SUBJECT INDEX

A

acceleration autocorrelation, B1:12–13 spectra, B1:11 vs. depth, B1:16–17
accelerometers, amplitude spectra, A5:21
accessory minerals, gabbro, B(synthesis):9–11
actinolite alteration, A2:5 hydrothermal alteration, A4:43–44; B(synthesis):8
adcumulate fractional crystallization, A4:41–42, 47–48 gabbroic rocks, B(synthesis):18 lithology, A2:5–6 photomicrograph, A4:108, 116 structure, B(synthesis):46 See also heteradcumulate
adcumulate, poikilitic, fractional crystallization, A4:41–42
albite, photomicrograph, A4:128
alteration amphibolite gneiss, A4:9 Site 1105, A4:42–48 styles, A4:43–44 vs. depth, A4:97
aluminum false-color map in clinopyroxene, B(synthesis):84 mineral chemistry, B2:10–12 vs. magnesium number, B2:38 vs. titanium, B2:39 See also titanium/aluminum ratio
aluminum, tetrahedral vs. titanium, B(synthesis):87 vs. titanium oxide in clinopyroxene, B(synthesis):88
aluminum oxide gabbroic rocks, A4:45–47; B(synthesis):23 vs. depth, A4:123 vs. magnesium number in clinopyroxene, B(synthesis):85
amphibole, photomicrograph, A4:120; B2:33
amphibolite gneiss, composition, A4:9
amplitude, vs. depth, B1:14
anorthite cumulates, B2:52 gabbro, B2:30 histogram in plagioclase, B(synthesis):90 major elements, B2:56–60 mineral chemistry, B2:10 mole percent, B2:51 vs. augite, B2:49 vs. depth, B(synthesis):92; B2:45 vs. forsterite, B(synthesis):91; B2:49, 52 vs. magnesium number, B(synthesis):91; B2:46 vs. orthoclase, B2:35 vs. potassium oxide in plagioclase, B(synthesis):89
apatite major elements, B2:74 mineral chemistry, B2:12 phase equilibria, B2:44 photomicrograph, B2:33
apatite gabbro lithologic units, A4:31–34 petrography, A4:40–41; B2:9 photomicrograph, A4:120–121
Atlantis II Fracture Zone free-air gravity maps, A4:73 gabbro, B2:3–4 tectonics, B(synthesis):4–7
Atlantis II transform fault bathymetry, A1:14; A4:74 three-dimensional image, A4:75
Atlantis Bank bathymetry, A4:77 drilling, A1:1–26 shaded-relief image, A1:15 tectonics, A4:6–14; B(synthesis):7 three-dimensional shaded-relief image, A4:78
augite composition, B2:53–55 gabbro, B(synthesis):22–23; B2:14–16 photomicrograph, B2:29 vs. anorthite, B2:49 vs. depth, B2:47–48
Australo-Indian plate, intraplate seismicity, A5:18

B

basalt basement, A1:11–12 melts, B(synthesis):19
basement basalt, A1:11–12 core-log correlation, B3:1–29
bathymetry Atlantis II Transform Fault, A1:14; A4:74; B(synthesis):58–60 Atlantis Bank, A4:77
biotite major elements, B2:75 mineral chemistry, B2:12
boreholes, casing, A5:20
boundary layer, fractionation, B(synthesis):31
Bouvet Triple Junction, tectonics, B(synthesis):4
Broken Ridge, free-air gravity maps, A5:19
bulk density logs, vs. depth, A4:156, 159; B1:17

C

calcite amphibolite gneiss, A4:9 hydrothermal alteration, A4:43–44; B(synthesis):8
calcium, vs. iron, B2:40
calcium oxide, gabbroic rocks, A4:45–47
caliper logs, vs. depth, A4:155
cerium gabbroic rocks, B(synthesis):15 vs. cerium/ytterbium ratio, B(synthesis):79 vs. depth, B(synthesis):81, 104 vs. ytterbium, B(synthesis):79
cerium/ytterbium ratio gabbroic rocks, B(synthesis):15 vs. cerium, B(synthesis):79 vs. ytterbium, B(synthesis):79
chlorine, phase equilibria, B2:44
chlorite alteration, A2:5 hydrothermal alteration, A4:43–44; B(synthesis):8
chromium gabbro, A2:5 gabbroic rocks, A4:45–47; B(synthesis):17 mineral chemistry, B2:10–11 vs. depth, A4:125 vs. magnesium number, B2:38
chromium, whole-rock, vs. whole-rock magnesium number, B(synthesis):78
chromium oxide gabbro, B(synthesis):24, 29 vs. depth in clinopyroxene, B(synthesis):93 vs. magnesium number in clinopyroxene, B(synthesis):85
clinopyroxene alteration, A2:5 backscatter image, B(synthesis):84 cumulates, A4:42 lithologic units, A4:31–34; B(synthesis):9–11, 22–26, 44 magmatic-tectonite textures, A4:51–52 magnesium number and forsterite, B(synthesis):91 major oxides, B(synthesis):117–119 mineral chemistry, B2:10–11, 13–14 petrography, A4:38–41; B2:6–9, 14–21 photograph, A4:126, 139–140 photomicrograph, A4:113–115, 122, 133, 137–138, 141, 143 porphyroclastic textures, A4:53 veins, A4:55
clinopyroxene, elongate, photomicrograph, A4:127–128
clinopyroxene, oikocrystic, photomicrograph, A4:109, 129
clinopyroxene, poikilitic lithologic units, A4:31 photomicrograph, A1:23; A4:110
clinopyroxene-olivine-opaque minerals, modal composition, A4:107
clinopyroxene-olivine-plagioclase, modal composition, A4:107
clinopyroxene paradox, gabbro, B(synthesis):30
compressional wave velocity, vs. depth, A4:154; B1:16–17
consertal intergrowth, photomicrograph, A4:113
contacts gabbroic rocks, A4:51 photograph, A4:105, 131
copper, gabbroic rocks, A4:45–47; B(synthesis):17
copper, whole-rock, vs. whole-rock magnesium number, B(synthesis):78
core magnetic field, A4:56 paleomagnetism, A4:9
core-log correlation, oceanic basement, B3:1–29
corona structure, textures, B(synthesis):41
correlation Sites 735 and 1105, B(synthesis):64 tie points, B3:24
crust, oceanic composition, A4:47–48 ophiolite, A4:12
crust, seafloor spreading, A4:6–8
cryptic variations, gabbroic rocks, B2:12–14, 19–20, 47–48
crystal chemistry, gabbroic rocks, B(synthesis):28–30
crystallization ophiolite, A4:12, 48 quantitative model, B2:14–16
crystallization, in situ, gabbroic rocks, B(synthesis):30–34
cumulates, gabbro, A4:41–42, 47–48; B(synthesis):19–21; B2:52
cumulates, ultramafic, ophiolite, A4:12

