Leg : 21 Top/Bottom Interval(mm): 0/ 50 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 357.05
Core: 34 Top of Core Depth (m) : 357.00
Sect: 1 Top of Section Depth(m): 357.00
LITHOLOGY: MUDSTONE;
Leg : 21 Top/Bottom Interval(mm): 50/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 358.50
Core: 34 Top of Core Depth (m) : 357.00
Sect: 1 Top of Section Depth(m): 357.05
LITHOLOGY: RHYOLITE TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : INTERVAL (5-29) IS GREENISH BLACK 5GY2/1 RHYOLITE
TUFF WITH ABUNDANT XTLN IRON SULPHIDES (PYRITE?) IN
LAYERS, CLEAR QTZ, CHLORITE, AND GREEN MINERALS IN
VERY FINE-GRAINED GLASS(?) MATRIX, QTZ UP TO 20%,
INTERVAL (29-37) IS DARK GREENISH GRAY (WET) TO
GREENISH BLACK 5Y2/1 (WET) RHYOLITE TUFF (POSSIBLY
IGNIMBRITE), 2% BIPYRAMIDAL CLEAR QTZ PHENOS IN A
VERY FINE-GRAINED MATRIX, COLOR BANDING OF MATRIX
INCLINED 40 DEGREES TO PERPENDICULAR OF CORE, GREEN
VEINLETS CUT MATRIX AND RIM PHENOS, MATRIX PROBABLY
GLASS, INTERVAL (37-93) IS DARK GREENISH GRAY
5GY4/1 (WET) RHYOLITE TUFF (POSSIBLY IGNIMBRITE)
40 DEGREES DIP OF LIGHT GREENISH GRAY 5GY8/1 AND
GREENISH GRAY 5GY6/1 MATRIX, FIRST APPEARANCE OF
VOLCANIC ROCK FRAGMENTS (LIGHT BROWNISH GRAY 5YR6/1)
VERY FINE-GRAINED GLASSY(?) UP TO 5MM ACROSS BUT
<2%-5% TOTAL ROCK QTZ PHENOS, MATRIX IS APHANITIC
GLASS? ROCK FRAGMENTS ARE ALL LAPILLI SIZE WITH 1CM
MAXIMUM SIZE, AT 87CM DIP OF COLOR BANDING IN GLASSY
MATRIX IS ABOUT 60 DEGREES, INTERVAL (93-150) IS
OLIVE BLACK 5Y2/1 WITH BANDS OF GREENISH GRAY 5GY6/1
AND DIP ABOUT 60 DEGREES, UNDER BINOCULAR SCOPE
BROWNISH GRAY 5GY8/1 GLASS, LITHIC VOLCANIC
FRAGMENTS OF SIMILAR TEXTURE (GLASSY) TO 2CM
ACROSS BUT MOSTLY 5MM, LITTLE FRAGMENTS UP TO 30%
OF ROCK, GLASSY MATRIX HAS CONCHOIDAL FRACTURE AND
PERLITIC TEXTURE, RHYOLITE VITRIC LAPILLI TUFF-
POSSIBLY A RHYOLITE WELDED TUFF OR IGNIMBRITE;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 360.00
Core: 34 Top of Core Depth (m) : 357.00
Sect: 2 Top of Section Depth(m): 358.50
LITHOLOGY: RHYOLITE VITRIC LAPILLI TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : BROWNISH BLACK 5YR2/1 (WET) TO OLIVE BLACK AND DARK
GREENISH GRAY 5GY4/J1 ON DRY SUFRACES, GLASSY
RHYOLITIC FRAGMENTS LAPILLI SIZE (2-20MM) IN A
QUARTZ PHENO BEARING (2-5% QTZ) GLASSY GNDMASS,
PERLITIC TEXTURE AND CONCHOIDAL FRACTURE ARE
PROMINENT FEATURES, VITRIC FRAGMENTS ARE SUBANGULAR
AND COMPRISE 25% OF ROCK BUT IN MANY PLACES ARE
SIMILAR IN COMPOSITION TO GNDMASS, FLOW BANDING(?)
