Ophiolites in earth history

Contents......Page 6
Preface......Page 8
Ophiolites in Earth history: introduction......Page 10
Ophiolite pulses, mantle plumes and orogeny......Page 18
Fig. 1. Global distribution of Proterozoic and Phanerozoic ophiolite belts and modern .........Page 20
Fig. 2. Histogram showing the occurrence of major ophiolites and ophiolite pulses .........Page 23
Arc–trench rollback and forearc accretion: 1. A collision-induced mantle flow model for Tethyan ophiolitesh......Page 30
Fig. 1. Plots of TiO[sub(2)] vs. FeO* (in wt%) for eruptive and intrusive lithologies .........Page 31
Fig. 2. MORB-normalized incompatible element distributions for eruptive lithologies sampled from typical .........Page 32
Fig. 3. Plate boundary evolution and arc–trench rollback in active Tethyan domains. .........Page 33
Fig. 4. Arc–trench rollback model, from Bloomer et al. (1995), based on .........Page 36
Fig. 5. Partial melting models for (a) fertile and (b) refractory peridotite .........Page 37
Fig. 6. Interpolated P–T–t histories for sub-ophiolitic metamorphic soles and other metamorphic .........Page 38
Fig. 7. Hypothetical effects of \'slab pull\' and \'mantle extrusion\', (a) Slab .........Page 39
Fig. 8. Mantle-driven Tethyan \'sub-cycle\' during late (pre-collision) stages of a Wilson .........Page 42
Arc–trench rollback and forearc accretion: 2. A model template for ophiolites in Albania, Cyprus, and Oman......Page 52
Fig. 1. (a) Distribution of major Neo-Tethyan ophiolites and suture zones in .........Page 53
Fig. 1. (b) Distribution of the Neo-Tethyan ophiolites and major tectonic features .........Page 54
Fig. 2. (a) Distribution of Neo-Tethyan ophiolites in the Balkan Peninsula. The .........Page 60
Fig. 3. (a) Simplified geological map of Cyprus showing the Troodos ophiolite, .........Page 63
Fig. 4. (a) Distribution of the Neo-Tethyan ophiolites and the location of the .........Page 65
Fig. 5. Generalized tectonic diagrams depicting late-stage (prior to trench–passive margin collision .........Page 69
Melt migration in ophiolitic peridotites: the message from Alpine–Apennine peridotites and implications for embryonic ocean basins......Page 78
Fig. 1. Generalized tectonic overview of the Alpine and Northern Apennine ophiolites. .........Page 80
Fig. 2. Generalized structural and stratigraphic relationships of an ancient ocean–continent transition .........Page 81
Fig. 3. Field aspects of plagioclase peridotites and dunites from Lanzo South .........Page 83
Fig. 4. Field aspects of plagioclase peridotite and gabbronorite from the Monte .........Page 85
Fig. 5. Selected thin section specimens from the Lanzo South area. (a) Intergrowth .........Page 86
Fig. 7. Representative REE concentrations in minerals from (a) gabbroic cumulates of .........Page 90
Fig. 8. Generalized evolution of subcontinental peridotites from embryonic ocean basins above .........Page 91
Fig. 9. Possible scenario of mantle exhumation and melt–rock reaction in the .........Page 93
Table 1. Representative analyses of minerals from Lanzo South and Monte Maggiore peridotites......Page 88
Table 2. Representative analyses of minerals from Lanzo South replacive dunite, gabbro veinlets and Monte gabbronorite cumulates .........Page 89
Petrology and evolution of the Brezovica ultramafic massif, Serbia......Page 100
Fig. 1. Location of the Brezovica ultramafic massif (modified after Karamata & Krstic 1996). .........Page 101
Fig. 2. Geological map and cross-section of the Brezovica area with sites of rock sampling.......Page 102
Table 3. Pyroxene compositions......Page 105
Table 4. Compositions of other minerals......Page 106
Fig. 8. Variations of bulk-rock FeO/SiO[sub(2)] ratios for Brezovica ultramafic rocks. Symbols .........Page 108
Fig. 9. Variations of chondrite-normalized bulk-rock Ti/A1 ratios with Cr number of spinels. .........Page 109
Fig. 10. An example of the calculated distribution of closure temperatures of .........Page 110
Table 2. Olivine compositions......Page 104
Table 5. Bulk-rock compositions......Page 107
Triassic mid-ocean ridge basalts from the Argolis Peninsula (Greece): new constraints for the early oceanization phases of the Neo-Tethyan Pindos basin......Page 118
Fig. 1. Structural zones of the Albanide–Hellenide Alpine orogenic belt (modified after .........Page 120
Fig. 2. Simplified geological maps showing the main outcrops of the Middle .........Page 121
Fig. 3. Geological cross-sections of the northern and central Argolis Peninsula. No .........Page 123
Fig. 4. Measured logs of the sampled sections, showing the stratigraphic relationships .........Page 124
Fig. 5. N-MORB-normalized incompatible element abundance patterns and chondrite-normalized REE abundance patterns .........Page 128
Fig. 8. Zr/4–Y–2 X Nb discrimination diagram for the Triassic basaltic rocks from .........Page 129