D

deformation extent, B(synthesis):103 lithologic correlation, B(synthesis):45–46 massifs, A4:56–57; B(synthesis):34–36, 44–47 petrography, A4:38–41; B2:18 photograph, B3:19 photomicrograph, A4:132; B2:27, 29
deformation, brittle, petrography, A4:40
deformation, crystal-plastic lithology, A2:5; B(synthesis):47–49 photograph, A4:134–136, 146
deformation, ductile, lithology, A2:5; A4:47–48
deformation, high-stress crystal-plastic, strain localization, A4:53–54
deformation, melt-induced, structure, B(synthesis):46–47
deformation bands, photomicrograph, A4:111; B2:27, 29
density, bulk, gabbroic rocks, A4:63–64
depth, curated, to top of cored interval, B3:29
differentiation, magmatic veins, A4:37
diopside, quadrilateral plot, B(synthesis):86
dip azimuth, rose diagrams, B3:20
dipping layer, photograph, B3:19
downhole logging, Site 1105, A4:60–65
drilling, lithologic boundaries, B1:1–17
ductile zones, porphyroclastic textures, A4:53
dunite, ophiolite, A4:13

E

elongate minerals massifs, A4:56–57 photomicrograph, A4:127–128
enstatite, quadrilateral plot, B(synthesis):86
ephemeral chambers, ophiolite, A4:13
epidote, hydrothermal alteration, A4:43–44; B(synthesis):8
exsolution lamellae gabbro, A4:41; B(synthesis):26, 42 photomicrograph, A4:122

F

fabric gabbroic rocks, A4:50–53 massifs, A4:56–57 styles, A4:43–44 tectonics, B(synthesis):5–7
fabric, corrugation, tectonics, B(synthesis):5–7
fabric, crystal-plastic, lithology, A2:5
fabric, high-temperature crystal-plastic, gabbroic rocks, A4:52
fabric, planar, primocrysts, A4:35; B2:18
faults brittle structures, A4:54–56 tectonics, B(synthesis):5–7
faults, conjugate, tectonics, B(synthesis):6
faults, detachment massifs, A4:56 schematic model, A4:150 unroofing, A4:7 tectonics, B(synthesis):6–7
faults, normal, tectonics, B(synthesis):6
faults, ridge-parallel, tectonics, B(synthesis):6
faults, transform gabbro, B2:3–4 rift valleys, A4:6–8 tectonics, B(synthesis):5
Federation of Digital Seismic Networks, experiments, A5:17
felsic rocks, lithology, A2:4–6
ferrosilite, quadrilateral plot, B(synthesis):86
fluid inclusions, photomicrograph, A4:121
fluorine, phase equilibria, B2:44
foliation gabbroic rocks, A4:51; B(synthesis):63; B3:9 massifs, A4:56–57 photograph, B3:23 photomicrograph, A4:133; B2:27
foliation, crystal-plastic porphyroclastic, photograph, A4:134–136; B(synthesis):42
Formation MicroScanner imaging, lithology, A1:21; B(synthesis):102; B3:7–29
Formation MicroScanner imaging logs, vs. depth, A4:157–158; B(synthesis):62
forsterite cumulates, B2:52 gabbro, B2:31 histogram in olivine, B(synthesis):90 vs. anorthite, B(synthesis):91; B2:49, 52 vs. depth, B(synthesis):92 vs. magnesium number, B(synthesis):91 vs. manganese, B2:36 vs. manganese oxide, B(synthesis):83, 93 vs. nickel oxide, B(synthesis):83
fractional crystallization cumulates, A4:41–42 gabbro, B(synthesis):31–34; B2:14–21 modeling, B2:76 See also perfect fractional crystallization
fractionation boundary layer, B(synthesis):31 olivine gabbro, A4:8–9; B(synthesis):31
fracture zones gabbro, B2:3–4 tectonics, B(synthesis):5–7
fractures brittle structures, A4:54–56; B3:8–9 massifs, A4:56–57 photograph, A4:147–149; B3:17–18 photomicrograph, A4:145 tectonics, B(synthesis):6
fractures, brittle, lithology, A2:6
fractures, vein-filled, brittle structures, A4:54–56
free-air gravity maps Atlantis II Fracture Zone, A4:73; B(synthesis):57 Ninetyeast Ridge, A5:19