OF GLASS AROUND FRAGMENTS IS DIFFICULT TO ESTIMATE,
THIS SECTION IS IN SHARP CONTRAST TO SECTION 39-1
WHERE VOLCANIC RICH FRAGMENTS ARE EASILY
DISTINGUISHABLE FROM GLASSY MATRIX, LAYERING IN THIS
SECTION IS NOT OBVIOUS EXCEPT AT 80CM;
Leg : 21 Top/Bottom Interval(mm): 610/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 367.50
Core: 35 Top of Core Depth (m) : 366.00
Sect: 1 Top of Section Depth(m): 366.61
LITHOLOGY: RHYOLITE VITRIC LAPILLI TUFF;
SIMILAR TO SECTION 34-2;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : RHYOLITE GLASS WITH CLEAR QTZ PHENOS IN A GLASSY
GNDMASS THAT HAS A PERLITIC TEXTURE AND CONCHOIDAL
FRACTURE, IN PLACES VERY FINELY XTLN IRON SULPHIDES
(PYRITE) REPLACE ROCK, GREEN COLORED GLASSY GNDMASS
AND TINY VEINLETS INDICATE ALTERATION PROBABLY
INVOLVING CHLORITE MINERALS, SLABBED SECTION AT 74CM
SUGGESTS FAINT LAYERING DIPPING 60 DEGREES;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 369.00
Core: 35 Top of Core Depth (m) : 366.00
Sect: 2 Top of Section Depth(m): 367.50
LITHOLOGY: RHYOLITE VITRIC LAPILLI TUFF;
SIMILAR TO SECTIONS 35-1 AND 34-2;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : NO CHANGE IN COLOR, BASICALLY OLIVE BLACK 5Y2/1 OR
BROWNISH BLACK 5YR2/1 WHEN WET AND OLIVE GRAY 5Y4/1
TO GREENISH GRAY 5GY6/1 WHEN DRY, MANY OF THE VITRIC
CLASTS ARE GREENISH GRAY 5GY6/1 TO DARK GREENISH
GRAY 5GY4/1 VERSUS BROWNISH GRAY 5YK4/1 FOR THE
GNDMASS WHEN WET AND UNDER INTENSE MICROSCOPE LAMP,
PARTS OF THE SECTION SUCH AS 110-117CM ARE NEARLY
ALL GRAYISH BLACK GLASS WITH PERLITIC TEXTURE, NOT
MUCH CLASTS, ALMOST PITCHSTONE, AT TOP GLASS HAS
R.I.<1.500 WHICH IS ABOUT 70% SILICA, CONFIRMING
RHYOLITE COMPOSITION;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 370.50
Core: 35 Top of Core Depth (m) : 366.00
Sect: 3 Top of Section Depth(m): 369.00
LITHOLOGY: RHYOLITE VITRIC LAPILLI TUFF;
VERY SIMILAR TO 35-2;
Comments : FROM 0-47CM THERE ARE ABUNDANT 10% CLEAR FELDSPAR
PHENOS (POSSIBLY SANADINE) BESIDES BIPYRAMIDAL
QTZ (<10%), GLASS FRAGMENTS ARE ONLY 10-20% OF ROCK
AND GNDMASS IS BANDED BROWNISH GRAY 5YR4/, BLACK
AND GREENISH GRAY GLASS WITH PERLITIC TEXTURE AND
CONCHOIDAL FRACTURE, CARLSBAD TWINS ON FELDSPARS ,
INTERVAL (47-150) IS MORE LIKE THE BULK OF 35-2 WITH
PLAINLY VISABLE VITRIC FRAGMENTS AND NO LARGE
FELDSPAR XTLS, THIS INTIRE SECTION HAS LAMINAE
STRUCTURE OF DIFFERENT COLORED GLASS GNDMASS DIPPING
90-60 DEGREES;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 370.60
Core: 35 Top of Core Depth (m) : 366.00
Sect: CC Top of Section Depth(m): 370.60
LITHOLOGY: FRAGMENTED VITROPHYRIC RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : FRAGMENTS ARE BROWNISH GRAY, GREENISH GRAY, AND
BLACK, PERLITIC GLASSY GNDMASS WITH QTZ PHENOS,
POSSIBLY TUFF;
Leg : 21 Top/Bottom Interval(mm): 1000/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 376.50
Core: 36 Top of Core Depth (m) : 375.00
Sect: 1 Top of Section Depth(m): 376.00
LITHOLOGY: RHYOLITE VITRIC LAPILLI TUFF;
SAME AS 35-3;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : HAS SEVERAL PERCENT CLEAR FELDSPAR (SANADINE?), NO
SIGN OF BANDING;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 376.60