Fig. 10. Th/Ta v. Th/Tb diagrams for Triassic basaltic rocks from the Middle .........Page 130
Fig. 11. Ti v. Zr diagram for Triassic basaltic rocks from the Middle Unit .........Page 131
Fig. 12. Schematic evolution of the early oceanization phases of the Pindos .........Page 133
Table 1. Bulk-rock major and trace element analyses of Triassic basaltic rocks .........Page 125
Structural and microstructural analysis of a palaeo-transform fault zone in the Neyriz ophiolite, Iran......Page 138
Fig. 1. Geological map of the Neyriz area showing the distribution of .........Page 140
Fig. 2. Geological map of the Neyriz ophiolite with its oceanic palaeo-transform .........Page 141
Fig. 3. Equal-area, lower-hemisphere projection of the measured sheeted dyke orientations. .........Page 142
Fig. 4. (a) Cross- and plane-polarized light photomicrographs of a mylonite composed of .........Page 146
Fig. 5. (a, b) Hornblende c-axis and a-axis pole figures. Equal-area, lower-hemisphere .........Page 148
Fig. 6. Tracing of the XZ section of the sample from the .........Page 150
Fig. 7. Kinematic model of the Neyriz ridge–transform intersection modelled according to .........Page 152
Fig. 8. Schematic diagram of the interpretative dextral transform fault in the .........Page 153
Table 1. Microprobe analyses and structural formulae of amphiboles of the mylonite......Page 144
Stratigraphic and sedimentological constraints on the age and tectonic evolution of the Neotethyan ophiolites along the Yarlung Tsangpo suture Zone, Tibet......Page 156
Fig. 1. Geological sketch map of the Yarlung Tsangpo suture zone across .........Page 157
Fig. 2. (a) Geological map of the Xigaze–Renbung area (modified after Wang .........Page 159
Fig. 3. Summary time–space plot for terranes and tectonically significant units recognized .........Page 160
Fig. 4. (a) Ophiolitic rocks exposed at Dangxiong near the headwaters of the .........Page 164
Fig. 5. Some representative mid-Cretaceous (lowermost upper Aptian UA8) radiolarians from siliceous .........Page 166
Fig. 6. Radiolarian-based ages of supra-ophiolitic sedimentary sections associated with the Dazhuqu .........Page 167
Table 1. Summary of key characteristics of various ophiolitic rocks along the Yarlung Tsangpo suture zone......Page 158
Yarlung Zangbo ophiolites (Southern Tibet) revisited: geodynamic implications from the mineral record......Page 174
Fig. 1. Location map of the Yarlung Zangbo ophiolite massifs. (a) Western .........Page 175
Fig. 2. Geological maps of the studied ophiolite massifs showing sample locations. .........Page 178
Fig. 3. Idealized cross-sections of the Beimarang and Dazhuqu massifs showing similarities .........Page 179
Fig. 4. Compositional variations of spinels from peridotites and mafic plutonic rocks. .........Page 186
Fig. 5. Microphotographs of different textures in peridotites and mafic plutonic rocks. .........Page 187
Fig. 6. Variations of NiO v. Mg number in olivines from peridotites .........Page 188
Fig. 7. Compositional variations of orthopyroxenes from peridotites and mafic plutonic rocks. .........Page 189
Fig. 8. Compositional variations of clinopyroxenes from peridotites and mafic plutonic rocks. .........Page 192
Fig. 9. Compositional variations of clinopyroxenes and orthopyroxenes from ultramafic and mafic .........Page 193
Fig. 10. Polybaric origin of Yarlung Zangbo ophiolitic massifs as deduced from .........Page 195
Fig. 11. Simplified geodynamic model for the evolution of the Yarlung Zangbo suture zone ophiolites.......Page 196
Table 1. Summarized petrography of the Yarlung Zangbo Suture Zone ophiolite samples......Page 181
Geochemical and geochronological constraints on the origin and emplacement of the Yarlung Zangbo ophiolites, Southern Tibet......Page 200
Fig. 1. Geological map of the Indus-Yarlung Zangbo suture zone, southern Tibet, .........Page 201
Table 1. Major terranes of the Indus-Yarlung Zangbo Suture showing their rock .........Page 202
Fig. 3. Geological map of the area immediately west of Zedong (after McDermid et al. 2002).......Page 204
Fig. 6. (a, b) Chondrite-normalized REE distribution patterns of basaltic rocks from the .........Page 207
Fig. 7. Spider diagrams of MORB-normalized trace element abundances in basaltic rocks .........Page 208
Fig. 8. SHRIMP U–Pb zircon concordia plot for sample D13, a quartz diorite from the Dazhuqu massif.......Page 210
Fig. 9. Ar/Ar spectra of amphibole and biotite from rocks of the .........Page 211
Fig. 10. Schematic diagram of the plate tectonic evolution of the Neo-Tethyan .........Page 212
Table 2. Major oxides (wt.%) and trace elemental abundances (ppm) of rocks from the Indus–Yarlung Zangbo Suture Zone......Page 206
Table 3. SHRIMP zircon analytical results for zircons from quartz diorite D13, from Dazhuqu massif, southern Tibet (uncertainties are 1σ)......Page 209
