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Core data from the Ocean Drilling Program legs 101-129
leg : 103 section: 03 unit/subunit : 0001
hole: 0637A top int: 37 cm observer code: DU
core: 023R pieces : 1-6.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
Basement rock was recorved at the bottom of this core in Section 637A-23R-
3, which includes 20 cm of yellow-red mud overlying about 80 cm of
extreamly altered foliated harzburgite. The rock grades from a very leached
yellow rock with elongated dissolution cavities along the foliation (at a
angle of 30 degrees) to a more massive, strongly foliated green-gray
peridotite. The rock is almost completely serpentinized and extensively
replaced by calcite (>75% in the top few cm); vertical calcite veins are
abundant near the bottom of the core, and calcite rims and replaces the
pyroxene porphyroclasts. The freshest samples (637A-23R-3R, 37-40 cm and
46-48 cm) have a few relict mineral fragments (opx, cpx, chromite). The
rocks are 75-80% olivine, 10-15% opx, 0-5% cpx and 1-2% chromium spinel.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 024R pieces : 1-5.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
Coarse porphyroclastic harzburgite with foliation defined by the alignment
of oval-shaped orthopyroxene and chromium spinel. The rock is cut by thick
(1-2.5 cm) dia gonal and vertical calcite veins which appear to become more
regularly spaced downcore. The bottom of Section 637A-1 and top of 637A-2
include pink-gray mud and sand with Miocene discoasters. The rock is almost
completely altered (95-100%) to serpentine. A few fragments of pyroxene
porphyroclasts remain. Abundant thin calcite veins dissect the rock. The
rock is a pyroxene-poor harzburgite with 90% serpentine derived from
olivine, < 10% orthopyroxene, 1-2% clinopyroxene, and 1% chromium spinel.
It is sheared, as shown by strong alongation of orthopyroxene pseudomorphs.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 60 cm observer code: DU
core: 024R pieces : 1.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-24R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-12.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
The top of this core is composed of a gray-green homogeneous foliated
peridotite which displays porphyroclastic textures. It is dissected by
small calcite veins which are oriented at a high angle to the foliation.
The calcite often contains small inclusions of magnetite. The degree of
deformation, marked by the extreme elongation of orthopyroxene, increases
downward to the middle of core. This is also the case for serpentinization
of the peridotite, and almost no relict primary phases are preserved.
Calcite veining is not as extensive, but increases again towards base of
core. The bottom sections contain pyroxene-poor harzburgite which is highly
serpentinized and brecciated; a lot of serpentine rubble was recorved, with
large (2-3 cm) calcite veins.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-2.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-25R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 03 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-11.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-25R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 04 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-5.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-25R-4.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 05 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-9.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-25R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 06 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 025R pieces : 1-4.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-25R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 026R pieces : 1-5.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
This core consists of highly altered peridotite which is variably veined by
calcite. The veining is especially notable at the top and the bottom of
core. The veins are thick, zoned, and are coarsely crystalline with comb
structures. Serpentine veining is also pervasive. The middle of core
includes massive, strongly altered and sheared, pyroxene-poor harzburgite.
The orthopyroxene, which constitutes less than 10% of rock, is highly
elongated and strained; the clinopyroxene is rounded and often replaced by
calcite. The base of the core contains brecciated serpentinite and black
serpentine rubble. Many of the cobble-sized pieces contain large calcite
veins.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 026R pieces : 1A-1H.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-26R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 03 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 026R pieces : 1-13.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-26R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 04 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 026R pieces : 1-8.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-26R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 027R pieces : 1-18.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
This core consists of moderate to highly altered and sheared peridotite
(highly altered & friable near base). Part of the recovered material
includes some coarse-grained peridotite sand (a result of drilling). The
top of the core includes cobble or smaller sized pieces of peridotite. This
becomes more massive and less altered downward. Thin sections reveal the
rock to be a pyroxene-rich harzburgite which contains more and larger
fragments of the primary minerals (mostly opx and cpx). The rock is black
in color in the middle of the core, but heavily veined with calcite. The
rock grades into a pyroxene-poor (<10%) harzburgite with local occurrences
of pyroxene-rich layers(20-25% pyroxene). Some amphibole associated with
the alteration of pyroxenes is observed. Shear zones increase downward.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 027R pieces : 1-19.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-27R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 03 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 027R pieces : 1-6.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-27R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 04 unit/subunit :
hole: 0637A top int: 40 cm observer code: DU
core: 027R pieces : 1-8.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-27R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 05 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 027R pieces : 1-12.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-27R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 06 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 027R pieces : 1-15.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-27R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 028R pieces : 1-13B.
rock name: SERPENTINIZED PORPHYROCLASTIC HARZBURGITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
This core consists of gray-green coarse to fine-grained porphyroclastic
peridotites which are pyroxene-poor(10-15% pyroxene). The apparent
foliation is about 45-50 degrees at top, steepens to 75-80 degrees mid-
core, and is near vertical at the base. The rock has a well-developed
foliation, which is evident in thin section (extreme elongation of opx,
fragmented cpx & chromium spinel crystals which are strung out along the
foliation plane). The rock becomes increasingly altered and brecciated
downsection, and virtually no relict fragments of primary minerals are
preserved. The color changes to red-green and black downsection. The
peridotite is broken into many cobble-sized pieces which have thick calcite
veins and fibrous serpentine veins.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 028R pieces : 1-14.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-28R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 03 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 028R pieces : 1-15.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-28R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 04 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 028R pieces : 1-16.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-28R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 029R pieces : 1-22.
rock name: ALTERED PERIDOTITE.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
Very friable and heaviliy altered peridotite was recorved in this core. It
is broken up into many pieces. The color changes from red-green to black
downcore. The Upper part of the core contains pieces which are cut by
abundant calcite veins, but this changes downwards into pieces with no
calcite veins where the rock has a vertical foliation and is highly
sheared. The base of the core recovered a coarse, poorly sorted peridotite
sand, which is presumably the product of drilling. No shipboard thin
section were made.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 125 cm observer code: DU
core: 029R pieces : 23.
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-29R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 01 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 030R pieces : n/a
rock name: SERPENTINE MUD.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
Only a blue-gray mud was recorved in this core. It has the composition of
serpentine (chrysotile and lizardite), and is presumably drill gouge
material.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
leg : 103 section: 02 unit/subunit :
hole: 0637A top int: 0 cm observer code: DU
core: 030R pieces : n/a
rock name: CONTINUED.
color : see comments
layering : see comments
deformation: see comments
***** MAIN COMMENTS *****
See description in 103-637A-30R-1.
***** PRIMARY MINERALS *****
primary mineral comments:
see comments
***** SECONDARY PHASES *****
phase two comments:
see comments
introduction | data types | geographic areas | legs/sites/holes | sites/holes
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