Core: 36 Top of Core Depth (m) : 375.00
Sect: CC Top of Section Depth(m): 376.60
LITHOLOGY: VITROPHYRIC RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : BROWNISH GRAY (5YR4/1), GLASS HAS PERLITIC TEXTURE,
PYRITE LINES PERLITIC CRACKS;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 384.10
Core: 37 Top of Core Depth (m) : 384.00
Sect: CC Top of Section Depth(m): 384.10
LITHOLOGY: FRAGMENTED VITROPHYRIC RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : FRAGMENTS SHOW FLUIDAL BANDING;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 393.10
Core: 38 Top of Core Depth (m) : 393.00
Sect: CC Top of Section Depth(m): 393.10
LITHOLOGY: FRAGMENTED VITROPHYRIC RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : BLACK BROWNISH GRAY AND GREENISH GRAY FRAGMENTS;
Leg : 21 Top/Bottom Interval(mm): 850/1170 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 403.17
Core: 39 Top of Core Depth (m) : 402.00
Sect: 1 Top of Section Depth(m): 402.85
LITHOLOGY: RHYOLITE PUMICE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : DARK YELLOWISH BROWN 10YR4/2 WITH BLACK GLASS FILLED
POCKETS UP TO 3CM ACROSS, BIPYRAMIDAL QTZ IN PUMICE,
ALSO RARE FRAGMENTS OF LIGHT GREENISH GRAY APHANITIC
VITRIC RHYOLITE?
Leg : 21 Top/Bottom Interval(mm): 1070/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 403.50
Core: 39 Top of Core Depth (m) : 402.00
Sect: 1 Top of Section Depth(m): 403.07
LITHOLOGY: RHYOLITE VITRIC (PUMICE) LAPILLIC TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED, INTERVALS (107-115) AND
(120-150);
Comments : DARK GREENISH GRAY 5GY4/1, COMPOSED MAINLY OF PUMICE
FRAGMENTS AVERAGING 5-7MM ACROSS, 15% OF BLACK
OBSIDIAN AND OLIVE BLACK LAMINATED GLASS WITH
OCCASIONAL QTZ BIPYRAMIDAL PHENOS AND SANADINE?
FELDSPAR, NO SIGN OF BANDING IN TUFF AND VERY LITTLE
MATRIX IN CONTRAST TO PREVIOUS SECTIONS;
Leg : 21 Top/Bottom Interval(mm): 1150/1200 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 403.20
Core: 39 Top of Core Depth (m) : 402.00
Sect: 1 Top of Section Depth(m): 403.15
LITHOLOGY: NON-PUMICEOUS VOLCANICS;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : OLIVE BLACK FINE-GRAINED VOLCANIC BUT NOT PUMICE;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 403.60
Core: 39 Top of Core Depth (m) : 402.00
Sect: CC Top of Section Depth(m): 403.60
LITHOLOGY: RHYOLITIC LAPILLI TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : FRAGMENTS OF PUMICE AND OF VITROPHYRIC RHYOLITE,
SOME SECONDARY HEMATITE, FRAGMENTS HAVE SIZES UP TO
8MM;
Leg : 21 Top/Bottom Interval(mm): 770/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 412.50
Core: 40 Top of Core Depth (m) : 411.00
Sect: 1 Top of Section Depth(m): 411.77
LITHOLOGY: RHYOLITE VITRIC (PUMICE) LAPILLI TUFF;
Piece No. : PCE ON PCE NUMBERS ASSIGNED;
Comments : OLIVE GRAY 5Y4/1 TO OLIVE BLACK 5Y2/1, DIFFERS FROM
OVERLYING TUFF BY PREDOMINANCE OF PUMICE FRAGMENTS
BUT HAS IN ADDITION 5-10% TUFF (LITHIC) FRAGMENTS
AND SOME BLACK OBSIDIAN, CELLULAR TEXTURE IN PUMICE
FRAGMENTS, GNDMASS HAS QTZ AND FELDSPAR GRAINS AND
ASH BUT NO GREAT AMOUNT OF GLASS AS IN PREVIOUS
CORE, STRONGLY DEVELOPED LAYERING IN THE TUFF OF