Tectonic implications of boninite, arc tholeiite, and MORB magma types in the Josephine Ophiolite, California–Oregon......Page 216
Fig. 1. Middle Jurassic Ophiolites of the western USA that are similar .........Page 217
Fig. 2. Generalized geological map of the west–central Klamath Mountains (Snoke 1977; .........Page 218
Fig. 3. MgO variation diagrams for low-Ti dykes (omitted) and pillow lavas (omitted) .........Page 224
Fig. 4. Ti v. V discriminant diagram (Shervais 1982). IAT, island-arc tholeiite; MORB, .........Page 225
Fig. 5. Y v. Cr discriminant diagram (Pearce 1982). (See Fig. 4 for key .........Page 226
Fig. 6. Low-Ti dykes (omitted) and pillow lavas and breccias (omitted) plotted in .........Page 227
Fig. 7. Th/Yb v. Ta/Yb diagram from Pearce (1982). (See Fig. 4 for .........Page 228
Fig. 8. TiO[sub(2)] v. La/Sm diagram (Meffre et al. 1996) showing fields for .........Page 229
Fig. 9. REE- and MORB-normalized diagrams for selected dykes and lavas from .........Page 230
Fig. 10. (a) Mineral chemistry of Cr-spinel in low-Ti dykes and lavas .........Page 231
Table 1. Major (%) and trace element (ppm) analyses for low-Ti dykes and lavas......Page 220
Table 2. Selected chemical analyses of pillow lavas, sheeted dykes, and plagiogranites......Page 222
Table 3. Selected analyses of Cr-spinel from low-Ti dykes and lavas......Page 223
Forearc extension and sea-floor spreading in the Thetford Mines Ophiolite Complex......Page 240
Fig. 1. Geological and structural map of the Thetford Mines Ophiolitic Complex, .........Page 242
Fig. 2. Stratigraphic columns. Column C1, Thetford Mines Massif (TMM), Caribou Lake. .........Page 243
Fig. 3. Geological map of part of the Adstock–Ham Massif, with equal area .........Page 245
Fig. 4. Photographs and sketches illustrating syn-oceanic deformation features from the lower .........Page 246
Fig. 5. Sketches illustrating syn-oceanic deformation features from the lower crust in .........Page 247
Fig. 6. Photographs and sketches illustrating syn-oceanic deformation features from the upper .........Page 249
Fig. 7. (a) Interpretative palaeogeographical reconstruction of the Thetford Mines Ophiolitic Complex .........Page 253
Fig. 8. Schematic illustrations of a possible evolutionary scenario for the main, .........Page 254
Fig. 9. (a) Schematic illustrations of a possible configuration for the genesis .........Page 255
Cr-spinel compositions, metadunite petrology, and the petrotectonic history of Blue Ridge ophiolites, Southern Appalachian Orogen, USA......Page 262
Fig. 1. Map of the Blue Ridge Belt showing major faults, thrust .........Page 263
Fig. 2. Maps and sections of selected meta-ultramafic rock bodies of the .........Page 264
Fig. 3. Photomicrographs and a photograph of meta-ultramafic rocks. (a) Photomicrograph of .........Page 268
Fig. 4. Petrogenetic grid showing fields of contact metamorphism (C), greenschist facies .........Page 269
Fig. 5. Graph showing distribution of anhydrous (A), partially hydrated (M), and .........Page 271
Fig. 6. Graphs showing the relationships between aspect ratio (long/short dimension) and long .........Page 273
Fig. 8. Schematic diagram showing relationship between peridotite mantle rock, dunite alteration .........Page 278
Fig. 10. TiO[sub(2)]–Al[sub(2)]O[sub(3)] diagram showing the compositions of selected Hess Deep (open .........Page 279
Fig. 11. Backscatter image of chromium spinel from Frank ultramafic body showing .........Page 280
Table 1. Metamorphic associations in Blue Ridge meta-ultramafic rocks......Page 265
Table 2. Electron microprobe analyses of Cr-chlorites and Cr-spinels from Blue Ridge meta-ultramafic rocks......Page 266
Table 3. Characteristic features of typical Blue Ridge ultramafic bodies and rock types......Page 267
Table 4. Selected whole-rock chemistries of Blue Ridge ultramafic bodies......Page 270
Table 5. Chemical data from anhydrous to hydrated Blue Ridge meta-ultramafic rocks......Page 272
Table 6. Aspect ratios of North Carolina Blue Ridge ultramafic bodies......Page 274
Table 7. Chemistries of coexisting olivine and chrome-spinels......Page 275
Table 8. Electron microprobe analyses of representative spinels from Hess Deep and Blue Ridge ultramafic rocks......Page 277
Multi-stage evolution of the Tertiary Mineoka ophiolite, Japan: new geochemical and age constraints......Page 288
Fig. 2. Index map of the Mineoka Belt after Hirano & Okuzawa (2002).......Page 289
Fig. 3. Outcrop photographs: (a) tholeiite pillow basalt; (b) dolerite sheeted dyke .........Page 290
Fig. 4. (a) SiO[sub(2)]–total alkali diagram. Nomenclature of volcanic rocks is after .........Page 293
Table 2. K–Ar age results......Page 294
Fig. 6. Ar/Ar age results. [sup(39)]Ar/[sup(40)]Ar–[sup(36)]Ar/[sup(40)]Ar isochrons and age spectra of sample .........Page 296