G

gabbro fractional crystallization, B2:14–16 lithologic units, A4:31–34 lithology, A2:4–6; B(synthesis):8 melts, B2:14–16 modal variations, B2:28 ophiolite, A4:12 petrography, A4:38–41; B2:6–9 petrology, A4:30–42; B2:1–76 photograph, A4:101–102 pseudostratigraphy, B(synthesis):7–11 quantitative model, B2:14–16 synthesis, B(synthesis):1–125 tectonics, B2:3–4 See also apatite gabbro; iron-titanium oxide gabbro; leucogabbro; microgabbro; olivine gabbro; oxide gabbro; oxide olivine gabbro
gabbro, coarse-grained lithologic units, A4:31–34 photograph, A4:130 photomicrograph, A4:132
gabbro, fine-grained, petrology, A4:30–42; B(synthesis):8
gabbro, leucocratic lithology, A2:5–6 photograph, A4:146 See also leucogabbro
gabbro, massive, photograph, A1:17–18
gabbro, medium-grained petrology, A4:30–42; B(synthesis):8 photograph, A4:103
gabbro, medium-grained granular, photomicrograph, A4:115
gabbro, meta-oxide, photograph, A4:134–136
gabbro, pegmatitic petrology, A4:30–42; B(synthesis):8 photograph, A4:130 photomicrograph, A4:114
gabbro, troctolitic, lithology, A2:4–6
gabbroic rocks exposure, A4:76 grain size, B(synthesis):7–8 modal composition, A4:107; B(synthesis):66–67 petrology, A4:30–42 rotation, A4:56 structures, A4:48–50 transform valleys, A4:7
gabbroic rocks, gneissic, photomicrograph, A4:133
gabbronorite composition, A4:9 lithology, A2:4–6 petrography, B2:8–9 petrology, A4:30–42; B(synthesis):8
gabbronorite, olivine-bearing, photomicrograph, A4:117
gain-size layering, petrology, A4:37
gamma ray logs gabbroic rocks, A4:63 vs. depth, A4:155, 157; B1:16
geochemistry gabbro, A2:5 gabbroic rocks, A4:8–9, 179–182 Site 1105, A4:45–48 synthesis, B(synthesis):1–125
geochemistry, whole-rock, gabbro, B(synthesis):11–21
geology, tectonics, B(synthesis):4–7
Geophysical Ocean-Bottom Observatory, drilling, A1:1–26
GEOSCOPE, experiments, A5:17
gneissic textures, equigranular, gabbroic rocks, A4:52
gradational contacts, petrology, A4:34–35
grain size gabbroic rocks, B(synthesis):7–8 lithologic units, A4:31–34 petrography, A4:41 photograph, A4:103 porphyroclastic textures, A4:52–53 vs. depth, A4:95–96; B2:26
granophyre, petrology, B(synthesis):8
greenschist facies, alteration, A4:44

H

halite, photomicrograph, A4:121
hammer-drilling system casing, A4:2–4, 80–86 drilling, A1:2–3; A4:1–183 engineering and scientific objectives, A4:4–5, 28–29, 165–178 photograph, A4:87–92
hedenbergite, quadrilateral plot, B(synthesis):86
hematite, phase equilibria, B2:41
heteradcumulate, fractional crystallization, A4:47
hornblende, brown hydrothermal alteration, A4:43–44; B(synthesis):8 photomicrograph, A4:108, 114 veins, A4:55
hornblende, green, hydrothermal alteration, A4:43–44
hornblende, petrography, A4:38–41
hydrothermal alteration, petrology, A4:42–44
hydroxyl ion, phase equilibria, B2:44