ABOUT 50-60 DEGREES, OLIVE BLACK NEAR TOP TO OLIVE
GRAY NEAR BASE;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 420.10
Core: 41 Top of Core Depth (m) : 420.00
Sect: CC Top of Section Depth(m): 420.10
LITHOLOGY: RHYOLITIC LAPILLI TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : FRAGMENTS (UP TO 4CM) OF BLACK GLASS WITH FLUIDAL
BANDING, SOME SECONDARY HEMATITE;
Leg : 21 Top/Bottom Interval(mm): 860/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 433.50
Core: 42 Top of Core Depth (m) : 432.00
Sect: 1 Top of Section Depth(m): 432.86
LITHOLOGY: RHYOLITE LAPILLI TUFF;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : NOTE: 86-130CM MAY REPRESENT OXIDIZED AND CHERTIFIED
TOP OF RHYOLITE FLOW, SOME OF THE TUFFACEOUS ROCKS
IN HIGHER SECTIONS MAY ALSO BE RHYOLITE FLOWS BUT
WITH TUFF INCLUSIONS, INTERVAL (86-104) IS GREENISH
GRAY 5GY6/1 AND MODERATE BROWN 5YR4/4 VERY FINE
GRAINED TO GLASSY RHYOLITE LAPILLI TUFF, IRON OXIDE
GRANULES STAIN ROCK BROWN, INTERVAL (104-130) IS
DUSKY BROWN 5YR2/2 AND LIGHT GREENISH GRAY 5GY8/1
VERY WELL LAMINATED WITH COLOR BANDS 2-15MM AND
DIPPING 45 DEGREES, ROCK IS LARGELY CHALCEDONY WITH
BOTRYOIDAL TEXTURE, QTZ AND FELDSPAR RELIEF PHENOS
SUGGEST ROCK IS A RHYOLITE ENRICHED IN SECONDARY
CHALCEDONY, AT 130CM GRADATIONAL CONTACT, INTERVAL
(130-150) OLIVE BLACK VOLCANIC GLASS WITH PHENOS OF
FELDSPAR AND QTZ AND WITH ABUNDANT VESICLES FILLED
BY CHALCEDONY AND SOME GREEN CHLORITIC MINERALS,
RHYOLITE PITCHSTONE WITH FLOW BANDING;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 435.00
Core: 42 Top of Core Depth (m) : 432.00
Sect: 2 Top of Section Depth(m): 433.50
LITHOLOGY: RHYOLITE;
INTERVAL (0-61) IS RHYOLITE PITCHSTONE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : INTERVAL (0-61) HAS GLASS GNDMASS WITH PERLITIC AND
CONCHOIDAL TEXTURES, INTERVAL (61-150) IS FINE-
GRAINED;
Structure : FRACTURES AND SOME GREEN SECONDARY CHLORITE MINERAL
VEINLETS AND 45 DEGREE LAMINATION PRESENT IN
INTERVAL (0-61), INTERVAL (61-150) IS STRUCTURELESS;
Alteration : INTERVAL (61-150) IS ALTERED RHYOLITE AND IS
ESSENTIALLY AN ALTERED RHYOLITE GLASS;
Comments : INTERVAL (61-150) IS DARK GREENISH GRAY 5GY4/1 TO
GREENISH GRAY 5GY6/1
Phenocrysts: FELDSPAR
QUARTZ
Groundmass : GLASSY GNDMASS IN INTERVAL (0-61);
Replacement: CHLORITE
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 442.50
Core: 43 Top of Core Depth (m) : 441.00
Sect: 1 Top of Section Depth(m): 441.00
LITHOLOGY: RHYOLITE;
SAME AS IN LOWER PART OF SECTION 42-2;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : RHYOLITE GLASS;
Structure : FAINT LAMINATIONS DIP 60 DEGREES, NOT AN ALTERED
TUFF BUT A FLOW;
Alteration : ALTERED;
Comments : GREENISH GRAY;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 442.60
Core: 43 Top of Core Depth (m) : 441.00
Sect: CC Top of Section Depth(m): 442.60
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Leg : 21 Top/Bottom Interval(mm): 0/ 100 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 450.10
Core: 44 Top of Core Depth (m) : 450.00
Sect: 1 Top of Section Depth(m): 450.00
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : QTZ+FELDSPAR PHENOS IN AN IRON.OX RICH GLASS