Fig. 7. Plate tectonic reconstruction of the Philippine Sea Plate before 43 .........Page 297
Fig. 8. Formation ages of the ocean basin and arcs shown on .........Page 298
Fig. 9. Tectonic reconstruction models for the origin of the Mineoka ophiolitic .........Page 299
Fig. A1. Index map of the sample localities shown in Figures A2–A5, .........Page 303
Fig. A2. Sample locality map around the Kamogawa area. BM09BT1, dolerite; BM23BT2, .........Page 304
Fig. A3. Sample locality map around the Mineoka Sengen area along the .........Page 305
Fig. A4. Sample locality map around the Hegurinaka area in the central .........Page 306
Fig. A5. Sample locality map around the Sakuma area in the western .........Page 307
Table 1. Geochemical compositions of bulk-rock samples......Page 291
Table 3. Ar/Ar age results......Page 295
The nature of faulting and deformation in the Mineoka ophiolite, NW Pacific Rim......Page 308
Fig. 1. Index map of the Mineoka Belt and its surroundings (adapted .........Page 309
Fig. 2. General lithological map and cross-section of the study area around .........Page 310
Fig. 4. Outcrop photograph showing deformation of inter-pillow calcite (Cal) and intra-pillow .........Page 311
Table 1. Phases and stages of faulting, veining and other events in basaltic rock bodies of the Mineoka Belt......Page 312
Fig. 6. (a) Polished surface of a hand sample showing first-stage faults; .........Page 313
Fig. 7. (a) Mutual cross-cutting relationship of the second-stage faults in thin .........Page 314
Fig. 9. Photomicrograph showing analcime (Anl) vein crosscutting the sheared, pulverized fault zone rock.......Page 315
Fig. 11. (a) Interpretive sketch, and (b) and (c) outcrop photographs of .........Page 316
Fig. 13. Photomicrograph of a third-stage fault, showing first analcime (Anl1), second .........Page 317
Fig. 14. Stereographic projections of second-stage faults at Shinyashiki. (a) Kamb contour .........Page 318
Fig. 16. Stereographic projection of faults in dolerite dyke swarms, Benten Island.......Page 319
Fig. 18. Outcrop sketch and an areal photograph of the \'Aranami Fault\', .........Page 320
Fig. 19. Schematic diagram of deformation of the \'Aranami Fault\', Benten Island.......Page 321
Fig. 20. Riedel shears on various scales from (a) outcrop size to .........Page 322
Oxygen isotope and chemical studies on the origin of large plagiogranite bodies in northern Oman, and their relationship to the overlying massive sulphide deposits......Page 324
Fig. 1. Regional geological map of the northern half of the Semail .........Page 325
Fig. 2. Simplified geological map of the Lasail–Assayab area (modified after Lippard (1980); .........Page 328
Fig. 3. Simplified geological map of the Aarja–Bayda area showing sample localities .........Page 329
Fig. 4. Simplified geological map of the Suhaylah area (modified after Lippard .........Page 334
Fig. 5. Schematic diagram of the stratigraphic zone in the Semail ophiolite .........Page 338
Fig. 6. (a) Photograph (hammer in lower right for scale) of relationships .........Page 341
Fig. 7. Schematic diagram of outcrop relationships in Assayab prospect area (See .........Page 344
Fig. 8. Plot of δ[sup(18)]O v. relative structural height in the ophiolite for .........Page 345
Fig. 9. Plot of δ[sup(18)]O of whole-rock and mineral samples in the .........Page 347
Fig. 10. Composite plot of δ[sup(18)]O for minerals and whole rocks from .........Page 348
Fig. 11. Plagioclase δ[sup(18)]O v. quartz δ[sup(18)]O for mineral separates from plagiogranites in northern .........Page 349
Fig. 12. (a) Zr/Y v. Mg number for all dykes and gabbros. (See Table 5 .........Page 350
Fig. 13. (a) REE patterns for 13 plagiogranites having SiO[sub(2)] >63.5 wt.%, and .........Page 352
Fig. 14. Modification of Figure 1 of Spera & Bohrson (2001) with field parameters .........Page 354
Fig. 15. Schematic depiction of the structural relationships between a plagiogranite body .........Page 355
Fig. 16. Proposed crustal model of the complex multiple magmatic systems for .........Page 357
Table 1. Oxygen isotopic and petrogmphic data for samples collected from map .........Page 330
Table 2. Oxygen isotopic and petrographic data for samples collected from map .........Page 332
Table 3. Oxygen isotopic and petrographic data for samples collected from map .........Page 333
Table 4. Geochemistry of samples from northern Oman......Page 335
Table 5. Plagiogranites (with silica content given in parentheses)......Page 337
Ophiolites and global geochemical cycles: implications for the isotopic evolution of seawater......Page 362
Fig. 1. Isotopic profiles through the Samail ophiolite modified after McCulloch et al. .........Page 364
Fig. 2. Comparison between the oceanic layer 3 gabbro results (Stakes 1991; .........Page 366
