Leg : 60 Top/Bottom Interval(mm): 1180/1200 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: IGNEOUS Core: 1 Sample Midpoint(m) : 2.69 Sect/Pc #: 2/ ROCK = FELDSPATHIC GABBRO; Texture: GRANOBLASTIC TEX UNCERTAIN,SLIGHT INDICATION OF FOLIATION* Groundmass - PLAGIOCLASE ( 40%) Size(mm): 0.5-1.0 APPROX COMP AN60,FRESH; CLINOPYROXENE ( 40%) Size(mm): 0.3-1.0 FRESH,WITH EXSOLUTION LAMELLAE OF OPX; ORTHOPYROXENE ( 20%) Size(mm): 0.3-1.0 FRESH,WITH CPX EXSOLUTION LAMELLAE* Alteration - CLAY MINERALS SEVERAL FRACTURES RUNNING THROUGH SLIDE BEARING CLAYS(?) BUT OTHERWISE SECONDARY MINS ARE ABSENT* Leg : 60 Top/Bottom Interval(mm): 340/ 370 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: UNIDENTIFIED Core: 1 Sample Midpoint(m) : 3.36 Sect/Pc #: 3/ ROCK = POLYMICT BRECCIA SECTION CONSISTS OF TWO CLASTS,ONE LARGE OPX-CPX PLAG GABBRO(2.0X2.5CM) + ONE BASALTIC(1.0X0.5CM) + FINE-GRAINED GRANULATED GABBROIC MATERIAL AS A MATRIX,GABBROIC CLAST HAS CUMULATE TEX AND COMP OF PLAG(45%) + CPX(30%) + OPX(10%) + ONE LARGE QUARTZ VEIN(0.5CM WIDE),BASALTIC CLAST CONSISTS OF FRESH PLAG(30%) + INTERSTITIAL GLASS(27%) + VESICLES(30%) + CPX(10%) + MAGN(3%),BRECCIA MATRIX INCLUDES ZEOLITES + AMPHS + PYXS + ANTIGORITE + GABBROIC FRAGS + VERY FINE GRAINED COMMINUTED MATERIAL* Alteration - TALC Replacing: OPX CHLORITE Replacing: OPX CLAY MINERALS Replacing: CPX QUARTZ Leg : 60 Top/Bottom Interval(mm): 470/ 480 Describer: Sharaskin, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: IGNEOUS Core: 1 Sample Midpoint(m) : 3.48 Sect/Pc #: 3/ ROCK = METABASALT; Texture: PSEUDOSPHERULITIC-PSEUDOHYALOPILITIC; Where sampled: COBBLE IN SEDIMENTS* Phenocrysts- PLAGIOCLASE ( TR%) Size(mm): TO 0.15 Morphology: LATHS ONLY SINGLE GRAIN IN THE SLIDE; CLINOPYROXENE ( TR%) Size(mm): TO 0.17 Morphology: SKELETAL APPROX COMP AUGITE,TWO GRAINS IN THE SLIDE* Groundmass - GLASS TOTALLY ALTERED,ORIGINALLY VESICULAR+SPHERULITIC+ HYALOPILITIC* Alteration - CLAY MINERALS ( 97%) Location: THROUGHOUT QUARTZ ( 3%) Location: VESICLES AND Location: MICROXLN ZEOLITE ( 3%) Location: VEINS VEINS UP TO 0.5MM THICK; EPIDOTE ( <1%) Location: MESOSTASIS TINY GRAINS IN MICROXLN* Vesicles - Size(mm): 0.01-0.5 Percent: 3 Location: THROUGHOUT Filling: QUARTZ Shape: IRREGULAR Leg : 60 Top/Bottom Interval(mm): 740/ 750 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: IGNEOUS Core: 1 Sample Midpoint(m) : 3.75 Sect/Pc #: 3/ ROCK = APHYRIC BASALT; Texture: