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Core data from the Ocean Drilling Program legs 101-129
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0029
hole: 648B top int: 068 cm observer code: DIV
core: 008R pieces: 010
rock name: Moderately plagioclase olivine phyric basalt
texture: Intergranular, glomeroporphyritic
where sampled: Unit 29, Pillow or flow interior;(cont.)
grain size: Fine grained
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.2-0.8
morphology : Anhedral-euhedral
***** GROUNDMASS *****
Plagioclase present % 42 original % 42 size 0.1
****** VESICLES *****
Type: Vesicles %: 0
****** SECONDARY MINERALIZATION ******
mineral name: Clays percent: <1
replacement: Mesostasis
comments : Mesostasis altered to olive green clay
with perceptible birefringence. Affects
75% of mesostsis within halo area. Bright
red and transitional brown-orange types
of alteration (Fe hydroxides) also
present.
****** OVERALL COMMENTS ******
WHERE SAMPLED CONTINUED: intersects alteration halo. MAIN COMMENTS: Plag
compositions determined using A-normal method.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0030
hole: 648B top int: 017 cm observer code: DIV
core: 009R pieces: 003
rock name: Sparsely plagioclase olivine phyric basalt
texture: Variolitic with some intersertal and intergranular
where sampled: Unit 30, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.15-0.30
morphology : Subhedral-euhedral
comments : Rare trapped melt inclusions.
***** GROUNDMASS *****
Elongate with hopper and swallowtail terminations
Plagioclase present % 46 original % 46 size <0.01-0.05
****** VESICLES *****
Type: Vesicles %: <1
filling : None
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
Mesostasis consists of mixture of acicular plag, plumose cpx, glass and opaques.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0031
hole: 648B top int: 069 cm observer code: DIV
core: 009R pieces: 010
rock name: Plagioclase olivine phyric basalt
texture: Variolitic/glomeroporphyritic, plumose-microlitic
where sampled: Unit 31, cut at shallow angle to halo.
grain size: Fine-medium
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.15-0.50
morphology : Subhedral
comments : Occurs only in glomerocrysts. Fresh.
***** GROUNDMASS *****
Acicular to lath-shaped. Hollow and hopper types.
Plagioclase present % 35 original % 35 size 0.5-3.0
****** VESICLES *****
Type: Vesicles %: 7
filling : Clay linings
shape : Round
Vesicles were usually impregnated with resign before sectioni g. Three types of
vesicle linings: 1) Olive-geen/brown clay lining. Non-birefringent. Occurs in two
vesicles at/near edge of the slide near a large glomerocryst. Browner band
overgrown by
****** SECONDARY MINERALIZATION ******
mineral name: Clays percent: <2
replacement: Mesostasis, plumose cpx
comments : Leading edge of dark halo shows
alteration of mesostasis to olive-green
clay (probably corresponds to thin dark
line seen on dry sawn surfaces). Clay is
non-birefringent, 2 mm from edge of halo,
clay changes gradationally from
olive-green through
****** OVERALL COMMENTS ******
GROUNDMASS CONTINUED: Spinel/magnetite, % present = 1, % original = 1, size = 5
microns, morphology = euhedral, comment; mainly in non-plumose textured areas.
VESICLE COMMENTS CONTINUED: (c) discontinuous layer of translucent isotropic "
iron hydroxide". The colors of the clay components of the vesicle linings are the
same as the clay replacing the adjacent groundmass mesostasis. Vesicle clays of
types (1) and (2) occur within 1 mm of each other. MAIN COMMENTS: Section is
half altered, half fresh. Modal % estimated for fresh part.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0031
hole: 648B top int: 080 cm observer code: DIV
core: 009R pieces: 011
rock name: Sparsely olivine plagioclase phyric basalt
texture: Intersertal to intergranular, variolitic
where sampled: Unit 31, Pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.05-0.10
morphology : Subhedral
comments : Fresh.
***** GROUNDMASS *****
Also swallowtail forms.
Plagioclase present % 40 original % 40 size 0.1-0.3
****** VESICLES *****
Type: Vesicles %: 4
filling : None
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0032
hole: 648B top int: 000 cm observer code: DIV
core: 013R pieces: 001
rock name: Moderately plagioclase olivine phyric basalt
texture: Variolitic
where sampled: Unit 32, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % 1 original % 1 size 0.1-0.5
morphology : Anhedral-euhedral
comments : Some melt inclusions.
***** GROUNDMASS *****
Hopper and swallowtail forms also present.
Plagioclase present % 20 original % 20 size 0.01-0.2
****** VESICLES *****
Type: Vesicles %: <1%
filling : Some glass
shape : Round
May be partially to completely glass-filled.
Mesostasis and plag microphenocrysts wrap around vesicles.
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
Groundmass plag described above are microphenocrysts. These are significantly
larger than the plag microlites in the mesostasis.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0032
hole: 648B top int: 011 cm observer code: DIV
core: 013R pieces: 002
rock name: Moderately olivine plagioclase phyric basalt
texture: Intergranular, variolitic
where sampled: Unit 32, pillow or flow interior
grain size: Fine to medium
***** PHENOCRYSTS *****
Olivine present % 2 original % 2 size 0.2-0.6
morphology : Anhedral-subhedral
comments : Also skeletal and fresh crystals.