Fig. 3. Comparison of Skaergaard intrusion mineral pair data with those from .........Page 368
Fig. 4. δ[sup(18)]O values of greenstones through geological time. Greenstones with δ[sup(18)]O .........Page 369
Fig. 5. A comparison between the δ[sup(18)]O values of sandstones from an .........Page 371
Fig. 6. δ[sup(18)]O evolution of seawater for plausible choices of spreading rates .........Page 372
Table 2. Water balance......Page 373
Fig. 8. Schematic profile showing a δ[sup(18)]O profile typical for near steady-state conditions, .........Page 374
Table 1. Tectonic rates transformed into cycle rates, characteristic times, weighting factors .........Page 370
Hydrothermal circulation and metamorphism in crustal gabbroic rocks of the Bay of Islands ophiolite complex, Newfoundland, Canada: evidence from mineral and oxygen isotope geochemistry......Page 378
Fig. 1. Map of Bay of Islands ophiolitic complex modified from Casey et al. (1983, 1985).......Page 380
Fig. 2. Structural map of the gabbroic unit of North Arm Mountain .........Page 381
Fig. 3. Map of sampled site TB09.16. δ[sup(18)]O values (%o) are given .........Page 382
Fig. 4. (a) Site TA02.06 from structural Domain 4 showing a mylonite, .........Page 384
Fig. 5. Pyroxene compositions for structural Domains (a) 3 and (b) 4, .........Page 385
Fig. 6. Plagioclase compositions for structural Domains (a) 3 and (b) 4, .........Page 391
Fig. 7. Classification of amphiboles for structural Domains (a) 3 and (b) 4 .........Page 393
Fig. 9. A1IV v. (Na + K)A for amphiboles of structural Domains (a) 3 and (b) .........Page 395
Fig. 10. Histograms of oxygen isotope compositions for whole rock for structural Domains 3 and 4.......Page 399
Fig. 11. (a) An v. δ[sup(18)]O values for plagioclases, and (b) A1IV v. δ[sup(18)]O values .........Page 400
Fig. 12. (a) δ[sup(18)]O values of plagioclase (+), amphibole (omitted) and whole .........Page 401
Fig. 13. δ[sup(18)]Oplagioclase v. δ[sup(18)]Oclinopyroxene (filled symbol) or δ[sup(18)]Oamphibole (open symbol) for .........Page 403
Fig. 14. Evolution of hydrothermal circulation, (a) In structural Domain 3, seawater .........Page 405
Table 1. Synthesis of petrography, mineralogy and isotope composition for plagioclase, amphibole, pyroxene, olivine and whole rock......Page 386
Table 2. Clinopyroxene compositions......Page 390
Table 3. Plagioclase compositions......Page 392
Table 4. Amphibole composition......Page 394
Table 5. Chlorite compositions......Page 396
Table 6. Prehnite and epidote compositions......Page 397
Table 7. Comparison of temperatures yielded by mineralogical and oxygene isotope geothermometers......Page 398
Table 8. Calculated fluid/rock ratios and δ[sup(18)]O fluid compositions......Page 402
Ophiolites as faithful records of the oxygen isotope ratio of ancient seawater: the Solund–Stavfjord Ophiolite Complex as a Late Ordovician example......Page 410
Fig. 1. (a) Location map, showing the occurrence of the Solund–Stavfjord ophiolite .........Page 413
Table 2. Oxygen isotopic composition of rocks from the Strand profile of the SSOC......Page 417
Fig. 3. δ[sup(18)]O v. depth profile of rocks from the Strand section og Solund–Stavfjord .........Page 418
Fig. 5. δ[sup(18)]O of hydrothermal fluid v. depth in Solund–Stavfjord ophiolite. δ[sup(18)]O of .........Page 420
Table 1. Oxygen isotopic composition of rocks from Oldra profile of the SSOC......Page 416
Table 3. Measured isotopic ratios of epidosites from the SSOC and calculated .........Page 419
Bioalteration recorded in ophiolitic pillow lavas......Page 424
Fig. 1. Granular biogenerated textures: (a) from TOC; (b) from MOC. FG, fresh glass; GT, granular texture.......Page 427
Fig. 2. Tubular textures of bio-origin: (a) abundant thin tubes; (b) a .........Page 428
Fig. 4. Scanning electron microscope images showing organic-like remains (biofilm and filaments) .........Page 429
Fig. 5. Scanning electron microscope image and X-ray maps that show the .........Page 430
Fig. 6. Scanning electron microscope image and X-ray maps that show the .........Page 431
Fig. 7. Distribution of δ[sup(13)]C in glassy and crystalline pillow lavas from .........Page 432
Fig. 8. (a) Distribution of all δ[sup(13)]C data from the ophiolites as .........Page 433
What constitutes \'emplacement\' of an ophiolite?: Mechanisms and relationship to subduction initiation and formation of metamorphic soles......Page 436
Fig. 1. The preferred model of emplacing an ophiolite over a continental .........Page 437
Fig. 2. Illustration that ophiolite emplacement and the environment of the emplacement .........Page 438
Fig. 3. Model for inception of subduction. The width of the subophiolitic .........Page 442
Fig. 4. Emplacement of Tethyan and Cordilleran ophiolites (a) and ridge–trench ophiolites .........Page 445
Fig. 5. Tectonic history of the Coast Range ophiolite. The ophiolite is .........Page 448