INTERSERTAL* Phenocrysts- PLAGIOCLASE ( TR%) Size(mm): TO 0.5 Morphology: SUBHEDRAL APPROX COMP AN70-80,UNALTERED; CLINOPYROXENE ( TR%) Size(mm): 0.2-0.5 Morphology: EUHEDRAL APPROX COMP UNCERTAIN,FRESH LOOKING* Groundmass - PLAGIOCLASE ( 20%) Size(mm): 0.1-1.0 Morphology: BLOCKY-ACICULAR APPROX COMP AN65; CLINOPYROXENE ( 15%) Size(mm): 0.1-0.3 Morphology: ACICULAR-SKELETAL MAGNETITE ( 2%) Size(mm): 0.01-0.13 Morphology: SUBHEDRAL Alteration - CLAY MINERALS ( 53%) Location: MESOSTASIS, Location: VESICLES Vesicles - Size(mm): 0.05-0.5 Percent: 10 Location: THROUGHOUT Filling: CLAY.MINS Shape: IRREGULAR Leg : 60 Top/Bottom Interval(mm): 850/ 860 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: IGNEOUS Core: 1 Sample Midpoint(m) : 3.86 Sect/Pc #: 3/ ROCK = FELDSPATHIC GABBRO PART OF BRECCIA; Texture: CUMULATE* Groundmass - PLAGIOCLASE ( 70%) Size(mm): 0.1-1.0 APPROX COMP AN55,GENERALLY IN ADCUMULUS GROWTH TEXTURE,GENERALLY NOT ZONED,UNALTERED; CLINOPYROXENE ( 25%) Size(mm): 0.1-1.0 GENERALLY INTERSTITIAL,MOSTLY ALTERED TO URALITE; QUARTZ ( 3%) Size(mm): 0.1-0.5 IN DISCRETE GRAINS AND IN VEINS WITH CHLORITE; OTHER ( 2%) INCLUDES SMALL AMOUNT OF POLYMICT IGNEOUS BRECCIA MATERIAL ADHERED TO ONE SIDE OF FRAGMENT; ORTHOPYROXENE MAY HAVE BEEN PRESENT BEFORE URALITE ALTERATION* Alteration - URALITE Replacing: CPX URALITE Replacing: OPX CHLORITE Location: IN VEINS QUARTZ ( 3%) Location: VEINS Leg : 60 Top/Bottom Interval(mm): 1210/1230 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: METAMORPHIC Core: 1 Sample Midpoint(m) : 4.22 Sect/Pc #: 3/ ROCK = META-MICRODIABASE; Texture: DIABASIC* Groundmass - AMPHIBOLE ( 50%) Size(mm): 0.1-0.5 Morphology: ANHEDRAL,FIBROUS ACTINOLITE(?),REPLACING PYX; PLAGIOCLASE ( 30%) Morphology: TABULAR-BLOCKY APPROX COMP AN50,PARTLY REPLACED BY CLAYS; QUARTZ ( 15%) Size(mm): 0.1-0.5 SOMETIMES IN MICROGRAPHIC INTERGROWTHS WITH FELDSPARS; MAGNETITE ( 5%) Size(mm): 0.05-0.3 Morphology: SKELETAL-SUBHEDRAL USUALLY ASSOCIATED WITH SPHENE AND AMPH* Alteration - SPHENE ( TR%) AMPHIBOLE Replacing: PYX CLAY MINERALS Replacing: PLAG Leg : 60 Top/Bottom Interval(mm): 100/ 110 Describer: Sharaskin, A. Hole: 461A Top of Core Depth(m) : 0.00 Rock Type: METAMORPHIC Core: 1 Sample Midpoint(m) : 6.00 Sect/Pc #: CC/ ROCK = METABASALT; Texture: PSEUDOHYALOPILITIC-PSEUDOSPHERULITIC; Where sampled: COBBLE IN SEDIMENTS* Groundmass - MICROCRYST GROUNDMASS ( 70%) TOTALLY ALTERED TO