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Core data from the Ocean Drilling Program legs 101-129
leg : 105 section: 02 unit/subunit : 0004
hole: 0647A top int: 32 cm observer code: KUE
core: 071R pieces : 71r-2, 32 cm to 71r-3, 110 cm
rock name: FINELY CRYSTALLINE, APHYRIC BASALT.
contact : see comments
***** MAIN COMMENTS *****
With scattered < 1 mm vesicles filled with chlorite and calcite. The most
striking feature is stockwork veins of calcite and chlorite which are < 5
mm wide. The rocks are greenish gray (5G 5/1). No obvious alteration is
observed. This unit is probably part of a thin flow because it is so finely
crystalline. No salvages are present. Fracture: Some of which are filled
(veins). Grain size coarsens downward.
***** PHENOCRYSTS *****
see comments
***** GROUNDMASS *****
see comments
***** COLOR *****
see comments
***** VESICLES *****
see comments
***** STRUCTURE *****
see comments
***** ALTERATION *****
see comments
***** VEINS/FRACTURES *****
H=20, v=3. Section 647A-71R-4, greenish gray (5G5/1) with very rare
vesicles 1 mm in diameter which are partly filled with calcite. Very
few altered veins, frequent horizontal veins up to 3 mm thick. A few
vertical veins are present with occasional veins up to 1 mm thick.
Both types are filled with: a. calcite (dominant) b. chlorite
(abundant) c. pyrite (common). Thirty-one horizontal or almost
horizontal fractures (veins filled). One to two nEarly vertical
fractures, rest see comments.
leg : 105 section: 02 unit/subunit : 0001
hole: 0647A top int: 73 cm observer code: KUE
core: 071R pieces : 2
rock name: COARSELY CRYSTALLINE CALCITE AND CHLORITE
contact : see comments
***** MAIN COMMENTS *****
Occurring as a hydrothermal meshwork of radiating white crystals and veins,
which surround irregular fragments (2-3 cm in diameter) with internal
large-scale spherulitic texture. These appear glassy on uncut surfaces. The
color is pale gray to white. Basement rock was recovered at the bottom of
this core in section 647A-71R-2.
***** PHENOCRYSTS *****
see comments
***** GROUNDMASS *****
see comments
***** COLOR *****
see comments
***** VESICLES *****
see comments
***** STRUCTURE *****
see comments
***** ALTERATION *****
Strong, with numerous crosscutting veins, devitrification of fragments,
soft chlorite and calcite hydrothermal void filling.
***** VEINS/FRACTURES *****
I = 2.
leg : 105 section: 02 unit/subunit : 0002
hole: 0647A top int: 82 cm observer code: KUE
core: 071R pieces : 2
rock name: APHYRIC FINELY CRYSTALLINE (UPPER CONTACT) TO SPHERULITIC OR
VARIOLITIC.
contact : see comments
***** MAIN COMMENTS *****
(< 1 mm variolites) basalt with large calcite-filled vesicles (0.7 x 2 cm
maximum). Cross-cutting vein breaks through top, which has a botryoidal,
laminated crust, 0.1-0.5 mm thick. Top 1 cm seems to be a chilled margin.
This unit is probably a flow, with original glassy top. Large fragments in
Unit 1 are probably flow-top breccia. Crystallinity: Aphanitic to finely
crystalline and variolitic. Top could be pillow salvage.
***** PHENOCRYSTS *****
Absent.
***** GROUNDMASS *****
see comments
***** COLOR *****
Dark greenish gray (5BG 4/1)
***** VESICLES *****
To 2 cm long and < 1 cm high, filled with calcite and chlorite.
***** STRUCTURE *****
see comments
***** ALTERATION *****
Little apparent, except for crosscutting vein of chlorite.
***** VEINS/FRACTURES *****
see comments
leg : 105 section: 02 unit/subunit : 0003
hole: 0647A top int: 82 cm observer code: KUE
core: 071R pieces : 2A-2B
rock name: TALC-OR PYROPHYLLITE - BEARING BASALT.
contact : see comments
***** MAIN COMMENTS *****
This rock may be the altered equivalent of UNIT 4 below.
