Leg : 60 Top/Bottom Interval(mm): 90/ 130 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 256.50 Rock Type: IGNEOUS
Core: 28 Sample Midpoint(m) : 256.61 Sect/Pc #: 1/PCE 2
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: HYALOPILITIC;
Where sampled: NEXT TO GLASSY MARGIN
Phenocrysts- CLINOPYROXENE ( 6%)
Size(mm): 0.1-1.0 Morphology: EUHEDRAL,STUBBY
UNALTERED MICROPHENOCRYSTS;
ORTHOPYROXENE ( 1%)
Size(mm): 0.1-1.0
INTERGROWN WITHIN THE CPX XTLS*
Groundmass - GLASS ( 43%)
QUENCHED TO GLASS,PYX + ORE + PLAG,
R.I. OF GLASS LEQ BALSAM;
CLINOPYROXENE ( 10%)
Size(mm): 0.004-0.1 Morphology: STUBBY TO EUHEDRAL
UNALTERED*
Alteration - CLAY MINERALS ( 10%)
Location: AROUND Replacing: GLASS
Location: VESICLES
PERCENT LISTED AS PART OF GLASS;
ZEOLITE ( 1%)
Location: VESICLES Replacing: PLAG IN PART
ZEOL FILLS VESICLE IN SLIDE*
Vesicles -
Size(mm): 0.5-2.0
Percent: 40
Location: DISPERSED
Filling: ZEOLITES
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 640/ 670 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 256.50 Rock Type: IGNEOUS
Core: 28 Sample Midpoint(m) : 257.16 Sect/Pc #: 1/PCE 9
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: HYALOPILITIC-INTERSERTAL*
Phenocrysts- CLINOPYROXENE ( 2%)
Size(mm): 0.2-0.5 Morphology: PRISMATIC TO EUHEDRAL
SOME STRAIN SHADOWS,REGULAR AND CASTELATE (SIC)
TWINNING*
Groundmass - GLASS ( 28%)
QUENCH TEXTURE,CPX + PLAG + BROWN GLASS,NO FE-TI
OXIDES;
CLINOPYROXENE ( 20%)
Size(mm): 0.02-0.2 Morphology: PRISMATIC TO SKELETAL
Alteration - CLAY MINERALS ( 7-8%)
Location: LINING Replacing: GLASS
Location: VESICLES
Vesicles -
Size(mm): 0.5-1.0
Percent: 50
Location: DISPERSED
Filling: SOME CLAYS
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 1110/1140 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 256.50 Rock Type: IGNEOUS
Core: 28 Sample Midpoint(m) : 257.63 Sect/Pc #: 1/PCE 14
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL TO VARIOLITIC OR SPHERULITIC*
Phenocrysts- CLINOPYROXENE ( 4%)
Size(mm): 0.5-1.0
SOME PHENOS HAVE IRREGULAR BLOCKY TWINNING,SOME
PHENOS DO NOT GO EXTINCT,MOST ARE RIDDLED WITH
INCLUSION PITS;
ORTHOPYROXENE ( 1%)
Size(mm): 0.5-0.8
RIMMED WITH CPX*
Groundmass - CLINOPYROXENE ( 19%)
Size(mm): 0.1-1 Morphology: BLOCKY TO PRISMATIC
PLAGIOCLASE ( 10%)
Size(mm): 0.1-1 Morphology: SKELETAL
PARTLY ALTERED TO ZEOLITE(?),ALSO INCLUDES GLASS;
GLASS ( 12%)
DEVITRIFIED TO FRESH-PALE BROWN;
MAGNETITE ( 1%)
Alteration - CLAY MINERALS ( 3%)
Location: INTERSTITIAL Replacing: GLASS
ZEOLITE ( 3%)
Location: LINING
Location: VESICLES
Vesicles -
Percent: 50
Leg : 60 Top/Bottom Interval(mm): 1300/1330 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 256.50 Rock Type: IGNEOUS
Core: 28 Sample Midpoint(m) : 257.82 Sect/Pc #: 1/PCE 16
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: QUENCH OR SPHERULITIC*
Phenocrysts- CLINOPYROXENE ( 5%)
Size(mm): 0.2-0.6 Morphology: BLOCKY TO PRISMATIC
INCLUDES SOME OPX RIMMED BY CPX-<1%*
Groundmass - GLASS ( 30%)
BROWN,DEVITRIFIED;
PLAGIOCLASE ( 10%)
Size(mm): 0.1-1.0 Morphology: SKELETAL TO ACICULAR
PLAG IS FIBROUS SPHERULITIC;
CLINOPYROXENE ( 7%)
Size(mm): 0.01-0.2 Morphology: CHUNKY TO PRISMATIC
MAGNETITE ( 2%)
Size(mm): 0.01-0.02
OXIDIZED IN PART*
Alteration - CLAY MINERALS ( 10%)
Location: LINE VESICLES Replacing: GLASS
Location: AND ALONG
Location: FRACTURES
INCIPIENT,RADIAL PHILLIPSITE IN ALTERED ZONE;
HEMATITE ( 2%)
Location: EXTERIOR
Location: SURFACE
Vesicles -
Size(mm): 0.2-0.5
Percent: 45
Location: NEAREST GLASS
Filling: LINED WITH CLAY
Shape: IRREGULAR
SOME ABOUT 1MM,ONE TEAR-DROP SHAPED*
Leg : 60 Top/Bottom Interval(mm): 1420/1460 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 256.50 Rock Type: IGNEOUS
Core: 28 Sample Midpoint(m) : 257.94 Sect/Pc #: 1/PCE 18
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: HYALOPILITIC*
Phenocrysts- CLINOPYROXENE ( 10%)
Size(mm): 0.2-1.0 Morphology: TABULAR TO ANHEDRAL