Fig. 6. Comparing two representative P–T paths from the high-grade blocks of the .........Page 449
Ophiolite obduction and the Samail Ophiolite: the behaviour of the underlying margin......Page 458
Fig. 2. Thrust-stacking model of Tethyan-type obduction where the structurally highest unit .........Page 459
Fig. 4. Pre-thrusting reconstruction of the Oman margin showing restoration of the .........Page 460
Fig. 5. Maps of Saih Hatat. (a) Geological map of the Saih .........Page 461
Fig. 6. Landsat 5 image of NE Saih Hatat showing the Huwl-Meeh .........Page 462
Fig. 7. Profiles across the Saih Hatat domal culmination. Line of section .........Page 465
Fig. 8. The Saih Hatat fold–nappe, (a) Downplunge structural profile of the .........Page 466
Fig. 9. Saih Hatat fold–nappe schematic profile showing enlargement with the metamorphic .........Page 467
Fig. 10. Profiles across the Hawasina domal culmination. Line of section is B–B\' .........Page 468
Fig. 11. Speculative schematic illustrations of permissable tectonic scenarios allowing a mid-crustal .........Page 471
Subduction zone polarity in the Oman Mountains: implications for ophiolite emplacement......Page 476
Fig. 1. Geological map of the northern Oman Mountains.......Page 477
Fig. 2. Map of the Muscat–Quriat and Saih Hatat region, after LeMétour .........Page 478
Fig. 3. Model A, after Searle et al. (1994). Tectonic model for the .........Page 479
Fig. 4. Model B, after Gregory et al. (1998) and Gray et al. .........Page 480
Fig. 5. Geological cross-sections across the Hawasina Window, after Searle and Cooper .........Page 482
Fig. 7. Structural section across Saih Hatat, following the same section as .........Page 483
Geodynamic patterns of ophiolites and marginal basins in the Indonesian and New Guinea regions......Page 490
Fig. 1. Location map of ophiolites and marginal basins of the Indonesian .........Page 492
Fig. 2. Plate boundaries, active faults and marginal basin age of the ING .........Page 493
Fig. 3. Tectonic map of the eastern Indonesian region. Banda Sea marginal .........Page 494
Fig. 4. Crastal cross-sections of different collisional settings for ophiolite emplacement in .........Page 499
Fig. 5. Tectonic map of ophiolites and young marginal basins east of .........Page 501
Fig. 6. Spatial and temporal correlation between marginal basin and ophiolite genesis, .........Page 506
Forearc ophiolites: a view from the western Pacific......Page 516
Fig. 1. New Caledonia and New Guinea: trenches, rises and ophiolites. The ........Page 517
Fig. 2. Gravity profiles compared, for the Bonin Arc, New Caledonia and .........Page 518
Fig. 3. Bathymetry, onshore gravity and ultramafic rocks in the New Caledonia .........Page 519
Fig. 4. NE Papua New Guinea. Black triangles indicate active and Recent .........Page 520
Fig. 5. The double subduction zone in NE Papua New Guinea, after .........Page 521
Fig. 6. Schematic illustration of phases in the development of the Marum .........Page 522
Tethyan- and Cordilleran-type ophiolites of eastern Australia: implications for the evolution of the Tasmanides......Page 526
Fig. 1. Map of the major geological elements of Australia. Ophiolites occur .........Page 527
Fig. 2. Map of western Tasmania, showing major structural and lithotectonic elements, .........Page 528
Fig. 3. Map of the Lachlan Orogen, and eastern Delamerian Orogen showing .........Page 530
Fig. 4. (a) Simplified map of the northern and central segments of .........Page 531
Table 2. Summary of petrological and geochemical data from Howqua and Dolodrook, Mount Wellington Belt......Page 534
Table 4. Summary of petrological and geochemical data from Jamieson and Licola, Barkly River Belt......Page 538
Table 5. Measured Pb isotope ratios and run errors, calculated radiogenic Pb ratio, .........Page 539
Fig. 8. (a) Map of the New England Orogen showing the major .........Page 540
Fig. 9. (a) Schematic tectonic diagram showing island-arc and related forearc crust, .........Page 544
Table 1. Summary of petrological and geochemical data from the Heathcote Belt......Page 533
Table 3. U–Pb zircon data from gabbro pegmatite from the Dookie quarry and tip site......Page 535
Table 6. Summary of the main features of eastern Australian ophiolites......Page 542
Ophiolites in China: their distribution, ages and tectonic settings......Page 550
Fig. 1. A generalized map showing the major tectonic blocks and erogenic belts of China.......Page 551
Fig. 2. A generalized map showing the distribution and age of major ophiolites in China.......Page 552
Fig. 3. Chondrite-normalized REE and MORB-normalized spider diagrams for ophiolites (chondrite and .........Page 555
Fig. 4. Ti–Zr (Pearce & Cann 1973) and Ta–Th–Hf (Wood 1980) diagrams. Legend .........Page 556
Fig. 5. A map illustrating the general geology and distribution of ophiolites .........Page 557