I

igneous banding, gabbroic rocks, A4:51
igneous contacts, petrology, A4:34–37
igneous laminations gabbroic rocks, A4:50–53 lithology, A2:5 petrology, A4:35; B(synthesis):8, 63 photomicrograph, A4:99, 127 vs. depth, A4:98
igneous petrology, A4:29–42
ilmenite composition, B(synthesis):26 major elements, B2:69–73 oxygen fugacity, B2:43 phase equilibria, B2:41 photomicrograph, B2:33
inclusions, photomicrograph, A4:117
index properties, gabbroic rocks, A4:60
Indian Ocean, seismicity, A5:18
Indian Ocean E, drilling, A1:1–26
Indian Ocean Triple Junction, tectonics, B(synthesis):4–5
intercumulus melts, gabbroic rocks, B(synthesis):35
International Ocean Network, drilling, A1:1–26
intrusive contacts, petrology, A4:34–35
iron false-color map in clinopyroxene, B(synthesis):84 mineral chemistry, B2:10–12 phase equilibria, B2:41 vs. calcium, B2:40 vs. magnesium, B2:40
iron oxide gabbro, A2:5; B2:12–21 gabbroic rocks, A4:45–47; B(synthesis):13 histogram of whole-rock distribution, B(synthesis):69 vs. depth, A4:123; B(synthesis):81; B2:45 vs. silica, B2:50
iron oxide, whole-rock, vs. whole-rock titanium oxide, B(synthesis):70
iron-titanium oxide cumulates, A4:42 gabbroic rocks, A4:30–42; B(synthesis):8 lithologic units, A4:31; B(synthesis):27–28 mineral chemistry, B2:11–12, 14–21 modal layering, A4:36–37 olivine gabbro, A2:4–6 petrography, A4:38–41; B2:6–9 photograph, A1:18; A4:102, 131 photomicrograph, A4:114, 118, 120; B2:27, 33
iron-titanium oxide gabbro, photomicrograph, B2:33
irregular contacts, petrology, A4:34–35

K

Kerguelen Plateau, free-air gravity maps, A5:19
kink band deformation photomicrograph, B2:27 textures, B(synthesis):42

L

laminations. See igneous laminations
lanthanum, gabbroic rocks, B(synthesis):15
layer contacts, petrology, A4:34–35
layered intrusions lithology, A2:4–6; B2:4–5, 17–21 ophiolite, A4:12
layering lithologic units, A4:31, 51; B(synthesis):63 petrology, A4:34–37 photograph, A4:100–103, 139–140
leucocratic layering, petrology, A4:36–37
leucogabbro veins, A4:55; B(synthesis):8 See also gabbro, leucocratic
linear structures, gabbroic rocks, A4:50–53
lithologic boundaries, drilling, B1:1–17
lithologic units gabbroic rocks, A4:31–34; B(synthesis):8–9; B2:4–5 Unit I, A4:31 Unit II, A4:31–32 Unit III, A4:32–33 Unit IV, A4:33–34
lithology deformation, B(synthesis):45–46 summary, A1:16; A4:93; B(synthesis):61
lithostratigraphy gabbro, A2:11; A4:30–34; B2:4–5, 26 Site 1105, B(synthesis):7–11

M

magma chambers gabbroic rocks, B(synthesis):33 slow-spreading centers, A4:10–13, 29–48
magma chambers, oceanic, gabbro, B2:1–76
magmatic structures, gabbroic rocks, A4:9
magmatic systems, subaxial, tectonics, B(synthesis):7
magnesium false-color map in clinopyroxene, B(synthesis):84 mineral chemistry, B2:10–12 vs. iron, B2:40 vs. manganese, B2:42
magnesium number downhole comparison of Sites 735 and 1105, B(synthesis):82 false-color map in clinopyroxene, B(synthesis):84 gabbro, A2:5; B2:12–21 gabbroic rocks, A4:8, 45–47; B(synthesis):12–13, 16–26 histogram in clinopyroxene, B(synthesis):90 histogram of whole-rock distribution, B(synthesis):68 mineral chemistry, B2:10–12 olivine, B2:66–68 pyroxene, B2:32, 61–64 vs. aluminum, B2:38 vs. aluminum oxide in clinopyroxene, B(synthesis):85 vs. anorthite, B(synthesis):91; B2:46 vs. chromium, B2:38 vs. chromium oxide in clinopyroxene, B(synthesis):85 vs. depth, A4:125; B(synthesis):81, 92, 104; B2:45 vs. forsterite, B(synthesis):91 vs. manganese, B2:38 vs. manganese oxide in clinopyroxene, B(synthesis):85 vs. nickel oxide in clinopyroxene, B(synthesis):93 vs. phosphorus oxide, B2:50 vs. sodium, B2:38 vs. sodium oxide in clinopyroxene, B(synthesis):85 vs. titanium, B2:38 vs. titanium/aluminum ratio, B2:39 vs. titanium oxide in clinopyroxene, B(synthesis):85 vs. titanium oxide in melt, B(synthesis):94