SOME INTERPENETRATION TWINS;
ORTHOPYROXENE ( 2%)
Size(mm): 0.2-1.0 Morphology: TABULAR
RIMMED BY CPX*
Groundmass - GLASS ( 38%)
CLINOPYROXENE ( 35%)
Size(mm): 0.05-0.3 Morphology: EUHEDRAL TO PRISMATIC
FLOW TEXTURED;
ORTHOPYROXENE ( 3%)
Size(mm): 0.05-0.2 Morphology: EUHEDRAL TO PRISMATIC
PLAGIOCLASE ( 2%)
Alteration - CLAY MINERALS ( 2%)
Location: LINE VESICLES
Vesicles -
Size(mm): 0.2-2.0
Percent: 10
Location: RANDOM
Filling: CLAY.MINS
Shape: ROUND TO
Shape: IRREGULAR
IRREGULAR SHAPE IN VARIOLITES*
Leg : 60 Top/Bottom Interval(mm): 10/ 30 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 266.02 Sect/Pc #: 1/PCE 1
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL TO HYALOPILITIC
THINNER PORTIONS ARE HYALOPILITIC;
Where sampled: NEXT TO GLASSY MARGIN*
Phenocrysts- CLINOPYROXENE ( 4%)
Size(mm): 0.1-1.0 Morphology: EUHEDRAL TO TABULAR
ORTHOPYROXENE ( 1%)
Size(mm): 0.1-1.0 Morphology: TABULAR
Groundmass - CLINOPYROXENE ( 30%)
Size(mm): 0.02-0.1 Morphology: EUHEDRAL-ACICULAR-TABULAR
CHRISTMAS TREE FORMS;
GLASS ( 25%)
CLEAR TO BROWN WITH VAPOR INCLUSIONS(?)*
Alteration - CLAY MINERALS ( 5%)
Location: EXTERIOR Replacing: GLASS
Location: SURFACE AND
Location: LINE VESICLES
ZEOLITE ( 1%)
Location: GROUNDMASS Replacing: GLASS
Vesicles -
Size(mm): 0.5-3.0
Percent: 40
Filling: NONE
Shape: OBLONG TO
Shape: ROUND
Leg : 60 Top/Bottom Interval(mm): 540/ 570 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 266.56 Sect/Pc #: 1/PCE 10
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: VARIOLITIC*
Phenocrysts- CLINOPYROXENE ( 3%)
Size(mm): 0.2-1.0 Morphology: EUHEDRAL TO TABULAR
FAIRLY FRESH*
Groundmass - PLAGIOCLASE ( 35%)
Morphology: SKELETAL TO QUENCH
PARTLY ALTERED;
GLASS ( 15%)
DEVITRIFIED,UP TO 13% ADDITIONAL GLASS ALTERED
TO CLAYS;
CLINOPYROXENE ( 10%)
Morphology: EUHEDRAL TO ANHEDRAL
PARTLY ALTERED;
MAGNETITE ( 4%)
Morphology: ANHEDRAL
Alteration - CLAY MINERALS ( 13%)
Location: THROUGHOUT Replacing: GLASS + LINE VESICLES
POSSIBLY REPLACING OPX(?) + PLAG + OL(?)*
Vesicles -
Size(mm): 0.1-1.0
Percent: 20
Location: THROUGHOUT
Filling: NONE
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 920/ 950 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 266.93 Sect/Pc #: 1/PCE 16
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: VARIOLITIC*
Phenocrysts- CLINOPYROXENE ( 4%)
Size(mm): 0.1-0.5 Morphology: EUHEDRAL TO LATHLIKE
PARTLY ALTERED TO CLAY*
Groundmass - GLASS
IDENTITY OF GLASS TOTALLY UNCERTAIN,OBSERVER
INDICATES NO GLASS IN THIN SECTION-ICD STATES IT
IS THE SAME AS PREVIOUS SECTION 54-57 WHICH HAS
25-28% GLASS;
PLAGIOCLASE ( 20%)
Size(mm): 0.1-0.5 Morphology: SKELETAL,TABULAR,DENDRITIC
PARTLY ALTERED TO CLAYS;
CLINOPYROXENE ( 5%)
Size(mm): 0.1-0.2 Morphology: EUHEDRAL TO SKELETAL
PARTLY ALTERED TO CLAYS;
MAGNETITE ( 2%)
Size(mm): 0.01-0.02 Morphology: SUBHEDRAL
Alteration - CLAY MINERALS ( 25%)
Location: THROUGHOUT Replacing: GLASS + CPX + PLAG + LINES
Replacing: VESICLES
ZEOLITE ( 2%)
Vesicles -
Percent: 40
Leg : 60 Top/Bottom Interval(mm): 380/ 400 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 267.89 Sect/Pc #: 2/PCE 5
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL;
Where sampled: PILLOW INTERIOR
AREA UNCERTAIN*
Phenocrysts- CLINOPYROXENE ( TR%)
Size(mm): 0.5-1.0
Groundmass - GLASS (35-40%)
DEVITRIFIED BY ALTERATION;
CLINOPYROXENE ( 15%)
Size(mm): 0.3-1.0 Morphology: PRISMATIC TO GRANULAR
PLAGIOCLASE ( 10%)
Size(mm): 0.1X1.0 Morphology: SKELETAL TO ELONGATE
CORES OF CPX(?) OR GLASS(?);
PLAGIOCLASE
Size(mm): 0.3X0.3 Morphology: SUBHEDRAL
THE OTHER PLAG XTLS ENCLOSE THESE;
MAGNETITE
Size(mm): 0.01-0.05 Morphology: SKELETAL
Alteration - CLAY MINERALS ( 40%)
Replacing: GLASS
UGLY GREENISH BROWN COLOR*
Vesicles -
Size(mm): 0.1-0.5
Percent: 10
Location: DISPERSED
Filling: CLAY-LINED
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 390/ 420 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 267.91 Sect/Pc #: 2/PCE 6