***** PHENOCRYSTS *****
see comments
***** GROUNDMASS *****
see comments
***** COLOR *****
Greenish gray (5BG 5/1) with a chalky luster
***** VESICLES *****
percent: n/a
size: up to < 5 mm
shape: n/a
distribution: n/a
***** STRUCTURE *****
see comments
***** ALTERATION *****
Strong
***** VEINS/FRACTURES *****
V = 1. The material is strongly altered by veins of calcite
leg : 105 section: CC unit/subunit : 0005
hole: 0647A top int: 0 cm observer code: KUE
core: 071R pieces : 1-3
rock name: APHYRIC, FINE-GRAINED BASALT
contact : n/a
***** MAIN COMMENTS *****
***** PHENOCRYSTS *****
n/a
***** GROUNDMASS *****
n/a
***** COLOR *****
Dark gray to dark greenish gray
***** VESICLES *****
None Observed
***** STRUCTURE *****
n/a
***** ALTERATION *****
Very slightly altered to unaltered
***** VEINS/FRACTURES *****
percent: n/a
size: 3 mm thick vein
orientation: Horizontal vein, vertical fracture
One vein filled with calcite; One fracture
leg : 105 section: 01 unit/subunit : 0001
hole: 0647A top int: 0 cm observer code: KUE
core: 072R pieces : 72R-1, 0 cm to 72R-3, 10 cm
rock name: FINE-GRAINED APHYRIC BASALT
contact : see comments
***** MAIN COMMENTS *****
Section 647A-72R-2 Phenocrysts: pyroxene less than 1% at 1 mm thickness.
Fracturing: SV1,14 1a-8-16 cm; multiple highly fractured veins with
different greenish minerals and quartz and pyrite.
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene < 1 Up to 1 mm in
diameter
***** GROUNDMASS *****
see comments
***** COLOR *****
Gray (2.5Y N5).
***** VESICLES *****
see comments
***** STRUCTURE *****
see comments
***** ALTERATION *****
No visible alteration.
***** VEINS/FRACTURES *****
SH = 3; I = 10; SV = 1. 1a: talc-filled vein on the bottom 6 mm. 1a:
strongly altered, greenish mixture of different minerals strongly
fractured. 2a: 2-5 mm subhorizontal veins of talc-rich material.
Inclined veins are dominantly filled by calcite; in some cases with
slip striae and pyrite crystals.
leg : 105 section: 01 unit/subunit : 0002
hole: 0647A top int: 10 cm observer code: KUE
core: 072R pieces : 72R-3, 10 cm to 72R-4, 25 cm.
rock name: FINE-GRAINED, SPARSELY PHYRIC, BASALT.
contact : n/a
***** MAIN COMMENTS *****
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene 2 0.5-2 mm
***** GROUNDMASS *****
n/a
***** COLOR *****
(2.5Y N5) gray.
***** VESICLES *****
n/a
***** STRUCTURE *****
n/a
***** ALTERATION *****
n/a
***** VEINS/FRACTURES *****
V = 0; 19; H1; 2 are filled with calcite (0.5 mm).
leg : 105 section: 04 unit/subunit : 0003
hole: 0647A top int: 25 cm observer code: KUE
core: 072R pieces : 4
rock name: FINE-MEDIUM-GRAINED MODERATE PHYRIC BASALT.
contact : n/a
***** MAIN COMMENTS *****
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene < 10 n/a
***** GROUNDMASS *****
n/a
***** COLOR *****
(2.5Y N5)gray.