magnesium number, whole-rock vs. whole-rock chromium, B(synthesis):78 vs. whole-rock copper, B(synthesis):78 vs. whole-rock manganese oxide, B(synthesis):71 vs. whole-rock modal oxide, B(synthesis):70 vs. whole-rock nickel, B(synthesis):78 vs. whole-rock silica, B(synthesis):70 vs. whole-rock titanium oxide, B(synthesis):70–71
magnesium oxide gabbroic rocks, A4:45–47 vs. depth, A4:125
magnesium oxide, whole-rock, vs. whole-rock titanium oxide, B(synthesis):70
magnetic declination, vs. depth, A4:153
magnetic field inclination, A2:6; A4:56 Site 1105, A1:9 structures, A4:56
magnetic inclination gabbroic rocks, A4:59 schematic model, A4:150 vs. depth, A4:153
magnetic intensity, vs. depth, A4:153
magnetic susceptibility gabbroic rocks, A4:58; B3:9 pseudostratigraphy, B(synthesis):7–11 shear zones, A2:6 vs. depth, A4:94; B(synthesis):64; B2:26; B3:15–16, 25–26
magnetic susceptibility, whole-core, vs. depth, A1:22; A4:151–152
magnetite hydrothermal alteration, A4:43–44; B(synthesis):8 vs. depth, B3:25–26
major elements apatite, B2:74 biotite, B2:75 clinopyroxene, B(synthesis):117–119 comparison of plutonics of Site 1105 and basalts of Atlantis II Fracture Zone, B(synthesis):80 gabbroic rocks, A4:45–47, 179–182; B(synthesis):12–15, 27–30, 108–110 ilmenite, B2:69–73 olivine, B(synthesis):120–122; B2:66–68 plagioclase, B(synthesis):123–125; B2:56–60 pyroxene, B2:61–65 titanomagnetite, B2:69–73 vs. depth, A4:159
manganese mineral chemistry, B2:10 vs. forsterite, B2:36 vs. magnesium, B2:42 vs. magnesium number, B2:38
manganese oxide gabbroic rocks, A4:45–47; B(synthesis):14 vs. forsterite, B(synthesis):83, 93 vs. magnesium number in clinopyroxene, B(synthesis):85
manganese oxide, whole-rock, vs. whole-rock magnesium number, B(synthesis):71
mantle, tectonics, B(synthesis):7
median ridges, transform valleys, A4:7
melanocratic layering, petrology, A4:36–37
melts gabbro, B2:14–16 gabbroic rocks, B(synthesis):47–49 See also intercumulus melts
melts, trapped, cerium and magnesium number vs. depth, B(synthesis):104
mesocumulate fractional crystallization, A4:41–42 gabbroic rocks, B(synthesis):18
metamorphic petrology, A4:42–48
metamorphism gabbroic rocks, A4:9 styles, A4:43–44
mica, phlogopitic, hydrothermal alteration, A4:43–44
microcracks, crystal-plastic deformation, A4:53–54
microfractures, crystal-plastic deformation, A4:54
microgabbro gain-size layering, A4:37 petrography, B2:9 photomicrograph, B2:34
microstructure, gabbroic rocks, B(synthesis):34–35
mineral chemistry apatite, B2:12 biotite, B2:12 clinopyroxene, B2:10–11 iron-titanium oxide, B2:11–12 olivine, B2:10 orthopyroxene, B2:11 plagioclase, B2:10
modal layering petrology, A4:36–37 photograph, A4:100
modal variations gabbro, B(synthesis):9–11, 67, 105–107; B2:28 vs. depth, B(synthesis):67
Mohorovicic discontinuity, gabbroic rocks, A4:7–8
mylonite crystal-plastic deformation, A4:53–54; B(synthesis):43–44 photograph, A4:139–140 photomicrograph, A4:141–143, 145
mylonite, porphyroclastic, crystal-plastic deformation, A4:53–54