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL;
Where sampled: PILLOW INTERIOR
AREA UNCERTAIN*
Phenocrysts- CLINOPYROXENE ( <1%)
Size(mm): 0.5-1.0 Morphology: GRANULAR
VERY RARE;
OLIVINE ( 0%)
Groundmass - PLAGIOCLASE ( 20%)
Size(mm): TO 0.5 Morphology: SKELETAL,ELONGATE,DENDRITIC
Morphology: PROJECTIONS
GLASS ( 20%)
TOTALLY ALTERED TO CLAYS;
CLINOPYROXENE ( 15%)
Size(mm): TO 0.1 Morphology: GRANULAR,PRISMATIC
ORTHOPYROXENE ( 5%)
Alteration - CLAY MINERALS ( 20%)
Replacing: GLASS
CLAYS ARE GREEN TO BROWN*
Vesicles -
Size(mm): 0.2-0.5
Percent: 40
Location: DISPERSED
Filling: PARTIAL CLAYS
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 480/ 490 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 266.00 Rock Type: IGNEOUS
Core: 29 Sample Midpoint(m) : 267.99 Sect/Pc #: 2/PCE 6
ROCK = HIGH MG BRONZITE ANDESITE
THIN SECTION IS SMALL;
Texture: INTERSERTAL;
Where sampled: PILLOW INTERIOR - FLOW INTERIOR
AREA UNCERTAIN*
Phenocrysts- CLINOPYROXENE ( TR%)
Groundmass - GLASS ( 30%)
TOTALLY ALTERED TO CLAYS,BROWN-GREEN COLOR;
PLAGIOCLASE ( 25%)
Size(mm): TO 0.5 Morphology: SKELETAL TO ELONGATE
CLINOPYROXENE ( 20%)
Size(mm): 0.05-0.3 Morphology: GRANULAR,PRISMATIC,SKELETAL,
Morphology: DENDRITIC,SOME BLOCKY CHUNKS
ORTHOPYROXENE ( 5%)
MAGNETITE ( TR%)
Size(mm): <0.01 Morphology: SKELETAL
QUARTZ ( TR%)
IDENTITY UNCERTAIN,OPTIC FIGURE CLOSE BUT SOMEWHAT
OFF CENTER*
Alteration - CLAY MINERALS ( 30%)
Location: DISPERSED Replacing: GLASS
Vesicles -
Size(mm): 0.5-1.0
Percent: 20
Location: DISPERSED
Filling: MINOR CLAY
Shape: IRREGULAR
Filling: LINING
Leg : 60 Top/Bottom Interval(mm): 500/ 540 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 275.50 Rock Type: IGNEOUS
Core: 30 Sample Midpoint(m) : 276.02 Sect/Pc #: 1/PCE 8
ROCK = BRONZITE ANDESITE;
Texture: HYALOPILITIC WITH INCIPIENT VARIOLITES*
Phenocrysts- CLINOPYROXENE ( 2%)
Size(mm): 0.2-0.5 Morphology: SKELETAL TO DENDRITIC
ACTUALLY JUST LARGER XTLS IN CONTINUUM;
ORTHOPYROXENE ( TR%)
IDENTITY UNCERTAIN,ENCLOSED WITHIN LARGER CPX
XTLS,NO PARALLEL EXTINCTION*
Groundmass - GLASS ( 53%)
LOCALLY ALTERED TO ZEOLITES;
CLINOPYROXENE ( 40%)
Size(mm): 0.03-0.2 Morphology: SKELETAL,MICROLITIC
SOME COALESCING HETEROGENEOUSLY;
PLAGIOCLASE ( 0%)
OPAQUE MINERALS ( 0%)
Alteration - ZEOLITE ( 10%)
Replacing: GLASS
Vesicles -
Size(mm): 0.15-1.0
Percent: 5
Location: RANDOM
Filling: NONE
SMALL THIN SECTION-ONLY FOUR OR FIVE PRESENT*
Leg : 60 Top/Bottom Interval(mm): 1000/1040 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 275.50 Rock Type: IGNEOUS
Core: 30 Sample Midpoint(m) : 276.52 Sect/Pc #: 1/PCE 16
ROCK = BRONZITE ANDESITE;
Texture: HYALOPILITIC;
Where sampled: GLASSY MARGIN*
Phenocrysts- ORTHOPYROXENE ( <1%)
Size(mm): 0.5-1.0
3 INTERGROWN XTLS,HAS SKELETAL INTERIOR HOLES*
Groundmass - GLASS ( 64%)
MOSTLY ALTERED TO CLAY;
CLINOPYROXENE ( 30%)
Size(mm): 0.1-1.0 Morphology: SKELETAL-ELONGATE MICROLITES
LARGER ONES SHOW FLUIDAL ALIGNMENT*
Alteration - ZEOLITE
Location: CRACK ACROSS
Location: THIN SECTION
GLASS IS BROWN NEXT TO CRACK,ZEOLITES ARE 0.5MM-
2.0CM*
Vesicles -
Size(mm): 1.0-2.0
Percent: 5
Location: RANDOM
Filling: CLAY-LINED THEN
Shape: IRREGULAR-
Filling: FILLED WITH
Shape: FLATTENED
Filling: ZEOLITES
Leg : 60 Top/Bottom Interval(mm): 710/ 730 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 275.50 Rock Type: IGNEOUS
Core: 30 Sample Midpoint(m) : 277.72 Sect/Pc #: 2/PCE 10
ROCK = BRONZITE ANDESITE;
Texture: INTERSERTAL*
Phenocrysts- CLINOPYROXENE ( TR%)
Size(mm): 1.0
Groundmass - PLAGIOCLASE ( 25%)
Size(mm): 0.2-0.5 Morphology: SKELETAL TO DENDRITIC
ELONGATE WITH CENTERED INCLUSIONS;
CLINOPYROXENE ( 13%)
Size(mm): 0.1-0.8 Morphology: GRANULAR,PRISMATIC,SKELETAL
GOES TO MORE SKELETAL AS SIZE DECREASES;
GLASS ( 10%)
ALTERED TO CLAYS;
ORTHOPYROXENE ( 2%)
RARER THAN IN HIGHER BASALTS-CORES 28-29;