(POSSIBLY LEVITIFIED);
Comments : COLOR IS GRAYISH RED 5R4/2 (WET);
Phenocrysts: QUARTZ
FELDSPAR
Replacement: CHALCEDONY
CHALC FILLINGS ABUNDANT;
Leg : 21 Top/Bottom Interval(mm): 100/ 870 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 450.87
Core: 44 Top of Core Depth (m) : 450.00
Sect: 1 Top of Section Depth(m): 450.10
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Structure : RHYOLITE FLOW WITH BANDING INCLINED 60 DEGREES TO
HORIZONTAL;
Comments : COLOR IS MOD BROWN 5YR3/4, GRADUAL COLOR CHANGE
NEAR 62CM, INTERVAL (62-81) IS DARK REDDISH BROWN
10R3/4;
Replacement: CHALCEDONY
SECONDARY CHALC FILLINGS ABUNDANT;
Leg : 21 Top/Bottom Interval(mm): 870/1000 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 451.00
Core: 44 Top of Core Depth (m) : 450.00
Sect: 1 Top of Section Depth(m): 450.87
LITHOLOGY: RHYOLITE AND BRECCIA;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : SOME BRECCIATION ESPECIALLY IN LOWER PART AND
FRAGMENTS UP TO 1CM ACROSS, A 1CM FRAGMENT OF BLACK
PUMICE PRESENT;
Alteration : BLEACHED RHYOLITE;
Comments : COLORS PRESENT INCLUDE PALE YELLOWISH YELLOW 10Y8/2
AND LIGHT GREENISH GRAY 5GY8/1 AND PALE RED 10R6/2,
MAY MARK CONTACT OF DISCRETE FLOWS;
Leg : 21 Top/Bottom Interval(mm): 1000/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 451.50
Core: 44 Top of Core Depth (m) : 450.00
Sect: 1 Top of Section Depth(m): 451.00
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : QTZ+FELD PHENOS, GLASSY GNDMASS;
Structure : DARK REDDISH BROWN AND LIGHT GREENISH GRAY LAYERS
WITH WELL DEVELOPED LAMINATION DIPPING 60 DEGREES;
RHYOLITE FLOW;
Comments : COLOR IS DARK GREENISH GRAY 5GY4/1;
Phenocrysts: QUARTZ
FELDSPAR
Replacement: CHALCEDONY
CHALC FILLINGS;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 451.60
Core: 44 Top of Core Depth (m) : 450.00
Sect: CC Top of Section Depth(m): 451.60
LITHOLOGY: RHYOLITE;
PCE NO PCE NUMBERS ASSIGNED;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 460.50
Core: 45 Top of Core Depth (m) : 459.00
Sect: 1 Top of Section Depth(m): 459.00
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : ALTERED GLASSY GNDMASS, QTZ+FELD PHENOS PRESENT,
"SALT AND PEPPER" APPEARING TEXTURE PRODUCED BY
GLOBULES OF BLACK GLASS SURROUNDED BY ALTERED DARK
GREENISH GRAY GLASS+CHALCEDONY+OTHERS, AT 121CM
"SALT AND PEPPER" ROCK BROWN DEVITRIFIED GLASS
GLOBULES AND LIGHT DEVITRIFIED GLASS WITH MICROLITES
AND VERY SMALL TABULAR XTLS OF FELD(?), AT 0-7CM
WAVY SECONDARY PALE GREEN ALTERED GLASS AND BLACK
UNALTERED GLASS LAYER, DIP ABOUT 45 DEGREES;
Structure : RHYOLITE "FLOW" BANDING 60-75 DEGREES;
Comments : COLORS OF LAYERS ARE DARK GREENISH GRAY 5G4/1 AND
BROWNISH GRAY 5YR4/1;
Phenocrysts: QUARTZ
FELDSPAR
CLEAR, GLASSY (SANADINE?);
Replacement: CHALCEDONY
CHLORITE
IRON OXIDE
GRAINS;
Leg : 21 Top/Bottom Interval(mm): 0/ 150 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 460.65
Core: 45 Top of Core Depth (m) : 459.00
Sect: 2 Top of Section Depth(m): 460.50
LITHOLOGY: RHYOLITE;
SAME AS SECTION 45-1;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Structure : RHYOLITE FLOW;
Leg : 21 Top/Bottom Interval(mm): 150/1070 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 461.57