***** VESICLES *****
n/a
***** STRUCTURE *****
n/a
***** ALTERATION *****
n/a
***** VEINS/FRACTURES *****
H = 0; I = 7; V = 0.
leg : 105 section: 04 unit/subunit : 0004
hole: 0647A top int: 113 cm observer code: KUE
core: 072R pieces : 4
rock name: FINE-GRAINED, SPARSELY PHYRIC, BASALT.
contact : n/a
***** MAIN COMMENTS *****
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene 2 0.5-2 mm
***** GROUNDMASS *****
n/a
***** COLOR *****
n/a
***** VESICLES *****
n/a
***** STRUCTURE *****
n/a
***** ALTERATION *****
n/a
***** VEINS/FRACTURES *****
n/a
leg : 105 section: 01 unit/subunit : 0001
hole: 0647A top int: 0 cm observer code: KUE
core: 073R pieces : 73R-1, 0 cm to 73R-6, 54 cm.
rock name: MEDIUM-GRAINED, SPARSELY PYROXENE-PHYRIC MASSIVE BASALT.
contact : see comments
***** MAIN COMMENTS *****
Section 73R-5: Some horizontal fine fractures; one large vertical fracture
from 0-60 cm.
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene 2 0.5-1.5 mm
Pyroxene 1 0.5-1.5 mm Section 73R-3; 1a, 31 cm
concentrated band of phenocrysts
Pyroxene 2 1 mm Section 73R-5
***** GROUNDMASS *****
see comments
***** COLOR *****
Gray
***** VESICLES *****
Absent. Section 73R-3: Rare irregular vesicles filled with
phyllosilicates and calcite.
***** STRUCTURE *****
see comments
***** ALTERATION *****
see comments
***** VEINS/FRACTURES *****
Numerous fine, irregular, inclined, fractures. Section 73R-2: Numerous
irregular fine fractures mostly inclined to subhorizontal. 1a, 24 cm:
0.5 cm thick fracture (subhorizontal) filled with greenish minerals,
possibly chlorite. 42 cm, calcite filled fracture between 1b and 1c.
Sectio 73R-3: I=4. 1b, 48 cm, calcite filled, 1 mm thick fracture,
horizontal to inclined. Section 73R-4: SH=3, one vertical fracture in
Piece 2a and 2b on top filled with calcite. "See main comments"
leg : 105 section: 06 unit/subunit : 0002
hole: 0647A top int: 54 cm observer code: KUE
core: 073R pieces : 73R-6, 54 cm to 73R-8, 34 cm.
rock name: MEDIUM-GRAINED, MODERATELY PYROXENE PHYRIC, MASSIVE BASALT.
contact : n/a
***** MAIN COMMENTS *****
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene 5 1-2 mm
Pyroxene 3-5 1-2 mm Section 73R-7
Pyroxene 7 1-2 mm Section 73R-8
***** GROUNDMASS *****
n/a
***** COLOR *****
Gray.
***** VESICLES *****
n/a
***** STRUCTURE *****
n/a
***** ALTERATION *****
n/a
***** VEINS/FRACTURES *****
Some fine subhorizontal,irregular fractures.Section 73R-7: Some fine
irregular subhorizontal fractures 1b.one irregular inclined
fracture.Section 73R-8:Calcite filled fracture (vertical) at the
bottom from 33-150 cm;and CC, 0-11 cm (vertical).Drilling breccia
containing different pebble-sized sediment fragments from younger
lithologies above (cavings).Smear slides show nannofossils from the
Middle Eocene,which are younger than the oldest ages from the sediment
directly above the basement contact
leg : 105 section: 01 unit/subunit : 0001
hole: 0647A top int: 0 cm observer code: KUE
core: 074R pieces : 74R-1, 0 cm to 74R-8, 26 cm.
rock name: MEDIUM GRAINED, MODERATELY PYROXENE-PHYRIC, MASSIVE BASALT.
contact : see comments
***** MAIN COMMENTS *****
Section 74R-5: H=17; SH=12. Section 74R-6: H=30; SH=4. Section 74R-7: H=15;
SH=3. Section 74R-8: Two horizontal veins of chlorite/serpentine. One
vertical vein of chlorite/serpentine. 26-81 cm: drill, gravel and slurry
cavings from younger sediments. Drill, gravel and slurry cavings: 74R-9, 0-
26 cm.