MAGNETITE ( TR%)
Size(mm): 0.01-0.05 Morphology: SKELETAL TO SINGLE XTLS
Alteration - CLAY MINERALS ( 5-10%)
Replacing: GLASS
PERVASIVE*
Vesicles -
Size(mm): 0.3-1.0
Percent: 50
Location: THROUGHOUT
Leg : 60 Top/Bottom Interval(mm): 1000/1040 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 275.50 Rock Type: SEDIMENTARY
Core: 30 Sample Midpoint(m) : 278.02 Sect/Pc #: 2/PCE 15
ROCK = LIMESTONE WITH GLASS FRAGMENTS
OBSERVER CALLS THIS A LIMESTONE WITH VESICULAR
ALTERED VOLCANIC (GLASS) FRAGMENTS;
Texture: RECRYSTALLIZED
VERY FINE,NO MICROFOSSILS,SOME MICRITE IN
CAVITIES*
Groundmass - GLASS ( 25%)
TOTALLY ALTERED TO CLAYS;
PLAGIOCLASE ( 15%)
Morphology: SPHERULITIC NEEDLES
CLINOPYROXENE ( 10%)
Morphology: MICROLITES
MAGNETITE ( TR%)
Alteration - CLAY MINERALS ( 25%)
Location: LINE VESICLES Replacing: GLASS
PERVASIVE,CHARTREUSE COLOR*
Vesicles -
Size(mm): 0.1-0.4
Percent: 50
Location: THROUGHOUT
Filling: CLAY-LINED
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 20/ 70 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 285.00 Rock Type: IGNEOUS
Core: 31 Sample Midpoint(m) : 285.05 Sect/Pc #: 1/PCE 1
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC,INTERSERTAL PATCHES;
Where sampled: FLOW INTERIOR*
Groundmass - GLASS ( 30%)
DEVITRIFIED BY ALTERATION TO CLAYS;
PLAGIOCLASE ( 25%)
Size(mm): 0.1-0.5 Morphology: ELONGATE,TWINNED PRISMS
APPROX COMP AN76-60 BY CARLSBAD-ALBITE METHOD,
2VX WITH LARGE V,TWO TYPES OF PLAG-EUHEDRAL
AND ANHEDRAL;
CLINOPYROXENE ( 25%)
Size(mm): 0.1-0.5 Morphology: PRISMATIC-SKELETAL
ORTHOPYROXENE ( 2%)
ILMENITE ( 1%)
Morphology: SKELETAL-GRANULAR
MAGNETITE ( <1%)
Morphology: SKELETAL,EQUANT
HEMATITE ( TR%)
Alteration - CLAY MINERALS ( 15%)
Replacing: GLASS
HEMATITE ( TR%)
Vesicles -
Percent: 10
Leg : 60 Top/Bottom Interval(mm): 1270/1290 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 285.00 Rock Type: IGNEOUS
Core: 31 Sample Midpoint(m) : 286.28 Sect/Pc #: 1/PCE 18
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC,INTERSERTAL
LOCALLY INTERSERTAL NEAR VESICLES;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 35%)
Size(mm): 0.1-0.3 Morphology: EQUANT-TABULAR
TWO TYPES OF INTERSTITIAL PLAG-EUHEDRAL AND
ANHEDRAL;
CLINOPYROXENE ( 23%)
Size(mm): 0.05-0.3 Morphology: GRANULAR-PRISMATIC
GLASS ( 20%)
ALTERED TO CLAYS;
ORTHOPYROXENE ( 2%)
MAGNETITE ( TR%)
Size(mm): 0.01-0.05 Morphology: GRANULAR-SKELETAL
Alteration - CLAY MINERALS ( 20%)
Location: DISPERSED Replacing: GLASS
Vesicles -
Size(mm): 0.2-1.5
Percent: 20
Location: DISPERSED
Filling: NONE
Shape: IRREGULAR-
Shape: ROUND
TWO SIZES-SMALLER(15%) ARE 0.2MM-0.5MM AND ARE
IRREGULAR,LARGER(5%) ARE 1.0MM-1.5MM AND ROUND*
Leg : 60 Top/Bottom Interval(mm): 1300/1310 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 285.00 Rock Type: IGNEOUS
Core: 31 Sample Midpoint(m) : 286.31 Sect/Pc #: 1/PCE 19
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 40%)
Size(mm): 0.1-0.5 Morphology: TABULAR,EUHEDRAL,ANHEDRAL
AS IN PREVIOUS SECTIONS HAS TWO TYPES OF PLAG-
EUHEDRAL AND ANHEDRAL;
CLINOPYROXENE ( 30%)
Size(mm): 0.1-0.5 Morphology: TABULAR,EUHEDRAL
SOME LARGER ONES HAVE INCLUSIONS;
GLASS ( 15%)
TOTALLY ALTERED TO CLAYS;
ORTHOPYROXENE ( 2%)
MAGNETITE ( 1%)
Size(mm): 0.01-0.03 Morphology: EUHEDRAL,CUBIC
Alteration - CLAY MINERALS ( 15%)
Replacing: GLASS
CHARTREUSE COLOR*
Vesicles -
Size(mm): 0.2-1.0
Percent: 12
Location: SCATTERED
Filling: NONE
Shape: IRREGULAR
SMALLER MORE ABUNDANT ON ONE SIDE OF SECTION*
Leg : 60 Top/Bottom Interval(mm): 1300/1350 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 285.00 Rock Type: IGNEOUS
Core: 31 Sample Midpoint(m) : 286.33 Sect/Pc #: 1/PCE 19
ROCK = HIGH MG BRONZITE ANDESITE
SAMPLE TAKEN FROM NEAR A LARGE VESICLE;
Texture: SUBOPHITIC,SPHERULITIC
MATERIAL NEAR LARGE VESICLE MORE SPHERULITIC*
Groundmass - PLAGIOCLASE ( 39%)
Size(mm): 0.1-0.5 Morphology: TABULAR-EUHEDRAL
TWO TYPES OF PLAG IN THREE TO ONE PROPORTIONS OF