Fig. 6. The distribution of West Junggar ophiolites (after Bai et al. 1995).......Page 558
Fig. 7. The distribution of East Junggar ophiolites (after He et al 1990).......Page 559
Fig. 8. The general geology and distribution of ophiolites in the west .........Page 560
Fig. 9. The general geology and distribution of ophiolites in Inner Mongolia (after Tang & Shao 1996).......Page 561
Fig. 11. Cross-section of North Qilian ophiolites (after Zhang et al. 1997).......Page 562
Fig. 12. The distribution of Palaeo- and Neo-Tethyan ophiolites. Palaeo-Tethyan ophiolite zone: .........Page 563
Fig. 13. Geological map and cross-section of the Shuanggou ophiolite section, Yunnan Province. For abbrevations see Fig. 12.......Page 564
Fig. 14. Geological map and cross-section of the Babu ophiolite, Yunnan Province.......Page 565
Fig. 15. A cross-section sketch of the sheeted dyke swarm in the .........Page 566
Fig. 16. Geological map and cross-section of the Dingqing ophiolite, Bangong Lake–Nujiang suture zone.......Page 567
Fig. 17. Major geological units and distribution of ophiolites in Taiwan (after Ho 1977).......Page 568
Fig. 18. A map showing the presumed tectonic environments of formation for the major ophiolites of China.......Page 569
Fig. 19. Schematic temporal–spatial map of China showing the development of the .........Page 572
Table 1. Major oxides and trace elements for selected ophiolites in China......Page 553
Mineral chemistry of ultramafic massifs in the Southern Uralides orogenic belt (Russia) and the petrogenesis of the Lower Palaeozoic ophiolites of the Uralian Ocean......Page 576
Fig. 1. Geological map of the Southern Urals showing the location of .........Page 578
Fig. 2. Geological map of the Nurali–Voshnezenka area (after Saveliev et al. 1998). .........Page 580
Fig. 4. Geological map and cross-section (redrawn from Denisova 1984) of the .........Page 581
Fig. 5. Petrographic features of spinel–plagioclase and spinel Iherzolites from Nurali and .........Page 583
Fig. 6. Variation diagrams of A1[sub(2)]O[sub(3)] (a) and CaO (b) vs. MgO .........Page 589
Fig. 7. Chondrite-normalized REE patterns for the Nurali (a) and Mindyak (b) .........Page 590
Fig. 9. Major element composition of plagioclase from Nurali Iherzolites (P. Spadea, unpublished .........Page 591
Fig. 10. Cl-normalized (Anders & Grevesse 1989) REE patterns (a, c, e) and .........Page 595
Fig. 11. Cl-normalized (Anders & Grevesse 1989) REE patterns (a) and extended .........Page 596
Table 1. Main petrographical and geochemical characteristics of the analysed Nurali and Mindyak mantle peridotites......Page 582
Table 2. Bulk-rock major (XRF data) and trace element (ICP-MS data) composition of .........Page 586
Table 3. Trace element compositions (ppm element, except TiO[sub(2)] as wt%) of .........Page 592
Petrological diversity and origin of ophiolites in Japan and Far East Russia with emphasis on depleted harzburgite......Page 606
Fig. 1. Petrological types of ophiolites, after Ishiwatari (1991), and examples of .........Page 607
Fig. 2. Location of major ophiolite belts and ophiolite complexes in the .........Page 608
Fig. 3. Compilation of spinel Cr-number and A1[sub(2)]O[sub(3)] content of coexisting orthopyroxene .........Page 610
Fig. 4. Relationship between anorthite (An) content of plagioclase and Mg-number (= Mg/(Fe + Mg)) .........Page 611
Fig. 5. Geological map of the DH-type Shelting Cape ophiolite in central .........Page 615
Fig. 6. Geological map and schematic cross-section of the Elistratova ophiolite in .........Page 616
Fig. 7. Ophiolitic rock complexes of the Mainits Zone in the Koryak .........Page 617
Fig. 8. Geological map of the DH-type Mt. Krasnaya ultramafic complex (possibly .........Page 618
Fig. 9. (a) Tectonic framework of the Western Pacific area (with cross-section .........Page 620
Table 1. Ages of the ophiolities and blueschists of the northwestern Pacific margins from Japan to Russia......Page 609
Table 2. Representative mineral analyses of residual peridotites from ophiolite complexes in Hokkaido and northeastern Russia......Page 613
Ophiolites in accretionary complexes along the Early Cretaceous margin of NE Asia: age, composition, and geodynamic diversity......Page 628
Fig. 1. Tectonic map of NE Asia (by S. D. Sokolov and G. Ye. .........Page 629
Fig. 2. Reconstruction showing continental growth of NE Asia (after S. D. Sokolov 1992).......Page 630
Fig. 3. Taigonos segment of the Uda–Murgal island arc (Late Jurassic–Early Cretaceous).......Page 632
Fig. 4. Tectonic map of the Taigonos Peninsula (after Sokolov et al. 1999).......Page 634
Fig. 5. Map showing tectonic units of the Cape Povorotny accretionary complex (after Sokolov et al. 1999).......Page 635
Fig. 6. Network of plagiogranite veins in gabbro–diabase from blocks in the Main Mélange zone.......Page 636