***** GROUNDMASS *****
Common swallowtail. Some hopper.
Plagioclase present % 40 original % 40 size 0.04-0.25
****** VESICLES *****
Type: Vesicles %: Tr
filling : None
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0034
hole: 648B top int: 033 cm observer code: DIV
core: 015R pieces: 015
rock name: Sparsely plagioclase olivine phyric basalt
texture: Variolitic, glomeroporphyritic
where sampled: Unit 34, pillow or flow interior
grain size: Microcrystalline
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.4-0.5
morphology : subhedral-euhedral
***** GROUNDMASS *****
Some crystals are skeletal.
Plagioclase present % 45 original % 45 size 0.01-0.03
****** VESICLES *****
Type: Vesicles %: <1
filling : None
shape : Round
Partially coated by cryptocrystalline materials (originally glass).
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0035
hole: 648B top int: 111 cm observer code: DIV
core: 015R pieces: 015
rock name: Moderately plagioclase olivine phyric basalt
texture: Intergranular, variolitic
where sampled: Unit 35, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % 1 original % 1 size ~0.5
morphology : Round
comments : Intergrown with plag glomerocrysts.
***** GROUNDMASS *****
Some hopper shaped crystals, intergrown with cpx.
Plagioclase present % 46 original % 46 size ?
****** VESICLES *****
Type: Vesicles %: 5
filling : None
shape : Round
Contain dark fine-grained partial linings. May be a filling by late stage
residual liquid. In all vesicles, the partial lining is on the same side.
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0035
hole: 648B top int: 120 cm observer code: DIV
core: 015R pieces: 016
rock name: Sparse olivine plagioclase phyric basalt
texture: Intergranular, variolitic
where sampled: Unit 35, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.2-0.3
morphology : Euhedral-subhedral
comments : Some glass inclusions.
***** GROUNDMASS *****
Also acicular, hopper, and swallowtail crystal forms.
Plagioclase present % 45 original % 45 size 0.05-0.50
****** VESICLES *****
Type: Vesicles %: 5
filling : None
shape : Round
Spinel (?) crystallized on the edge of one vesicle.
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0035
hole: 648B top int: 002 cm observer code: DIV
core: 016R pieces: 001
rock name: Moderately plagioclase olivine phyric basalt
texture: Glomeroporphyritic, intersertal and intergranular
where sampled: Unit 35, cut perpendicular to alteration
grain size: Fine-medium
***** PHENOCRYSTS *****
Olivine present % 1.5 original % 1.5 size 0.1-0.6
morphology : Subhedral
comments : Occur in ol-plag glomerocrysts.
***** GROUNDMASS *****
Mainly hollow lath-shaped to acicular.
Plagioclase present % 33 original % 33 size 0.1-1.0
****** VESICLES *****
Type: Vesicles %: 10
filling : +/- Clay
shape : Round
Vesicles generally empty. The two that are connected by the shorter fracture
mentioned above are lined with Fe hydroxide, +/- thin clay. Some plucking of
vesicle linings from the section may have occured. Three vesicles have a
near-glass lining on
****** SECONDARY MINERALIZATION ******
mineral name: Clays percent: 1.5
replacement: Mesostasis
comments : Within the halo area, intersertal
mesostasis is partially to completely by
yellow clay or orange-red Fe hydroxide.
This alteration is confined to a fe
****** OVERALL COMMENTS ******
PLAGIOCLASE PHENOCRYST COMMENTS CONTINUED: (resmbling groundmass plag). MAIN
COMMENTS: Vesicle and phenocryst abundances visually estimated.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0036
hole: 648B top int: 048 cm observer code: DIV
core: 016R pieces: 005
rock name: Moderately plagioclase olivine phyric basalt
texture: Intergranular
where sampled: Unit 36, pillow or flow interior
grain size: Fine-medium
***** PHENOCRYSTS *****
Olivine present % 2 original % 2 size 0.05-0.07
morphology : Euhedral-anhedral
comments : Forms glomerocrysts with plag. Various skeletal
shapes.
***** GROUNDMASS *****
Blade-like intergrowth with plag or isolated.
Olivine present % 1 original % 1 size 0.01-0.05
****** VESICLES *****
Type: Vesicles %: 0.6
filling : None
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
Point count: 1000 points, 0.5 mm grid. Some glomerocryst show a radial pattern.
Generally, plag is the dominant phase in glomerocrysts, forming sub-ophitic-like
intergrowths with or wrapping around ol grains.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0036
hole: 648B top int: 088 cm observer code: DIV
core: 016R pieces: 009
rock name: Highly olivine plagioclase phyric basalt
texture: Intergranular, glomeroporphyritic
where sampled: Unit 36, pillow or flow interior
grain size: Fine-medium
***** PHENOCRYSTS *****
Olivine present % 5 original % 5 size 0.1-0.8
composition: Fo 79
morphology : Anhedral-subhedral
comments : Occurs mostly in plag-olivine glomerocrysts.