EUHEDRAL TO ANHEDRAL;
CLINOPYROXENE ( 34%)
Size(mm): 0.1-0.7 Morphology: EUHEDRAL,TABULAR-SKELETAL
GLASS ( 15%)
ALTERED TO CLAYS;
MAGNETITE ( 1%)
Size(mm): 0.01-0.06 Morphology: EUHEDRAL,CUBIC-BLOCKY
ORTHOPYROXENE ( 1%)
2VZ = 95,ENSTATITE*
Alteration - CLAY MINERALS ( 15%)
Replacing: GLASS
Vesicles -
Percent: 10
Leg : 60 Top/Bottom Interval(mm): 810/ 830 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 294.50 Rock Type: IGNEOUS
Core: 32 Sample Midpoint(m) : 295.32 Sect/Pc #: 1/PCE 6
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC*
Groundmass - PLAGIOCLASE ( 40%)
Size(mm): 0.2-1.0 Morphology: ELONGATE LATHS
LATHS ARE TWINNED LENGTHWISE;
CLINOPYROXENE ( 32%)
Size(mm): 0.2-0.8 Morphology: PRISMATIC,MICROLITIC-SKELETAL
GLASS ( 15%)
CONTAINS NEEDLE-LIKE PLAG SPHERULITES,PARTLY
ALTERED TO CLAYS;
MAGNETITE ( 2%)
Size(mm): 0.01-0.03 Morphology: EQUANT,CUBIC,BLOCKY
ORTHOPYROXENE ( 1%)
Alteration - CLAY MINERALS ( <5%)
Replacing: GLASS
Vesicles -
Size(mm): 0.1-3.0
Percent: 10
Location: SCATTERED
Shape: ROUND TO
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 640/ 660 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 294.50 Rock Type: IGNEOUS
Core: 32 Sample Midpoint(m) : 296.65 Sect/Pc #: 2/PCE 9
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC-INTERSERTAL;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 30%)
Size(mm): 0.1-1.0 Morphology: TABULAR-ACICULAR
PARTLY ALTERED,APPROX COMP AN70-75;
CLINOPYROXENE ( 25%)
Size(mm): 0.1-0.6 Morphology: EQUANT-TABULAR
APPROX COMP UNCERTAIN,PARTLY ALTERED;
GLASS
ALTERED TO CLAYS AND ZEOLITES;
CARBONATE ( 10%)
ON EXTERIOR SURFACE;
MAGNETITE ( 2%)
Size(mm): 0.01-0.1 Morphology: EUHEDRAL-SKELETAL
Alteration - CLAY MINERALS ( 10%)
Location: LINE VESICLES Replacing: GLASS + CPX + PLAG IN PART
CARBONATE ( 10%)
Location: EXTERIOR
Location: SURFACE
ZEOLITE ( 3%)
Location: INTERSTICES Replacing: GLASS
Vesicles -
Size(mm): 0.1-1.0
Percent: 20
Location: THROUGHOUT
Filling: NONE
Shape: IRREGULAR-
Shape: OVOID
MEAN SIZE IS 0.2MM*
Leg : 60 Top/Bottom Interval(mm): 1230/1250 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 294.50 Rock Type: IGNEOUS
Core: 32 Sample Midpoint(m) : 297.24 Sect/Pc #: 2/PCE 15B
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL-SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Phenocrysts- CLINOPYROXENE ( TR%)
MICROPHENOCRYSTS*
Groundmass - GLASS ( 40%)
ALTERED TO CLAYS,ZEOLITES,CARB;
PLAGIOCLASE ( 30%)
Size(mm): 0.1-0.6 Morphology: ACICULAR-TABULAR
APPROX COMP UNCERTAIN,PARTLY ALTERED;
CLINOPYROXENE ( 20%)
Size(mm): 0.1-0.6 Morphology: EQUANT-TABULAR
PARTLY ALTERED;
MAGNETITE ( 2%)
Size(mm): 0.01-0.1
Alteration - CLAY MINERALS ( 10%)
Location: INTERSTITIAL Replacing: GLASS
ZEOLITE ( 3%)
Location: INTERSTITIAL Replacing: GLASS+VESICLES
CARBONATE ( 2%)
Location: INTERSTITIAL Replacing: GLASS
Vesicles -
Size(mm): 0.1-1.0
Percent: 8
Location: THROUGHOUT
Filling: MINOR ZEOLITES
Shape: IRREGULAR-
Shape: OVOID
MEAN SIZE IS 0.2MM*
Leg : 60 Top/Bottom Interval(mm): 1130/1170 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 294.50 Rock Type: IGNEOUS
Core: 32 Sample Midpoint(m) : 298.65 Sect/Pc #: 3/PCE 12B
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 30%)
Size(mm): 0.1-1.0 Morphology: TABULAR,SPHERULITIC,DENDRITIC
MOSTLY TABULAR-ONLY SOME SPHERULITIC + DENDRITIC,
APPROX COMP AN70;
GLASS ( 25%)
MOSTLY ALTERED TO CLAYS;
CLINOPYROXENE ( 10%)
Size(mm): 0.01-1.0 Morphology: EQUANT-TABULAR
PARTLY ALTERED TO CLAY,MEAN = 0.5MM;
MAGNETITE ( 4%)
Alteration - CLAY MINERALS ( 20%)
Location: INTERSTITIAL Replacing: CPX + PLAG + GLASS
ZEOLITE ( 2%)
Location: LINE VESICLES Replacing: UNCERTAIN
CARBONATE ( TR%)
Location: INTERSTITIAL Replacing: GLASS
Vesicles -
Size(mm): 0.1-0.6
Percent: 30
Location: THROUGHOUT
Filling: NONE
Shape: IRREGULAR-
Shape: OVOID
Leg : 60 Top/Bottom Interval(mm): 400/ 420 Describer: Meijer, A.