N

neoblasts crystal-plastic deformation, A4:53–54 lithology, A2:5 photomicrograph, A4:132, 137, 141, 143, 145; B2:27 porphyroclastic textures, A4:53 textures, B(synthesis):41
NERO site drilling, A1:9–11; A4:66–67 site description, A5:1–28
nickel gabbroic rocks, A4:45–47; B(synthesis):17 mineral chemistry, B2:10 vs. depth, A4:125
nickel, whole-rock, vs. whole-rock magnesium number, B(synthesis):78
nickel oxide vs. depth in olivine, B(synthesis):93 vs. forsterite, B(synthesis):83 vs. magnesium number in clinopyroxene, B(synthesis):93
Ninetyeast Ridge drilling, A1:1–26 free-air gravity maps, A5:19
Ninetyeast Ridge Observatory, drilling, A1:1–26
niobium gabbro, A2:5 gabbroic rocks, A4:45–47 vs. depth, A4:124
nuclear logs, gabbroic rocks, A4:63–64

O

obduction, seafloor spreading, A4:11–13
olivine composition, B2:53–55 cumulates, B2:52 gabbroic rocks, A4:30–42; B(synthesis):8–11, 22 lithologic units, A4:31–34 lithology, A2:5 magnesium number and forsterite, B(synthesis):91 major elements, B(synthesis):120–122; B2:66–68 mineral chemistry, B2:10, 13–14 ophiolite, A4:13 petrography, A4:38–41; B(synthesis):40–47; B2:6–9, 14–21 photomicrograph, A4:108, 138; B2:27, 29, 34 vs. depth, A4:94–96; B2:26, 47–48 See also clinopyroxene-olivine-opaque minerals; clinopyroxene-olivine-plagioclase; forsterite
olivine aggregate, photomicrograph, A4:112
olivine gabbro crystal-plastic deformation, A4:54 geochemistry, A4:8–9 lithologic units, A4:31–34 lithology, A2:4–6 petrography, A4:38–41; B2:7–8 petrology, A4:30–42; B(synthesis):8
olivine gabbro, coarse-grained, photomicrograph, A4:111
olivine gabbro, fine-grained, photomicrograph, A1:20, 24; A4:99, 105, 108, 116
olivine gabbro, medium-grained, photomicrograph, A1:19–20, 23; A4:105, 112–113
opaque minerals photomicrograph, A4:117, 141, 145 vs. depth, A4:94; B2:26, 45 See also clinopyroxene-olivine-opaque minerals
ophiolite seafloor spreading, A4:11–13 stratigraphy, A4:11–13, 48 typical stratigraphy, A4:79
orthoclase mineral chemistry, B2:10 vs. anorthite, B2:35
orthocumulate gabbroic rocks, B(synthesis):18 lithology, A2:5–6
orthopyroxene composition, B2:53–55 gabbroic rocks, A4:30–42; B(synthesis):8, 26 lithologic units, A4:31–34; B(synthesis):9–11 mineral chemistry, B2:11 petrography, A4:38–41 photomicrograph, A4:117–118; B2:33
oxidation, veins, A4:55
oxide gabbro composition, A4:9 crystal-plastic deformation, A4:54 lithologic units, A4:31–34 lithology, A2:4–6 modal layering, A4:36–37 orientation, B3:27–28 petrography, A4:38–41; B2:8 petrology, A4:30–42; B(synthesis):8, 34–37 photograph, B3:19 photomicrograph, A4:100, 118, 122, 137 structure, B3:9
oxide gabbro, coarse-grained, photograph, A4:104
oxide gabbro, foliated, photograph, A4:144
oxide gabbro, medium-grained, photomicrograph, A4:119
oxide gabbro, olivine-bearing, photomicrograph, A4:120
oxide gabbronorite, petrography, A4:38–41
oxide olivine gabbro lithologic units, A4:31–34 petrography, A4:38–41 petrology, A4:30–42
oxide olivine gabbro, fine-grained, photograph, A4:104
oxide-rich zone, correlation, B(synthesis):47
oxides, gabbroic rocks, B(synthesis):9–11, 33
oxides, modal, whole-rock, vs. whole-rock magnesium number, B(synthesis):70
oxygen fugacity, vs. temperature, B2:43

P

paleomagnetism, core, A4:9
partition coefficient, gabbroic rocks, B(synthesis):15
perfect fractional crystallization, gabbro, B(synthesis):13
petrography, gabbroic rocks, A4:38–41; B2:6–9
petrology, gabbro, B2:1–76
phosphorus oxide gabbro, A2:5; B2:17 gabbroic rocks, A4:45–47; B(synthesis):14 oxide gabbro, A4:41 vs. depth, A4:123; B2:45 vs. magnesium number, B2:50
photoelectric effect logs gabbroic rocks, A4:63–64 vs. depth, A4:156
physical properties, Site 1105, A4:57–60
pigeonite, gabbro, A4:41; B(synthesis):9–11, 26
plagioclase composition, B2:53–55 cumulates, A4:42; B2:52 hydrothermal alteration, A4:43–44; B(synthesis):8 lithologic units, A4:31–34; B(synthesis):9–11, 27 magnesium number and anorthite, B(synthesis):91 major elements, B(synthesis):123–125; B2:56–60 mineral chemistry, B2:10, 13–14 petrography, A4:38–41; B(synthesis):40–45; B2:6–9, 16–21 photograph, A4:139–140 photomicrograph, A4:115, 132–133, 138, 141–142, 145 porphyroclastic textures, A4:53 twinning, A4:50–51 veins, A4:55 vs. depth, A4:94–96; B2:26, 47–48 See also albite; anorthite; clinopyroxene–olivine–plagioclase
plagioclase, anhedral, photomicrograph, A1:23
plagioclase, strained, photomicrograph, A1:24
plagioclase, subhedral photograph, A4:126 photomicrograph, A4:109, 129
plagioclase, tabular, photomicrograph, A4:127
plagioclase, zoned, photomicrograph, A4:116
plagioclase laths photograph, A4:126 photomicrograph, A4:110 textures, B(synthesis):40
planar contacts, petrology, A4:34–35; B3:18
porosity logs gabbroic rocks, A4:63–64 vs. depth, A4:156; B1:16-17
porphyroclasts, textures, B(synthesis):40–43
potassium logs, vs. depth, A4:155
potassium oxide gabbroic rocks, A4:45–47 vs. anorthite in plagioclase, B(synthesis):89
preferred orientation gabbroic rocks, A4:50–53 oxide-bearing lithology, B3:21–22, 27–28 photomicrograph, A4:127–128, 133 textures, B(synthesis):42
prehnite, amphibolite gneiss, A4:9
primocrysts, planar fabric, A4:35
pseudomorphs, petrology, A4:44
pseudostratigraphy, magnetic susceptibility, B(synthesis):7–11
pyroxene major elements, B2:61–65 quadrilateral components, B2:37 quadrilateral plot, B(synthesis):86 twinning, A4:51 vs. depth, A4:94–96; B2:26 See also augite; clinopyroxene; ferrosilite; hedenbergite

R

rare earths comparison of plutonics of Site 1105 and basalts of Atlantis II Fracture Zone, B(synthesis):80 gabbroic rocks, B(synthesis):15–19, 72–77, 114–116
recrystallization gneissic textures, A4:52 hydrothermal alteration, A4:42–44 lithology, A2:5 photograph, A4:139–140 photomicrograph, A4:132–133, 137–138
remanent magnetization, natural, gabbroic rocks, A4:59
resistivity, gabbroic rocks, A4:62–63; B3:8–29
resistivity logs, vs. depth, A4:155; B3:25–26
Riedel shears, photomicrograph, A4:141
rift valleys gabbro, B2:3–4 tectonics, B(synthesis):5–7 transform faults, A4:6–8
Rodriguez Triple Junction, tectonics, B(synthesis):4
rotation, gabbroic rocks, A4:56
rubidium, gabbroic rocks, A4:45–47