Core: 45 Top of Core Depth (m) : 459.00
Sect: 2 Top of Section Depth(m): 460.65
LITHOLOGY: RHYOLITE BRECCIA;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Comments : HIGHLY ALTERED AND BRECCIATED, MOST FRAGMENTS ARE
ANGULAR, VARIOUSLY ALTERED RHYOLITE SIMILAR TO
BANDED RHYOLITE FLOWS ABOVE AND BELOW THIS INTERVAL,
THIS COULD BE A BRECCIA FORMED DURING AND FLOW OF
RHYOLITE LAVA, DOES NOT APPEAR TO BE A TUFF!,
FRAGMENTS UP TO 3CM ACROSS, MOSAIC OF COLORS FROM
LIGHT GREENISH GRAY 5GY8/1 TO MOD REDDISH BROWN
10R4/6;
Leg : 21 Top/Bottom Interval(mm): 1070/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 462.00
Core: 45 Top of Core Depth (m) : 459.00
Sect: 2 Top of Section Depth(m): 461.57
LITHOLOGY: RHYOLITE AND BRECCIA;
SAME AS INTERVAL (0-15) BUT WITH BRECCIATED PARTS;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : BRECCIATED PARTS CONTAIN FLOW ROCK AND MORE HIGHLY
ALTERED GLASSY RHYOLITE;
Structure : RHYOLITE FLOW ROCK, SUBHORIZONTAL TO 45 DEGREE
DIPPING FLOW BANDS;
Alteration : HIGHLY ALTERED;
Leg : 21 Top/Bottom Interval(mm): 0/1100 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 463.10
Core: 45 Top of Core Depth (m) : 459.00
Sect: 3 Top of Section Depth(m): 462.00
LITHOLOGY: RHYOLITE AND BRECCIA;
SAME AS BOTTOM OF SECTION 45-2;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : BRECCIATED IN PART;
Structure : RHYOLITE FLOW ROCK, BANDED;
Alteration : HIGHLY ALTERED IN PARTS;
Leg : 21 Top/Bottom Interval(mm): 1100/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 463.50
Core: 45 Top of Core Depth (m) : 459.00
Sect: 3 Top of Section Depth(m): 463.10
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : PERLITIC TEXTURE AS IN OVERLYING HORIZONS WHERE
FRESH BLACK GLASS WITH PHENOS IS PRESENT;
Structure : BANDED RHYOLITE FLOW, BANDS DIP 60 DEGREES;
Alteration : ALTERED;
Comments : ROCK VARIES FROM DARK GREENISH GRAY 5GY4/1 TO LIGHT
GREENISH GRAY 5GY8/1 TO SHADES OF GRAYISH RED;
Phenocrysts: QUARTZ
FELDSPAR
PHENOS ARE WELL PRESERVED;
Groundmass : UNDER BINOCULAR MICROSCOPE GNDMASS APPEARS TO BE
COMPOSED OF BLACK (LEAST ALTERED) GLASS "GLOBULES" SURROUNDED BY MORE HIGHLY ALTERED LIGHTER COLORED
GLASSY MATERIAL THAT SUGGESTS ORIGINALLY HAD A
PERLITIC TEXTURE AS IN OVERLYING HORIZONS;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 463.60
Core: 45 Top of Core Depth (m) : 459.00
Sect: CC Top of Section Depth(m): 463.60
LITHOLOGY: RHYOLITE AND BRECCIA;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 469.50
Core: 46 Top of Core Depth (m) : 468.00
Sect: 1 Top of Section Depth(m): 468.00
LITHOLOGY: RHYOLITE AND BRECCIA;
SAME AS MOST OF SECTION 45-3 BUT COLORS SOMEWHAT
DIFFERENT;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : INTERVALS (0-60) AND (80-110) ESPECIALLY
BRECCIATED;
Structure : BANDED, FLOW BANDING PRESERVED THROUGHOUT BUT
ESPECIALLY WELL IN LOWER HALF DIPS ABOUT 60 DEGREES,
AT 70-77CM 30 DEGREE DIP;
Comments : MAINLY DARK GREENISH GRAY 5GY4/1 ALSO REDDISH BROWN
IRON OXIDE AREAS;
Replacement: IRON OXIDE
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 471.00
Core: 46 Top of Core Depth (m) : 468.00
Sect: 2 Top of Section Depth(m): 469.50