CLAYS; PLAGIOCLASE ( 25%) Size(mm): TO 0.2 MAGNETITE ( 5%) Size(mm): 0.01-0.03 CLINOPYROXENE ( <1%) Size(mm): TO 0.1 Morphology: RELICTS RELICTS OF CRYSTALLITES* Alteration - CLAY MINERALS ( 97%) Location: VESICLES, Replacing: EVERYTHING Location: MESOSTASIS CHLORITE ( 3%) Replacing: CPX PSEUDOMORPHS AFTER CPX GRAINS* Vesicles - Size(mm): 0.03-0.5 Percent: 7 Location: THROUGHOUT Filling: CLAY.MIN Shape: ROUND SOME VERY LARGE IRREGULAR VESICLES ARE PRESENT* Leg : 60 Top/Bottom Interval(mm): 320/ 340 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: METAMORPHIC Core: 2 Sample Midpoint(m) : 6.33 Sect/Pc #: 1/ ROCK = METABASALT MICRODIABASE IS ALTERATE ROCK TYPE; Texture: SUBOPHITIC COARSE-GRAINED BASALT OR FINE-GRAINED MICRODIABASE* Groundmass - PLAGIOCLASE ( 30%) Size(mm): 0.1-0.6 Morphology: TABULAR-BLOCKY APPROX COMP AN55,PARTLY ALTERED; AMPHIBOLE ( 30%) Size(mm): 0.1-0.7 Morphology: ANHEDRAL GENERALLY FIBROUS,REPLACING CPX(?); MICROCRYST GROUNDMASS ( 20%) INTERGROWTH OF QUARTZ + FELDSPAR,HIGHLY ALTERED; QUARTZ ( 10%) Size(mm): 0.1-0.5 OFTEN FRACTURED,OCCUR THROUGHOUT ROCK; MAGNETITE ( 8%) Size(mm): 0.05-0.3 ASSOCIATED WITH AMPHIBOLE* Alteration - EPIDOTE ( 2%) Location: SCATTERED AMPHIBOLE Replacing: CPX Leg : 60 Top/Bottom Interval(mm): 340/ 350 Describer: Sharaskin, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: METAMORPHIC Core: 2 Sample Midpoint(m) : 6.35 Sect/Pc #: 1/ ROCK = METABASALT AMPHIBOLITE; Texture: POIKILOBLASTIC* Groundmass - PLAGIOCLASE ( 60%) POIKILOBLASTS OF PLAG(ANDESINE)FORMS GRANOBLASTIC AGGREGATES TOGETHER WITH QUARTZ AND INCLUDES MAGN GRAINS AND AMPH NEEDLES AND PLAG LATHS,FOLIATION IS VERY WEAK,SOME EPIDOTE IS ALSO PRESENT; HORNBLENDE ( 25%) QUARTZ ( 7%) MAGNETITE ( 7%) Alteration - EPIDOTE AMPHIBOLE Leg : 60 Top/Bottom Interval(mm): 850/ 860 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: IGNEOUS Core: 2 Sample Midpoint(m) : 6.86 Sect/Pc #: 1/ ROCK = SIDEROMELANE; Texture: HOLOHYALINE* Groundmass - GLASS ( 98%) MOSTLY DEVITRIFIED(STILL ISOTROPIC) AND PARTLY ALTERED TO CLAYS IN VESICLES AND ALONG VEINS, FRESH; PLAGIOCLASE ( 1%) Size(mm): 0.01-0.2 Morphology: ACICULAR APPROX COMP UNCERTAIN* Alteration - CLAY MINERALS Location: VESICLES, Replacing: GLASS Location: ALONG VEINS Leg : 60 Top/Bottom Interval(mm): 950/ 960 Describer: Sharaskin, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: METAMORPHIC Core: 2 Sample Midpoint(m) : 6.96 Sect/Pc #: 