S

seafloor spreading rift valleys, A4:6–8 tectonics, B(synthesis):5–7
seismic profiles, location, A5:23, 28
seismic studies experiments, A5:10–12 gabbroic rocks, A4:65–67, 160–164 spectra, A5:22
seismic while drilling Site 1105, A4:65–67 Site 1107, A5:10–12
seismicity, intraplate, Indian Ocean, A5:18
serpentine, hydrothermal alteration, A4:43–44; B(synthesis):8
shear zones gabbroic rocks, A4:56; B(synthesis):35 layer contacts, A4:51 magnetic susceptibility, A2:6 photograph, A4:130, 144 photomicrograph, A4:143 tectonics, B(synthesis):6
silica gabbroic rocks, A4:45–47; B(synthesis):9, 14 vs. iron oxide, B2:50
silica, whole-rock vs. whole-rock iron oxide, B(synthesis):70 vs. whole-rock magnesium number, B(synthesis):70
silicates, composition, B2:53–55
Site 735 correlation of oxide-rich zone with Site 1105, B(synthesis):47 gabbro cumulates, B2:52 gabbroic rocks, A4:8–9
Site 757, drilling, A1:9
Site 1104, A2:2–3 drilling, A1:5–6; A4:19–23 hammer drill site, A4:1–183 principal results, A2:2–3 site description, A2:2–3
Site 1105, A2:3–6; A4:1–183 acceleration, B1:5–6 alteration, A4:42–48 core-log correlation, B3:1–29 coring summary, A2:12 correlation of oxide-rich zone with Site 735, B(synthesis):47 downhole logging, A4:60–65 drilling, A1:7–9; A4:23–24 gabbro, B2:1–76 geochemistry, A4:45–48 igneous petrology, A4:29–42 lithology summary, A1:16 lithostratigraphy, A2:11; A4:30–34; B(synthesis):7–11 magnetic susceptibility, B(synthesis):7–11 metamorphic petrology, A4:42–48 operations, A4:14–29, 183 physical properties, A4:57–60 principal results, A2:3–6 seismic while drilling, A4:65–67 site description, A2:3–6; A4:1–183 structural geology, A4:48–57
Site 1106, A2:6–8 drilling, A1:6–7; A4:24–27 hammer drill site, A4:1–183 principal results, A2:6–8 site description, A2:6–8
Site 1107, A2:8–10; A5:1–28 acceleration, B1:6 background, A5:2–3 drilling, A1:9–11 NERO site, A5:1–28 operations, A5:7–10 principal results, A2:8–10 scientific objectives, A5:3–6 seismic while drilling, A5:10–12 site description, A2:8–10; A5:1–28 site selection and characteristics, A5:6–7
Skaergaard intrusion, gabbro cumulates, B2:52
slow-spreading centers, rift valleys, A4:6–8
smectite amphibolite gneiss, A4:9 hydrothermal alteration, A4:43–44; B(synthesis):8 photograph, A4:147–149
sodium mineral chemistry, B2:10–12 vs. magnesium number, B2:38
sodium oxide, vs. magnesium number in clinopyroxene, B(synthesis):85
sonic logs, gabbroic rocks, A4:64
Southwest Indian Ridge core-log correlation, B3:1–29 drilling, A1:1–26; A4:1–14, 17–29 free-air gravity maps, A4:73 synthesis, B(synthesis):1–125 tectonics, A4:6–8
spectra seismic studies, A5:22 vs. depth, B1:15 sphene. See titanite
spinel, ophiolite, A4:13
strain photomicrograph, A4:133, 144 veins, A4:55
strain localization, crystal-plastic deformation, A4:53–54
stratigraphy ophiolite, A4:11–13 synthesis, B(synthesis):1–125
strontium, gabbroic rocks, A4:45–47; B(synthesis):15
structural geology, Site 1105, A4:48–57
structure gabbroic rocks, A4:48–50; B(synthesis):34–35 magnetic field, A4:56 synthesis, B(synthesis):1–125
structure, brittle gabbroic rocks, A4:9, 54–56 massifs, A4:56–57
structure, crystal-plastic, gabbroic rocks, A4:9, 47–48
structure, ductile, massifs, A4:56–57
sulfides lithologic units, A4:31 petrography, A4:38–41 photomicrograph, A4:118
symplectic intergrowth, photomicrograph, A4:115