LITHOLOGY: RHYOLITE;
SIMILAR TO SECTION 46-1;
PROBABLY A RHYOLITE PITCHSTONE THAT HAS HAD MUCH
OF ITS GLASS DEVITRIFIED AND ALTERED;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : ESSENTIALLY NOT BRECCIATED, WITH ALTERED DEVITRIFIED
GLASS;
Structure : CUT BY VEINLETS OF QUARTZ AND CHALCEDONY AND PALE
GREEN AND WHITE SOFT MINERALS, DIP AT 32CM ABOUT 25
DEGREES, DIP AT 73CM ABOUT 10-15 DEGREES, DIP AT
122CM ABOUT 50 DEGREES;
Alteration : ALTERED;
Replacement: IRON OXIDE
Minerals Replaced: IRON SULPHIDES
TRACE AMOUNTS OF IRON SULPHIDES ALTERED IN PART
TO IRON OXIDES;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 472.50
Core: 46 Top of Core Depth (m) : 468.00
Sect: 3 Top of Section Depth(m): 471.00
LITHOLOGY: RHYOLITE;
SIMILAR TO SECTIONS 46-1 AND 46-2;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : A RHYOLITE PITCHSTONE THAT HAS QUARTZ AND FELDSPAR
PHENOS, "SALT AND PEPPER" APPEARING TEXTURE
REFLECTED IN BLACK GLASS IS MORE ALTERED GLASS
MATRIX, NOT BRECCIATED;
Structure : BANDED, 10-15 DEGREE DIPPING IN INTERVAL (0-37), AT
38CM SUBHORIZONTAL BANDING, AT INTERVAL (93-95)
PITCHSTONE LESS ALTERED BANDS (3-5MM TO 1CM WIDE),
AT 120CM PITCHSTONE BAND;
Alteration : ALTERED, MUCH OF RHYOLITE PITCHSTONE GLASS
ALTERED;
Phenocrysts: QUARTZ
FELDSPAR
RHYOLITE PITCHSTONE WITH QTZ+FELD PHENOS;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 474.10
Core: 46 Top of Core Depth (m) : 468.00
Sect: CC Top of Section Depth(m): 474.10
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Leg : 21 Top/Bottom Interval(mm): 1300/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 478.50
Core: 47 Top of Core Depth (m) : 477.00
Sect: 1 Top of Section Depth(m): 478.30
LITHOLOGY: RHYOLITE PITCHSTONE AND RHYOLITE BRECCIA;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : PERLITIC RHYOLITE PITCHSTONE WITH BRECCIATED PARTS
OF ALTERED RHYOLITE;
Alteration : FAIRLY FRESH;
Comments : BLACK;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 480.00
Core: 47 Top of Core Depth (m) : 477.00
Sect: 2 Top of Section Depth(m): 478.50
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : FINE-GRAINED GLASSY GNDMASS;
Structure : GENERALLY BANDED IN INTERVAL (75-140) 75 DEGREE TO
SUBVERTICAL DIP OF BANDS, IN INTERVAL (45-75) 15-20
DEGREE DIP AND IN INTERVAL (0-45) 60 DEGREE DIP, AT
75CM THIN WHITE VEINLET CONTAINING QTZ;
Alteration : ALTERED;
Comments : AT (141-150) SOME BRECCIATION, INTERVAL (0-45) IS
MOTTLED LIGHT GREENISH GRAY 5GY8/1 AND BACK N2
WITH MOD BROWN 5YR3/4 LAYERS, INTERVAL (45-75) IS
LIGHT GREENISH GRAY 5GY8/1 AND GRAYISH RED 5R4/2;
Phenocrysts: QUARTZ
FELDSPAR
FINE-GRAINED GLASSY ALTERED GNDMASS WITH QUARTZ+
FELD PHENOS;
Replacement: QUARTZ
IN THIN VEIN;
Leg : 21 Top/Bottom Interval(mm): 0/ 0 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 481.60
Core: 47 Top of Core Depth (m) : 477.00
Sect: CC Top of Section Depth(m): 481.60
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Structure : SOME VEINLETS WITH SECONDARY HEMATITE;
Replacement: HEMATITE
SECONDARY HEMATITE IN VEINLETS;
Leg : 21 Top/Bottom Interval(mm): 950/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 487.50