Hole: 458 Top of Core Depth(m) : 294.50 Rock Type: IGNEOUS
Core: 32 Sample Midpoint(m) : 299.41 Sect/Pc #: 4/PCE 4B
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL-SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Groundmass - GLASS ( 30%)
DEVITRIFIED MOSTLY,ALTERED TO CLAYS AND ZEOLITES;
PLAGIOCLASE ( 25%)
Size(mm): 0.1-1.0 Morphology: ACICULAR-TABULAR
APPROX COMP AN70,PARTLY ALTERED TO CLAY;
CLINOPYROXENE ( 25%)
Size(mm): 0.1-0.6 Morphology: EQUANT-TABULAR
APPROX COMP UNCERTAIN,PARTLY ALTERED TO CLAY;
MAGNETITE
Morphology: EQUANT-ANHEDRAL
Alteration - CLAY MINERALS ( 20%)
Location: INTERSTICES Replacing: GLASS + CPX + PLAG
ZEOLITE ( 2%)
Location: INTERSTICES Replacing: GLASS
Vesicles -
Size(mm): 0.1-1.0
Percent: 15
Location: THROUGHOUT
Filling: MINOR ZEOLITES
Shape: IRREGULAR-
Shape: OVOID
Leg : 60 Top/Bottom Interval(mm): 580/ 600 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 304.00 Rock Type: IGNEOUS
Core: 33 Sample Midpoint(m) : 304.59 Sect/Pc #: 1/PCE 8
ROCK = HIGH MG BRONZITE ANDESITE
COARSE GRAINED;
Texture: SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 60%)
Size(mm): 0.1-1.0 Morphology: EUHEDRAL-MICROLITIC-PATCHY
PLAG IS OF TWO TYPES-40% IS EUHEDRAL-TABULAR-
MICROLITIC-IDIOMORPHIC AND 60% IS PATCHY-
INTERSTITIAL-XENOMORPHIC,ABUNDANT;
CLINOPYROXENE ( 22%)
Size(mm): 0.1-0.5 Morphology: GRANULAR-PRISMATIC
MICROCRYST GROUNDMASS ( 5%)
QUARTZ ( 2%)
Size(mm): 0.1-0.2 Morphology: ANHEDRAL
Alteration - CLAY MINERALS ( 3%)
IN MESOSTASIS*
Vesicles -
Size(mm): 0.1-0.8
Percent: 10
Location: SCATTERED
Filling: NONE
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 700/ 720 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 304.00 Rock Type: IGNEOUS
Core: 33 Sample Midpoint(m) : 306.21 Sect/Pc #: 2/PCE 8B
ROCK = HIGH MG BRONZITE ANDESITE
COARSEST GRAINED ROCK AT SITE 458;
Texture: SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 40%)
Morphology: TABULAR-MICROLITE,PATCHY
TWO TYPES OF PLAG-TABULAR TO MICROLITE AND PATCHY
INTERSTITIAL;
CLINOPYROXENE ( 34%)
MICROCRYST GROUNDMASS ( 15%)
ALTERED TO BROWN AND GREEN CLAYS AND FE.OXIDES;
MAGNETITE ( 1%)
Morphology: CUBIC,SKELETAL
ORTHOPYROXENE ( TR%)
ALTERATION TO CLAYS*
Alteration - CARBONATE ( 10%)
ALL IN ONE VEIN ABOUT 0.5CM WIDE;
CLAY MINERALS ( 5%)
IN MESOSTASIS*
Vesicles -
Size(mm): 0.1-1.0
Percent: 10
Location: SCATTERED
Filling: NONE
Shape: IRREGULAR
INTERSERTAL BROWN PATCHES NEAR LARGER VESICLES*
Leg : 60 Top/Bottom Interval(mm): 480/ 520 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 313.50 Rock Type: IGNEOUS
Core: 34 Sample Midpoint(m) : 315.50 Sect/Pc #: 2/PCE 2A
ROCK = HIGH MG BRONZITE ANDESITE
FAIRLY COARSE GRAINED;
Texture: SUBOPHITIC;
Groundmass - PLAGIOCLASE ( 40%)
Morphology: EUHEDRAL,MICROLITIC,PATCHY
TWO TYPES OF PLAG-MICROLITIC AND INTERSTITIAL,
APPROX COMP AN45,2VZ OF 85;
CLINOPYROXENE ( 23%)
Morphology: EUHEDRAL,PRISMATIC-SKELETAL
MICROCRYST GROUNDMASS ( 10%)
CLAYS;
MAGNETITE ( 1%)
Morphology: CUBIC-SKELETAL
QUARTZ ( 1%)
IDENTITY UNCERTAIN,STRAINED*
Alteration - CLAY MINERALS ( 10%)
ZEOLITE ( TR%)
Location: INTERSTITIAL Replacing: GLASS
CARBONATE ( TR%)
Location: FILL VESICLES
Vesicles -
Percent: 20
Leg : 60 Top/Bottom Interval(mm): 80/ 100 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 323.00 Rock Type: IGNEOUS
Core: 35 Sample Midpoint(m) : 323.09 Sect/Pc #: 1/PCE 2
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: SUBOPHITIC;
Where sampled: FLOW INTERIOR*
Groundmass - PLAGIOCLASE ( 30%)
Size(mm): 0.1-0.7 Morphology: MICROLITIC
PATCHY INTERSTITIAL MATERIAL AS WELL,SOME LOW 2VZ
POSSIBLY K-OLIGOCLASE(?);
GLASS ( 28%)
ALTERED AFTER INTERSERTAL GLASS,MESOSTASIS;
CLINOPYROXENE ( 20%)
Size(mm): 0.1-0.7
QUARTZ ( TR%)
IDENTITY UNCERTAIN,MOSTLY STRAINED*
Alteration - CLAY MINERALS ( 15%)
Replacing: INTERSERTAL GLASS
CARBONATE ( 2%)
Location: IN ONE VEIN
Vesicles -
Size(mm): 0.1-1.0
Percent: 20
Location: SCATTERED
Filling: NONE
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 690/ 710 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 323.00 Rock Type: IGNEOUS
Core: 35 Sample Midpoint(m) : 325.20 Sect/Pc #: 2/PCE 8
ROCK = HIGH MG BRONZITE ANDESITE
ALTERED GLASSY CPX-RICH,OF ALL OF THIS TYPE OF
ROCK IN CORES 28-40 THIS IS THE GLASSIEST,CLOSEST
TO PILLOW MARGIN;
Texture: SPHERULITIC;
Where sampled: GLASSY MARGIN*
Groundmass - GLASS ( 85%)
FAINTLY BIREFRINGENT NEEDLES DISPERSED IN GLASS-
POSSIBLY PLAG(?) OR CLAYS(?);
CLINOPYROXENE ( 10%)