T

talc, hydrothermal alteration, A4:43–44; B(synthesis):8
tectonic contacts, petrology, A4:34–35
tectonic windows seafloor spreading, A4:11–13 tectonics, B(synthesis):7
tectonics gabbro, B2:3–4 geology, B(synthesis):4–7 rift valleys, A4:6–8
temperature gabbroic rocks, A4:64–65 vs. oxygen fugacity, B2:43
textures gabbroic rocks, A4:30–34, 50–53; B(synthesis):36–44 gain-size layering, A4:37 lithologic units, A4:31–34 lithology, A2:5
textures, coarse-grained, gabbroic rocks, A4:50–53
textures, cumulate lithology, A2:5–6 photomicrograph, B(synthesis):65
textures, fine-grained, gabbroic rocks, A4:50–53
textures, granular lithologic units, A4:31 petrography, A4:39–41 photomicrograph, A1:20
textures, magmatic-tectonite, deformation, A4:51–52
textures, medium-grained, gabbroic rocks, A4:50–53
textures, metamorphic, lithology, A2:5
textures, moderately recrystallized gabbroic rocks, B(synthesis):38–47 photomicrograph, B(synthesis):97
textures, moderately recrystallized to porphyroclastic gabbroic rocks, B(synthesis):40–41 photomicrograph, B(synthesis):98
textures, mylonitic gabbroic rocks, A4:30–34; B(synthesis):43–44 hydrothermal alteration, A4:42–44 photomicrograph, B(synthesis):101
textures, oikocryst lithology, A2:5 petrography, A4:39 photomicrograph, A4:109–110, 129
textures, poikilitic hydrothermal alteration, A4:42–44 photomicrograph, B2:29
textures, porphyroclastic gabbroic rocks, B(synthesis):41–42 hydrothermal alteration, A4:42–44 lithology, A2:5; A4:47 photograph, A4:134–136, 139–140 photomicrograph, A4:137–138, 141, 143, 145; B(synthesis):99; B2:27
textures, porphyroclastic to mylonitic gabbroic rocks, A4:30–34; B(synthesis):42–43 photomicrograph, B(synthesis):100
textures, porphyroclastics, recrystallization, A4:52–53
textures, ultramylonitic gabbroic rocks, A4:30–34; B(synthesis):44 photomicrograph, B(synthesis):101
textures, undeformed gabbroic rocks, B(synthesis):37 photomicrograph, B(synthesis):95
textures, weakly recrystallized gabbroic rocks, B(synthesis):37–38 photomicrograph, B(synthesis):96
thermal structures, axial, slow-spreading centers, A4:10
thorium logs, vs. depth, A4:155
titanite petrography, A4:40–41 photomicrograph, A4:119
titanium mineral chemistry, B(synthesis):15; B2:10–12 phase equilibria, B2:41 vs. aluminum, B2:39 vs. magnesium number, B2:38 vs. tetrahedral aluminum in clinopyroxene, B(synthesis):87
titanium/aluminum ratio, vs. magnesium number, B2:39
titanium oxide gabbroic rocks, A4:45–47; B(synthesis):9, 13–14, 25, 32; B2:12–20 vs. depth, A4:123; B(synthesis):81; B2:45 vs. magnesium number in clinopyroxene, B(synthesis):85 vs. magnesium number in melt, B(synthesis):94 vs. tetrahedral aluminum in clinopyroxene, B(synthesis):88 See also iron-titanium oxide
titanium oxide, whole-rock vs. whole-rock iron oxide, B(synthesis):70 vs. whole-rock magnesium number, B(synthesis):70–71 vs. whole-rock magnesium oxide, B(synthesis):70
titanomagnetite composition, B(synthesis):26 major elements, B2:69–73 oxygen fugacity, B2:43 phase equilibria, B2:41 photomicrograph, B2:33
trace elements, gabbroic rocks, A4:45–47, 179–182; B(synthesis):15–17, 111–113
transform valleys median ridges, A4:7 tectonics, B(synthesis):5
transverse ridges tectonics, B(synthesis):6 transform valleys, A4:7
traveltime, vs. depth, A5:24–27
trondhjemite lithology, A2:4–6 veins, A4:55
twinning photomicrograph, A4:127–128 plagioclase, A4:50–51 pyroxene, A4:51

U

ultramylonite, crystal-plastic deformation, A4:53–54; B(synthesis):44–45
undulose extinction, lithology, A2:5
unroofing detachment faults, A4:7 massifs, A4:56 schematic model, A4:150
uplifts, gabbro, B2:3–4
uranium logs, vs. depth, A4:155

V

vanadium gabbroic rocks, A4:45–47 vs. depth, A4:124
veins, alteration, A2:5
veins, felsic lithologic units, A4:31–34; B(synthesis):63 petrography, A4:38–41 petrology, A4:30–42 photograph, A4:106, 144 structure, B(synthesis):7 vs. depth, A4:97
veins, leucocratic gabbro, photograph, A4:146
veins, magmatic brittle structures, A4:54–56 petrology, A4:37
veins, smectite-clay, photograph, A4:147–149
velocity, gabbroic rocks, A4:59–60
velocity logs, vs. depth, A4:156; B1:16
vibration, drilling, B1:1–17

W

well-logging gabbroic rocks, A4:60–65 orientation, B3:21–22 See also core-log correlation

Y

ytterbium vs. cerium, B(synthesis):79 vs. cerium/ytterbium ratio, B(synthesis):79 See also cerium/ytterbium ratio
yttrium gabbro, A2:5 gabbroic rocks, A4:45–47; B(synthesis):9 vs. depth, A4:124

Z

zeolite, amphibolite gneiss, A4:9
zinc, vs. depth, A4:124
zirconium gabbroic rocks, A4:45–47; B(synthesis):9 vs. depth, A4:124; B(synthesis):81
zoning, photomicrograph, B2:29