Leg : 7 Top/Bottom Interval(mm): 0/ 0 Describer: DSDP microfilm
Hole: 65 Top of Core Depth(m) : 145.00 Rock Type: SEDIMENTARY
Core: 17 Sample Midpoint(m) : 145.10 Sect/Pc #: CC/
ROCK = VOLCANIC SANDSTONE
FRAGMENTS OF CHERT ARE COMMONLY IN CONTACT WITH
MUDSTONES AND COARSE SANDSTONES;
Texture: COARSE-GRAINED*
CONTAINS GRAINS UP TO 3MM DIAMETER.GRAINS BETWEEN
APPROX 0.7 AND 2MM ARE MOST ABUNDANT.THEY ARE
FRAGMENTS OF ALTERED VOLCANIC ROCK,AS WELL AS
LESSER AMOUNTS OF FORAMS,FISH REMAINS,AND
MUDSTONES,ALL SET IN AN OPALINE(LOCALLY
CHALCEDONIC OR CALCAREOUS)GROUNDMASS.TO SHOW
SOMETHING OF THE GREAT DIVERSITY OF LITHOLOGIC
TYPES PRESENT AS SAND GRAINS,THE FOLLOWING LIST IS
OF GRAINS INTERCEPTED ON A TRAVERSE ACROSS THIS
THIN SECTION: FINELY LAMINATED PRE-EXISTING TUFF,
PALAGONITE,SILICIFIED LITHIC TUFF,ALTERED VOLCANIC
(HEMATITE,CLAY,CHLORITE,MAGNETITE?),LITHIC GRAIN-
NOW ZEOLITE, PARTLY DEVITRIFIED GLASS,PALAGONITE,
FRAGMENT OF BANDED CHERT(CHALCEDONY IN COLLOFORM
LAYERS LESS THAN .01MM THICK),LITHIC GRAIN-NOW
ZEOLITE AND CHALCEDONY,GLASS PARTLY DEVITRIFIED TO
MOSAIC OPAL AND CLAY,ALTERED VOLCANIC(BASTITE
SERPENTINE AND CLAY),FORAM WITH PRISMATIC CALCITE
WALLS("PSEUDOISOGYRE"),VOLCANIC GRAIN WITH PLAG
TWIN ONLY PARTLY ALTERED TO CLAY,VERY FINE GRAINED
CHALCEDONY AROUND IRREGULAR TO ROUNDED CLAY MASSES
(PROBABLY ORIGINALLY VESICULAR GLASS),ALTERED
VOLCANIC(BASTITE SERPENTINE,CLAY AND IDDINGSITE),
SILICIFIED MUDSTONE,SILICIFIED VOLCANIC WITH
RADIAL CHALCEDONY IN VESICLE,FORAM WITH PRISMATIC
CALCITE WALL,LARGE AGGREGATE GRAIN OF EARLIER
SILICIFIED VOLCANIC AND PALAGONITE GRAINS,EACH
RIMMED BY COLLOFORM CHALCEDONY THAT CEMENTS THEM
TO EACH OTHER-BOTH CEMENT AND GRAINS NOW FRACTURED
LIKE IN MINIATURE A "POLYMICTIC CONGLOMERATIC
QUARTZITE",SILICIFIED AND CLAYEY VOLCANIC GLASS,
PALAGONITE,ETC. ALSO SEEN,BUT NOT ON THIS RANDOM
TRAVERSE,WERE SUCH GRAINS AS: COLLOFORM PALAGONITE
AROUND VESICLES,PALAGONITE GRAINS WITHIN
SILICIFIED MUDSTONE GRAINS,FORAMS WITH WALLS OF
MOSAIC CALCITE,FORAMS WITH CHAMBERS CONTAINING
MICRITE,MICRITE GRAINS,ALTERED ROUNDED FELDSPAR
WITH CLAY BLADES PARALLEL TO ORIGINAL CLEAVAGE,
MUDSTONE WITH RADIOLARIAN SKELETONS SHOWING
SMALL SCALE(ABOUT .3MM)RIPPLES,LARGELY ALTERED TO
CHALCEDONY,POIKILITIC CALCITE XTLS WITH ALTERED
GLASS? AND CHALCEDONY INCLUSIONS.THIS BED IS
COMPOSED OF A VARIETY OF PRE-EXISTING PYROCLASTIC
AND ORGANIC ROCKS.PROBABLY MOST OF THE ALTERATION
OF THE VOLCANIC ROCKS TOOK PLACE BEFORE THEY WERE
ERODED AND REDEPOSITED AS THIS BED*
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