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene 5 1 mm Fresh; Occur in black matrix as
well as in the gray pockets
Plagioclase? n/a Small Pockets of very light irregular
crystals in a very fine black
matrix
No vesicles. H=9; SB=3; V=7. Most veins (9) less than 1 mm; (2) ca 3
mm thick. The vein material is pyrite (abundant) calcite (very rare)
and greenish phyllosilicates. Probably chlorite and/or serpentine
(dominant).
***** GROUNDMASS *****
see comments
***** COLOR *****
see comments
***** VESICLES *****
Section 74R-2: pyrite(abundant), calcite(very rare), phyllosilicates
(dominant), probably chlorite and serpentine. Isolated grains of
pyrite, some millimeters in diameter mm in thick veins. In thin veins,
pyrite may be the dominant secondary mineral. Section 74R-3 Horizontal
fractures and veins 15) 9>1 mm. Subhorizontal fractures and veins 5)
11<1 mm. Two of the latter complex with smaller "apophyses". One
vertical vein <1 mm. Vein material see comments.
***** STRUCTURE *****
see comments
***** ALTERATION *****
see comments
***** VEINS/FRACTURES *****
Dominant: chlorite and serpentine. Abundant: pyrite a) as few mm
grains in thick veins. b) dominant in some smaller veins. Section 74R-
4: H=21; SH=2. Two of the latter complex with smaller "apophyses".
Chlorite and serpentine dominant in veins. Pyrite often concentrated
in few mm grains in bigger veins. Fractures are produced by drilling
and are almost entirely located in veins. Rest see comment.
leg : 105 section: 04 unit/subunit : 0001
hole: 0647A top int: 0 cm observer code: KUE
core: 075R pieces : 1
rock name: FINELY CRYSTALLINE, GRAY, APHYRIC BASALT.
contact : see comments
***** MAIN COMMENTS *****
Aphyric basalt with 0.5 cm clots of dark green mineral (possibly ophitic
pyroxene). No alteration, fractures, vesicles, etc.
***** PHENOCRYSTS *****
see comments
***** GROUNDMASS *****
see comments
***** COLOR *****
see comments
***** VESICLES *****
see comments
***** STRUCTURE *****
see comments
***** ALTERATION *****
see comments
***** VEINS/FRACTURES *****
see comments
leg : 105 section: 04 unit/subunit : 0002
hole: 0647A top int: 10 cm observer code: KUE
core: 075R pieces : 75R-4, 10 cm to 75R,CC, 19 cm.
rock name: MEDIUM CRYSTALLINE, GRAY, MASSIVE BASALT.
contact : see comments
***** MAIN COMMENTS *****
To microgabbro with no preferred fabric nor outsized phenocrysts. 647A-75R,
CC: Drill cuttings and one large piece of medium crystalline basalt -
microgabbro as in Section 4.
***** PHENOCRYSTS *****
phenocryst name % size description
Pyroxene? 20 < 1 mm Dark crystals (possibly pyroxene)
***** GROUNDMASS *****
see comments
***** COLOR *****
see comments
***** VESICLES *****
see comments
***** STRUCTURE *****
see comments
***** ALTERATION *****
see comments
***** VEINS/FRACTURES *****
percent: n/a
size: < 1 mm in thickness
orientation: Horizontal to subhorizontal
Rock is cut by veins, and filled with soft, dark green, non-fibrous
mineral (possibly Antigorite).
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These Web pages are from the Core Data from the Ocean Drilling Program Legs 101-129 CD-ROM produced in 2001 by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service, National Geophysical Data Center, and collocated World Data Center for Marine Geology and Geophysics, Boulder. Data were compiled in cooperation with the U.S. Science Support Program, the Joint Oceanographic Institutions, Inc., and the U.S. National Science Foundation. Please see the NGDC privacy, disclaimer, and copyright notices. Additional ocean drilling data are available from NGDC and from the ODP/IODP.
questions to: carla.j.moore@noaa.gov