Morphology: MICROLITIC,SPHERULITIC
MOST ARE SPHERULITIC,CPX ABUNDANT SHEAF
SPHERULITES*
Alteration - CLAY MINERALS
Replacing: CPX + GLASS
Vesicles -
Size(mm): 0.05-0.1
Percent: 5
Location: SCATTERED
Filling: NONE
Shape: ROUND
Leg : 60 Top/Bottom Interval(mm): 450/ 470 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 342.00 Rock Type: IGNEOUS
Core: 37 Sample Midpoint(m) : 342.46 Sect/Pc #: 1/PCE 5
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL-SPHERULITIC;
Where sampled: PILLOW INTERIOR-FLOW INTERIOR;
AREA UNCERTAIN,ROCK IS IN TWO ZONES*
Groundmass - MICROCRYST GROUNDMASS ( 50%)
MESOSTASIS IS BROWN GLASS WITH ABUNDANT TINY XTLS
OF PLAG + CPX,NOW LARGELY ALTERED TO CLAYS;
PLAGIOCLASE ( 30%)
Morphology: MICROLITIC
CLINOPYROXENE ( 14%)
Morphology: IRREGULAR,SKELETAL
ORTHOPYROXENE ( 1%)
MAGNETITE ( TR%)
Alteration - CLAY MINERALS ( 25%)
Replacing: MESOSTASIS
Vesicles -
Size(mm): 0.1-1.0
Percent: 5
Location: SCATTERED
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 50/ 70 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 351.50 Rock Type: IGNEOUS
Core: 38 Sample Midpoint(m) : 351.56 Sect/Pc #: 1/PCE 1A
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: HYALOPILITIC,SOMEWHAT PILOTAXITIC;
Where sampled: GLASSY MARGIN*
Phenocrysts- CLINOPYROXENE ( 5%)
Size(mm): 0.2-0.7 Morphology: SKELETAL,DENDRITIC,PRISMATIC
ORTHOPYROXENE ( 1%)
Size(mm): 0.3-0.5 Morphology: PRISMATIC
2VX OF 80-85,BRONZITE*
Groundmass - GLASS ( 54%)
ONCE ALL GLASS-NOW ALTERED,GLASSY FRAGMENT WITH
INTENSE ZONED ALTERATION TO ZEOLITE + CLAYS +
FE-OXIDES ON RIMS,CLEAR ZEOLITE ALONE IN MIDDLE;
CLINOPYROXENE ( 35%)
Size(mm): 0.01-0.1 Morphology: MICROLITES
CPX NOT AFFECTED BY GLASS ALTERATION*
Alteration - CLAY MINERALS
Replacing: GLASS
ZEOLITE
Replacing: GLASS
PROPORTIONS VARY FROM PLACE TO PLACE OF ZEOLITES
AND CLAYS*
Vesicles -
Size(mm): 0.5-1.0
Percent: 5
Location: ON ONE SIDE
Filling: CLAYS + ZEOLITE
Shape: ROUND
Leg : 60 Top/Bottom Interval(mm): 330/ 350 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 370.50 Rock Type: IGNEOUS
Core: 40 Sample Midpoint(m) : 370.84 Sect/Pc #: 1/PCE 1D
ROCK = HIGH MG BRONZITE ANDESITE
ALTERED;
Texture: HYALOPILITIC;
Where sampled: GLASSY MARGIN*
Phenocrysts- CLINOPYROXENE ( 3%)
Size(mm): 0.2-0.5 Morphology: SKELETAL-PRISMATIC
ALTERED*
Groundmass - GLASS ( 47%)
ONCE GLASS BUT NOW CLAYS AND HAS A STREAKY
APPEARANCE OF FLOW PRODUCED LINES OF CLEAR CPX-
FREE GLASS NOW ALTERED TO CLAYS;
CLINOPYROXENE ( 10%)
Size(mm): 0.1-0.3 Morphology: SKELETAL,MICROLITIC
TINY SKELETAL MICROLITES*
Alteration - CLAY MINERALS ( 60%)
Replacing: CPX+GLASS+LINE VESICLES
Vesicles -
Size(mm): 0.1-0.5
Percent: 40
Leg : 60 Top/Bottom Interval(mm): 880/ 900 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 370.50 Rock Type: IGNEOUS
Core: 40 Sample Midpoint(m) : 372.89 Sect/Pc #: 2/PCE 7
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL
ALTERED,SOME SPHERULITIC ASPECTS;
Where sampled: PILLOW INTERIOR*
Phenocrysts- CLINOPYROXENE ( 5%)
Size(mm): 0.2-0.7 Morphology: SKELETAL
ALTERED MOSTLY TO CLAYS*
Groundmass - CLINOPYROXENE ( 5%)
Size(mm): 0.1-0.2
ABUNDANT INTERSTITIAL CPX MICROLITES ARRANGED IN
SPHERULITIC SWORLS AND NEEDLES,MANY ARE SKELETAL
AND ALTERED TO CLAYS;
PLAGIOCLASE
AMOUNT HARD TO ESTIMATE*
Alteration - CLAY MINERALS ( 50%)
Location: MOST PLACES Replacing: MOST OF THE ROCK
Vesicles -
Size(mm): 0.1-1.0
Percent: 40
Location: SCATTERED
Filling: CLAY-LINED
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 30/ 50 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 380.00 Rock Type: IGNEOUS
Core: 41 Sample Midpoint(m) : 380.04 Sect/Pc #: 1/PCE 1
ROCK = APHYRIC BASALT;
Texture: INTERSERTAL;
Where sampled: FLOW INTERIOR;
AREA UNCERTAIN*
Phenocrysts- PLAGIOCLASE ( TR%)
Size(mm): 0.5-1.0
APPROX COMP UNCERTAIN,NONE ORIENTED FOR COMP.;
CLINOPYROXENE ( TR%)
APPROX COMP UNCERTAIN*
Groundmass - GLASS ( 52%)
DIVIDED BETWEEN BROWN OXIDIZED GLASS AND PALE
GREEN CLAYS,BROWN MOST ABUNDANT NEAR
INTERCONNECTED VESICLES;
PLAGIOCLASE ( 25%)
Morphology: MICROLITIC
CLINOPYROXENE ( 5%)
Morphology: MICROLITIC-SKELETAL
CPX ABUNDANCE LOW AS A RESULT OF REPLACEMENT BY
CLAYS AND OPAQUES;
MAGNETITE ( 3%)
Morphology: CUBIC,SKELETAL
Alteration - CLAY MINERALS ( 25%)
Location: SCATTERED Replacing: CPX+GLASS+LINE VESICLES
Vesicles -
Size(mm): 0.1-5.0
Percent: 15
Location: SCATTERED
Filling: MOST EMPTY
Shape: ROUND TO
Shape: ELONGATE
STRUNG OUT IN LINES,SOME INTERCONNECTED*