Meltinclusions.
***** GROUNDMASS *****
Hopper and swallowtail forms also present.
Plagioclase present % 35 original % 35 size 0.01-0.20
****** VESICLES *****
Type: Vesicles %: <1
filling : None
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
Plag has seriate grain size distribution. Range of grain sizes quoted above for
"groundmass" plag includes both small, acicular plag in Ol composition determined
by XRD.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0038
hole: 648B top int: 022 cm observer code: DIV
core: 017R pieces: 005
rock name: Moderately plagioclase olivine phyric basalt
texture: Intergranular, glomeroporphyritic
where sampled: Unit 38, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % 2 original % 2 size 0.1-0.4
composition: Fo 80
morphology : Subhedral-anhedral
comments : In glomerocrysts with plag.
***** GROUNDMASS *****
Also acicular, swallowtail, and hopper forms present.
Plagioclase present % 42 original % 42 size 0.02-0.15
****** VESICLES *****
Type: Vesicles %: 0
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0040
hole: 648B top int: 000 cm observer code: DIV
core: 018R pieces: 001
rock name: Sparsely plagioclase olivine phyric basalt
texture: Seriate, sub-ophitic
where sampled: Unit 40, alteration halo
grain size: Medium
***** PHENOCRYSTS *****
Olivine present % 0.5 original % 0.5 size 0.5-1.0
morphology : Equant, anhedral
comments : In poorly defined glomerocrysts.
***** GROUNDMASS *****
Equant to sub-poikilitic, elongated parallel to C axis.
Olivine present % 5 original % 5 size 0.2-1.5
****** VESICLES *****
Type: Vesicles %: <0.5
filling : Clay linings
shape : Round
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments : Alteration minerals, from edge of halo
inward toward site of fracture: 1) Small
amounts of olive-green, low-birefringent
clay. Partially replaces mesostasis, with
an associated more general brown
discoloration of the mesostasis.
****** OVERALL COMMENTS ******
Interesting groundmass textures: 1) Elongate ol in optical continuity extended
for up to 3 mm parallel to the c-axis, forming sub-poikilitic relationship to
plag. Locally overgrown by intergranular cpx in near optical continuity with ol.
Similar elongated ol extends in continuity from the 1 mm equant ol phenocryst,
with rods of the same crystal extending 0.1 mm into enclosing cpx and plag (cpx
is not in optical relation to ol). Some ol ,oikocrysts partially enclose and
interpenetrate a plag lath orientated parallel to the c-axis of ol. More equant,
sub-poikilitic to intergranular ol is common in the vicinity of the 1-mm sized ol
phenocryst. 2) "bow-tie" structures: rare occurance defined by intersecting plag
laths and by a gap in plag enclosed in ol oikocryst. 3) Rare hollow subhedral
olivine crystals enclosing plag and mesostasis.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0040
hole: 648B top int: 038 cm observer code: DIV
core: 018R pieces: 002
rock name: Sparsely plagioclase olivine phyric basalt
texture: Intergranular, intersertal, hypocrystalline
where sampled: Unit 40, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.1-0.6
morphology : Anhedral-subhedral
***** GROUNDMASS *****
Tabular
Plagioclase present % 43 original % 43 size 0.01-0.04
****** VESICLES *****
Type: Vesicles %: 0
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
GROUNDMASS CONTINUED: Spinel % present = << 1, % original = << 1, size = 0.05 mm,
morphology = euhedral. MAIN COMMENTS: Needles of plag and cpx are enclosed in
pools of glass.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0040
hole: 648B top int: 013 cm observer code: DIV
core: 019R pieces: 026
rock name: Sparsely plagioclase olivine phyric basalt
texture: Intergranular
where sampled: Unit 40, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size <0.5
morphology : Rounded, skeletal
***** GROUNDMASS *****
Also subhedral morphology. Grains measured perpendicular to (010).
Plagioclase present % 44 original % 44 size 0.02-0.10
****** VESICLES *****
Type: Vesicles %: 0
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL COMMENTS ******
Point count: 1000 points, 0.5 mm grid.
ODP hard-rock thin section description - verbose form
leg : 109 section: 01 unit/subunit : 0041
hole: 648B top int: 048 cm observer code: DIV
core: 020R pieces: 006
rock name: Sparsely plagioclase olivine phyric basalt
texture: Trachytic, pilotaxitic
where sampled: Unit 41, pillow or flow interior
grain size: Fine
***** PHENOCRYSTS *****
Olivine present % <1 original % <1 size 0.1-0.3
morphology : Subhedral-anhedral
comments : In glomerocrysts with plag.
***** GROUNDMASS *****
Lenfth:width = 1:10 to 1:40. Subparallel alignment.
Plagioclase present % 45 original % 45 size 0.01-0.07
****** VESICLES *****
Type: Vesicles %: 0
****** SECONDARY MINERALIZATION ******
mineral name: percent:
replacement:
comments :
****** OVERALL 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