC PRIOR SUBOPHITIC TEXTURES* Groundmass - AMPHIBOLE ( 50%) AFTER CPX,YELLOWISH-GREEN AND FAINTLY PLEOCHROIC; PLAGIOCLASE ( 38%) Morphology: RELICT MUCH IS RELICT FROM PRIOR SUBOPHITIC TEXTURES; QUARTZ ( 10%) IN PATCHES BETWEEN THE FELDSPARS AND AMPHIBOLES; CLINOPYROXENE ( 1%) Morphology: RELICT TRACES OF RELICT CPX IN THE AMPHIBOLE; MAGNETITE ( 1%) Size(mm): 0.01-0.04 Morphology: SKELETAL,CUBIC MANY QUARTZ-ALBITE(?) INTERGROWTHS* Alteration - AMPHIBOLE ( 50%) Replacing: CPX GREEN,SOME FAINTLY PLEOCHROIC; QUARTZ ( 10%) Leg : 60 Top/Bottom Interval(mm): 0/ 0 Describer: Natland, J. Hole: 460A Top of Core Depth(m) : 99.50 Rock Type: METAMORPHIC Core: C 1 Sample Midpoint(m) : 99.50 Sect/Pc #: / ROCK = QUARTZ-AMPHIBOLE-PLAGIOCLASE METABASALT THE ROCK IS A SILICIFIED BASALT,UPPER GREENSHIST LOWER AMPHIBOLE FACIES; Texture: GRANO-POIKILOBLASTIC SOME PRIOR SUBOPHITIC TEXTURES* Phenocrysts- CLINOPYROXENE ( TR%) Size(mm): TO 0.2 Morphology: RELICT,GRANULAR Groundmass - AMPHIBOLE ( 60%) AFTER GLASS AND CPX; PLAGIOCLASE ( 32%) Size(mm): 0.1-0.5 Morphology: ACICULAR,RELICT MUCH IS RELICT FROM PRIOR SUBOPHITIC TEXTURES; QUARTZ ( 7%) QUARTZ XTLS PERMEATE THE GROUNDMASS AND FILL OR PARTLY FILL SOME VESICLES,AFTER GLASS; CLINOPYROXENE ( TR%) Morphology: RELICT SURROUNDED BY AMPH,ALTERED TO CLAYS; GLASS ALTERED TO CLAYS+QUARTZ+AMPH* Alteration - AMPHIBOLE ( 60%) Replacing: GLASS,CPX QUARTZ ( 7%) Location: THROUGHOUT Replacing: FILL VESICLES,GLASS CARBONATE ( 1%) Location: IN VESICLES Vesicles - Percent: 0 VESICLES,IF THEY WERE PRESENT HAVE BEEN COMPLETELY OBLITERATED BY METAMORPHISM* |
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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