Leg : 60 Top/Bottom Interval(mm): 220/ 260 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 380.00 Rock Type: IGNEOUS
Core: 41 Sample Midpoint(m) : 380.24 Sect/Pc #: 1/PCE 1
ROCK = APHYRIC BASALT;
Texture: INTERSERTAL;
Where sampled: PILLOW INTERIOR*
Phenocrysts- PLAGIOCLASE ( TR%)
Size(mm): 1.0 Morphology: EUHEDRAL
ONE RIDDLED WITH HOLES,APPROX COMP UNCERTAIN;
CLINOPYROXENE ( TR%)
Groundmass - MICROCRYST GROUNDMASS ( 55%)
MOSTLY GLASS ALTERED TO CLAYS,DARKER MORE
SPHERULITIC ZONES NEAR VESICLES;
PLAGIOCLASE ( 25%)
Morphology: TABULAR,MICROLITIC,SKELETAL,
Morphology: IRREGULAR
MOSTLY MICROLITIC;
CLINOPYROXENE ( 4%)
MAGNETITE ( 1%)
Alteration - CLAY MINERALS ( >50%)
Location: MOST PLACES Replacing: GLASS
MOST IS CLEAR,SOME PALE BROWN OR PALE GREEN*
Vesicles -
Size(mm): 0.1-1.0
Percent: 15
Location: SCATTERED
Filling: NONE
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 340/ 370 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 399.00 Rock Type: IGNEOUS
Core: 43 Sample Midpoint(m) : 399.36 Sect/Pc #: 1/PCE 6
ROCK = HIGH MG BRONZITE ANDESITE
VERY BADLY ALTERED AND THEREFORE CANNOT DO MUCH
QUANTITATIVELY;
Texture: SPHERULITIC;
Where sampled: NEXT TO GLASSY MARGIN*
Groundmass - PLAGIOCLASE
ABUNDANT SWORLS OF SPHERULITIC PLAG;
CLINOPYROXENE
MINOR SKELETAL CPX,CRYSTALLIZED BEFORE PLAG,PLAG
AND CPX RELATIVE ABUNDANCIES QUITE DIFFERENT FROM
CORE 41 THIN SECTIONS;
GLASS
GLASS IN BETWEEN SPHERULITE FIBERS NOW ALTERED TO
CLAYS,CLAYS ARE UBIQUITOUS*
Alteration - CLAY MINERALS
Replacing: GLASS
Vesicles -
Size(mm): 0.1-1.0
Percent: 10
Location: SCATTERED
Filling: CLAYS
Shape: ROUND TO
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 1040/1070 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 399.00 Rock Type: IGNEOUS
Core: 43 Sample Midpoint(m) : 400.06 Sect/Pc #: 1/PCE 19
ROCK = HIGH MG BRONZITE ANDESITE;
Texture: INTERSERTAL,APHYRIC,SPHERULITIC
SPHERULITIC NEAR VESICLES;
Where sampled: PILLOW INTERIOR
AREA UNCERTAIN*
Groundmass - PLAGIOCLASE ( 50%)
Size(mm): 0.2-0.5 Morphology: SKELETAL-EUHEDRAL,ANHEDRAL
TWO TYPES-INTERSTITIAL TYPE IS ANHEDRAL WITH
APPROX COMP OF AN45,SKELETAL-EUHEDRAL TYPE HAS
APPROX COMP OF AN50-55;
MICROCRYST GROUNDMASS ( 37%)
ALTERED TO CLAYS + FE-OXIDES,BROWNISH COLOR;
CLINOPYROXENE ( 5%)
Size(mm): <0.2
MORPHOLOGY DIFFICULT TO RESOLVE BECAUSE OF
COMPOSITION;
MAGNETITE ( 1%)
Morphology: CUBIC
Alteration - CLAY MINERALS
Replacing: GLASS + VESICLES
Vesicles -
Size(mm): 0.1-1.5
Percent: 7
Location: SCATTERED
Filling: SOME WITH
Shape: ROUND TO
Filling: YELLOW CLAYS
Shape: IRREGULAR
Leg : 60 Top/Bottom Interval(mm): 780/ 800 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 427.50 Rock Type: IGNEOUS
Core: 46 Sample Midpoint(m) : 428.29 Sect/Pc #: 1/PCE 7
ROCK = APHYRIC BASALT
THIN SECTION IS POOR;
Texture: PILOTAXITIC;
Where sampled: NEXT TO GLASSY MARGIN*
Phenocrysts- PLAGIOCLASE ( TR%)
Size(mm): 0.1-0.2 Morphology: EUHEDRAL
MICROPHENOCRYSTS*
Groundmass - GLASS ( 89%)
LITTLE RED ALTERATION ZONES PARALLELING DIRECTION
OF PLAG ALIGNMENT-PROBABLY ARE PARTINGS AND
VESICLE STRINGS IN THE ROCK,MICROXLN ONCE GLASS
NOW ALTERED TO CLAYS + RED FE-OXIDES (SKELETAL);
PLAGIOCLASE ( 10%)
APPROX COMP AN54(?),MAX. EXTINCTION,FLUIDAL
ALIGNMENT;
CLINOPYROXENE ( TR%)
Morphology: SKELETAL
PROBABLY NEEDLE-LIKE SPHERULITES*
Alteration - CLAY MINERALS
Location: MOST PLACES Replacing: GLASS
PERCENT MEANINGLESS-TOO DISPERSED WITH FE-OX ETC.*
Vesicles -
Size(mm): 0.2-0.5
Percent: 1
Location: SCATTERED
Filling: CLAY-LINED
Shape: ROUND
ONLY A FEW PRESENT*
Leg : 60 Top/Bottom Interval(mm): 690/ 710 Describer: Natland, J.
Hole: 458 Top of Core Depth(m) : 446.50 Rock Type: IGNEOUS
Core: 48 Sample Midpoint(m) : 447.20 Sect/Pc #: 1/PCE 1
ROCK = APHYRIC BASALT;
Texture: PILOTAXITIC;
Where sampled: NEXT TO GLASSY MARGIN*
Phenocrysts- PLAGIOCLASE ( TR%)
Morphology: EUHEDRAL
APPROX COMP AN72 BY A-NORMAL METHOD;
CLINOPYROXENE ( TR%)
Morphology: GRANULAR
Groundmass - GLASS ( 84%)
MESOSTASIS OF HIGHLY ALTERED DEVITRIFIED GLASS
WHOSE
COLOR IS NOW MURKY BROWN,IT IS NOT TRANSLUCENT;
PLAGIOCLASE ( 10%)
Size(mm): 0.02-0.07 Morphology: MICROLITIC
CLINOPYROXENE ( 6%)
Morphology: MICROLITIC,SKELETAL
MAGNETITE ( TR%)
Alteration - CLAY MINERALS
Location: DISPERSED Replacing: GLASS
MODERATELY ABUNDANT;
FERROUS OXIDE
Location: DISPERSED Replacing: GLASS
RED COLOR,ABUNDANT*
Vesicles -
Size(mm): 0.1-1.0
Percent: 3-4
Location: SCATTERED
Filling: CLAY-LINED
Shape: ROUND
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