Core: 48 Top of Core Depth (m) : 486.00
Sect: 1 Top of Section Depth(m): 486.95
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : NO SIGN OF BRECCIATION, GNDMASS IS VERY FINE-GRAINED
AND APHANITIC;
Structure : HOMOGENEOUS;
Alteration : ALTERED;
Comments : INTERVAL (95-116) IS MOTTLED AND MOD YELLOW GREEN
5GYR6/6, INTERVAL (116-150) IS MOTTLED AND DUSKY
RED 5R3/4 AND PALE OLIVE 10Y6/2;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 489.00
Core: 48 Top of Core Depth (m) : 486.00
Sect: 2 Top of Section Depth(m): 487.50
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : QTZ+FELD PHENOS PRESENT, BOTRYOIDAL TEXTURE;
Structure : HOMOGENEOUS BANDED FLOW(?) ROCK;
Alteration : ALTERED;
Comments : DUSKY RED TO MOD RED 5R4/6 MOTTLING AT (0-20) AND
(120-130);
Phenocrysts: COMBINATION ( <2%)
QTZ+FELD;
Replacement: CHALCEDONY
ABUNDANT SECONDARY CHALC;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 490.50
Core: 48 Top of Core Depth (m) : 486.00
Sect: 3 Top of Section Depth(m): 489.00
LITHOLOGY: RHYOLITE;
VERY SIMILAR TO SECTION 48-2;
Piece No. : PCES NO PCE NUMBERS ASSIGNED;
Texture : GLASSY GNDMASS HAS DARK GLOBULES THAT MAY REFLECT
MICRO-PERLITIC TEXTURE OR CLUSTER OF MICROLITE XTLS;
Structure : WHITE AND MOD REDDISH BROWN TO DUSKY RED VEINLETS,
IN INTERVAL (0-43) SUBVERTICAL LAMINAE;
Comments : INTERVAL (0-36) IS DARK GREENISH GRAY 5G4/1,
INTERVAL (36-90) IS PALE YELLOWISH GREEN 10GY7/1,
INTERVAL (90-150) IS DARK GREENISH GRAY 5G4/1;
Groundmass : MICROLITE
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 492.00
Core: 48 Top of Core Depth (m) : 486.00
Sect: 4 Top of Section Depth(m): 490.50
LITHOLOGY: RHYOLITE;
SIMILAR TO SECTION 48-3;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : GLASSY GNDMASS;
Structure : REDDISH VEINS, HOMOGENEOUS, AT TOP OF SECTION DIP
OF LAMINAE 50-60 DEGREES;
Comments : INTERVAL (0-57) IS DARK GREENISH GRAY 5G4/1,
INTERVAL (57-75) IS LIGHT GREENISH GRAY 5GY8/1,
INTERVAL (75-100) IS DARK GREENISH GRAY 5G4/1,
INTERVAL (100-120) IS VERY FAINT LIGHT GREENISH
GRAY, INTERVAL (120-133) IS DARK GREENISH GRAY,
INTERVAL (133-141) IS LIGHT GREENISH GRAY, INTERVAL
(141-150) IS DARK GREENISH GRAY, REDDISH MOTTLES;
Groundmass : MICROLITE
WHITE CLOUDY OVAL AREAS THAT MAY BE CLUSTERS OF
MICROLITES;
Leg : 21 Top/Bottom Interval(mm): 0/1500 Analyst: Churkin, M.
Hole: 207A Sample Midpoint (m) : 493.50
Core: 48 Top of Core Depth (m) : 486.00
Sect: 5 Top of Section Depth(m): 492.00
LITHOLOGY: RHYOLITE;
Piece No. : PCE NO PCE NUMBERS ASSIGNED;
Texture : VERY FINE-GRAINED, PHENOS PRESENT;
Structure : HOMOGENEOUS, DUSKY RED VEINS IN INTERVAL (0-107),
BETWEEN 0-39CM 50-60 DEGREES 3-4MM WIDE LAMINAE,
BETWEEN 39-65CM DIP OF LAMINAE SET BY SMALL FAULTS
3MM OFFSET, BETWEEN (65-100) 3-4MM WIDE LAMINAE
AT 50-60 DEGREES, BETWEEN (100-150) BROADLY BANDED
AND LESS DISTINCT AT 50-60 DEGREES;
Comments : INTERVAL (0-108) IS GREENISH GRAY 5GY6/1 TO DARK
GREENISH GRAY 5GY4/1, INTERVAL (108-150) IS LIGHT
GREENISH GRAY 5GY8/1 WITH GRAYISH ORANGE PINK AND
MODERATE RED 10R8/2, ALL COLORS ARE ON WET SURFACES;
Phenocrysts: OTHER ( <2%)
MINERAL NOT SPECIFIED;
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