1/ ROCK = METABASALT; Texture: PSEUDOSUBOPHITIC; Where sampled: COBBLE IN DRILLING BRECCIA* Phenocrysts- PLAGIOCLASE ( TR%) Size(mm): TO 0.2 Morphology: EUHEDRAL APPROX COMP AN70,GLOMEROCRYSTS; CLINOPYROXENE ( TR%) Size(mm): TO 0.2 Morphology: EUHEDRAL APPROX COMP AUGITE,SOMETIMES GLOMEROCRYSTS* Groundmass - MICROCRYST GROUNDMASS ( 67%) INCLUDES PYX MICROLITES; PLAGIOCLASE ( 25%) Size(mm): TO 0.3 APPROX COMP UNCERTAIN; QUARTZ ( 5%) Size(mm): 0.01-0.3 SECONDARY,SEPARATE GRAINS AND AGGREGATES; MAGNETITE ( 3%) Size(mm): 0.01-0.1 Alteration - CLAY MINERALS ( 90%) Location: MESOSTASIS QUARTZ ( 5%) Location: MESOSTASIS, Location: VESICLES EPIDOTE ( 1-3%) Location: MESOSTASIS Vesicles - Size(mm): 0.05-1.0 Percent: 10-15 Location: THROUGHOUT Filling: QUARTZ,MINOR Shape: SUBROUND- Filling: CLAY.MINS Shape: IRREGULAR Leg : 60 Top/Bottom Interval(mm): 1050/1070 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: IGNEOUS Core: 2 Sample Midpoint(m) : 7.06 Sect/Pc #: 1/ ROCK = GABBRO; Texture: GRANOBLASTIC* Groundmass - PLAGIOCLASE ( 45%) Morphology: EUHEDRAL-SUBHEDRAL APPROX COMP AN55 ZONED TO AN25 ON RIMS,INCIPIENTLY ALTERED TO SERICITE; AMPHIBOLE ( 35%) Size(mm): 0.3-2.0 Morphology: ANHEDRAL ACTINOLITE-TREMOLITE FILLING INTERSTITIAL AREAS BETWEEN PLAG,OFTEN COMPLEXLY TWINNED,PROBABLY REPLACEMENT OF CPX; QUARTZ ( 8%) Morphology: ANHEDRAL INTERSTITIAL,SOMETIMES IN MICROGRAPHIC INTERGROWTHS WITH FELDSPAR; MAGNETITE ( 5%) Size(mm): TO 1.0 Morphology: EQUANT GENERALLY LARGE(1.0MM)GRAINS; CHLORITE ( 5%) Size(mm): <0.5 IN SMALL CLUMPS,PARTLY ALTERATION PRODUCT OF AMPH; CLINOPYROXENE ( 2%) REMNANTS MOSTLY REPLACED BY AMPH; EPIDOTE ( TR%) AS ALTERATION PRODUCT OF AMPH; SPHENE ASSOCIATED WITH LARGE MAGN GRAINS* Alteration - AMPHIBOLE Replacing: CPX SERICITE Replacing: PLAG CHLORITE Replacing: AMPH EPIDOTE Replacing: AMPH Leg : 60 Top/Bottom Interval(mm): 150/ 160 Describer: Meijer, A. Hole: 461A Top of Core Depth(m) : 6.00 Rock Type: METAMORPHIC Core: 2 Sample Midpoint(m) : 7.59 Sect/Pc #: CC/ ROCK = EPIDOSITE OBSERVER STATES THIS IS A WEIRD SLIDE* Groundmass - EPIDOTE NEARLY PURE EPIDOTE OR MINERAL OF SAME GROUP,IN A FINE GRAINED MASS,LESSER AMOUNT OF THE MINERAL WITH VERY LOW BIREFRINGENCE AND UNDULATORY EXTINCTION-POSSIBLY A ZEOLITE* Alteration - EPIDOTE IDENTITY UNCERTAIN; ZEOLITE IDENTITY UNCERTAIN* |
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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