Table 1. Major (wt%) and trace (ppm) element contents of gabbro–diabases and .........Page 637
Fig. 10. Chondrite-normalized (Sun & McDonough 1989) REE patterns for plagiogranites from .........Page 638
Fig. 11. Chondrite-normalized (Anders & Grevesse 1989) concentrations of REE (a) and .........Page 641
Table 3. Representative spinel compositions from the peridotites of the Yelistratov Peninsula ophiolite complex......Page 642
Table 5. Rare earth element contents of peridotites of the Yelistratov Peninsula......Page 644
Fig. 15. Geological map of the Penzhina segment (after Sokolov et al. 1996).......Page 646
Fig. 17. Geological map of the central Ganychalan terrane (by V G. Batanova & A. V Ganelin).......Page 647
Fig. 18. Chondrite-normalized (Sun & McDonough 1989) REE patterns of mafic plutonic .........Page 648
Fig. 20. Chondrite-normalized (Sun & McDonough 1989) REE patterns for plagiogranites and .........Page 651
Fig. 21. Chondrite-normalized (Sun & McDonough 1989) REE patterns for hypothetical melts .........Page 652
Table 9. Tectonostratigraphic units of the Kuyul terrane......Page 653
Fig. 23. Mineral composition features of ultramafic rocks from the Kuyul ophiolite .........Page 654
Fig. 24. Compositions of rock-forming and accessory Cr-spinels from ultramafic rocks of .........Page 656
Fig. 25. Chondrite-normalized (Anders & Grevesse 1989) REE patterns for the Gankuvayam sequence ultramafic rocks.......Page 658
Fig. 27. Chondrite-normalized (Sun & McDonough 1989) REE patterns for plagiogranites, and .........Page 659
Fig. 28. (a) Geological map of the Ust–Belaya terrane (after S. A. Palandzhyan); .........Page 660
Fig. 30. Plot of Cr/(Cr + A1) in Cr-spinel v. A1[sub(2)]O[sub(3)] in Opx and Na/Cr .........Page 662
Fig. 31. Temporal and spatial distribution of the ophiolites. u[sub(1)], Otrozhnaya nappe; .........Page 665
Table 2. Spinel composition (wt%) from Cape Povorotny peridotites, Taigonos Peninsula......Page 639
Table 4. Representative olivine composition from the peridotites of the Yelistratov Peninsula ophiolite complex......Page 643
Table 6. Major (wt%) and trace element (ppm) contents in dykes and lavas of the Yelistratov Peninsula ophiolite......Page 645
Table 7. Major (wt%) and trace (ppm) element contents of magmatic rocks of the Ganychalan terrane......Page 649
Table 8. Major (wt%) and trace (ppm) element contents of clinopyroxenes from .........Page 650
Table 10. Representative microprobe analyses of Cr-spinels in ultramafic rocks from the Gankuvayam sequence......Page 655
Table 11. Major (wt%) and trace (ppm) element contents of ultramafic rocks of the Gankuvayam sequence......Page 657
Table 12. Major element contents (wt%) of ultramafic and mafic ophiolitic rocks of the Ust–Belaya terrane .........Page 661
Table 13. Major element contents (wt%) of coexisting minerals from ophiolitic peridotites of the Ust–Belaya terrane......Page 663
Table 14. Age, composition, structural location and geodynamic setting of NE Asia ophiolites......Page 666
Rocas Verdes ophiolites, southernmost South America: remnants of progressive stages of development of oceanic-type crust in a continental margin back-arc basin......Page 674
Fig. 1. Simplified geological map of the southernmost Andes, modified after Dalziel .........Page 675
Fig. 3. Map showing the major lithotectonic units of southernmost South America .........Page 676
Fig. 4. Sequential lithotectonic sections (across XY in Fig. 3) during the .........Page 677
Fig. 5. Geological maps of the regions around the Sarmiento and Tortuga .........Page 679
Fig. 6. Schematic sections across the Sarmiento and Tortuga ophiolite complexes, modified .........Page 680
Fig. 7. Schematic cross-sections through three parts of the Rocas Verdes basin .........Page 681
Fig. 9. Rare earth element (REE) concentrations, normalized to the REE content .........Page 682
Fig. 10. Histograms illustrating the distribution of metabasalts and metagabbros, from the .........Page 683
Fig. 11. Sr v. Nd initial isotopic composition of cumulate plagioclase and .........Page 684
Fig. 12. Selected igneous and tectonic elements associated with the fission process .........Page 686
Proterozoic ophiolites of the Arabian Shield and their significance in Precambrian tectonics......Page 694
Fig. 1. Simplified geological map of the Arabian–Nubian Shield showing the distribution .........Page 695
Fig. 2. Simplified tectonic map of the Arabian Shield showing the occurrence .........Page 698
Table 1. Occurrence, age and classification of Proterozoic ophiolites in the Arabian Shield......Page 697
A......Page 710
B......Page 711
C......Page 712
D......Page 713
G......Page 714
I......Page 715
K......Page 716
M......Page 717
N......Page 718
O......Page 719
R......Page 721
S......Page 722
T......Page 724
Y......Page 725
Z......Page 726