Index

Page numbers in italics refer to figures, those in bold to tables

Abontorok ring complex 365-6 post-magmatic 138 absarokite 104 by seawater 394 acid porphyrites 196 alumina saturation 370 acmite 63, 149, 341,405,417 alvikite 53, 72, 73, 75, 77, 78 actinolite 387 AmbaDongar, carbonatite 71 adamellite 449 amphibole 2, 3, 7, 8, 9, 34, 45, 72, 77, 90, 92, 108, 137, Admapluton 388, 389 138, 160, 161, 170, 193, 198,202, 243,258, 271, Adrar Bous ring-complex 366 337, 338, 341,364, 386, 387, 388, 405,409-11, aegirine 71, 75, 77, 156, 338,386, 387,405,409, 411, 420, 437,439, 451,466, 520, 521,527 452, 479,484, 539, 541 alkali 133, 135, 156, 160, 479, 540 Zr-rich 461 Ba-K-amphibole 198 aegirine-augite 71, 75, 337, 338, 339, 405,409, 411 Ca-amphibole 387 aenigmatite 387, 417,452, 461,479, 539, 541 crystallization of 387 African Plate, movement of 282-3 pargasitic 63 agglomerate 136, 403,404, 502 secondary formation 465-6 agglutinate tuff see piperno sodi-calcic 370 agpaites 473,476, 539 stability of in basaltic magma 228 agpaitic rocks (Ilimaussaq intrusion) Ti-amphibole 198 bottom rocks 481-3 amphibole fractionation 523 mineralogy and layering 481-2 amphibolite 360 theories of formation of kakortokite layering amygdales 213 482-3 analcime 108, 120, 123, 132, 133, 138, 160, 163,202, roof rocks 478-80 217, 338, 405,484, 517,519 layering 479-80 origin of 48 mineralogy 478-9 primary 29 AillikBay, Labrador 128, 163 analcite basalt 140 aillikite 128, 198,465 anatase 131,133, 135, 138, 163 akerite 437 anatectic melts 508, 509 gtkermanite 31,32 anatexis 48,468 albanites 107 crustal 468 albite 48, 65, 72, 77, 109, 137, 149, 164, 198, 370, 373, andesine 388 387, 484 andesite generation, models for 394 destabilization of 374 andesite 68, 104, 128, 381,504 secondary formation 465-6 basaltic 233 albite-aegirine schists 77 continental margin 261 albitites 77 potassic 140 albitization 78,370, 374, 387 subduction-derived 132 alkali enrichment 92, 93 ankaramite 234, 495 alkali gain 317 ankaratrite 295, 301,303 alkali loss 72, 76, 78, 86, 87, 88, 92, 282, 317, 324, annite 371,373 420, 465 anorogenic complexes, within-plate 395 Zomba-Malosa complex 341 anorogenic magmatism alkali-depletion, volume requirements of 89 effect of late-stage fluids on 370-6 alkaline lamprophyre branch 196, 198, 200, 203,204, acid metasomatism 374-6 205,212, 214, 215,218,219 biotite granites and their mineralization 370 allanite 305, 387, 388 potassic metasomatism 373-4 zoned 387 sodic metasomatism 370, 373 Aln6 complex (Sweden) 53, 66 petrogenesis 366-70 aln6ite 68, 128, 136, 138,219, 337, 339, 349, 442, 463, Phanerozoic anorthosite association, Air, Niger 464-5 363-6 CO2-rich 444 tectonic and structural controls 358-70 Ile Bizard 442 anorogenicmagmaticevolution 361-3 incompatible element concentrations 443 influence of Pan-African orogeny 358, 360-1 alteration 255,257, 337 tectonic constraints on alkaline magmatism 361 hydrothermal 135, 271,370, 407, 465,503, 524 anorthite 149 K-silicate 374 anorthoclase 420 metasomatic 170, 351 anorthoclase trachyte 234 Na-silicate 370 anorthosite 361,363, 364, 450, 466, 531 545 546 Index

anorthosite (cont.) Baikal-Aldan Belt, USSR 140, 143 Air 363,364 Baltic Shield (Kola Peninsula), alkaline rocks of 531- labradorite-andesine 461 43 massif-type 449 Palaeozoic alkaline complexes 533-43 anorthositic complexes, evolution of 366 Proterozoic alkaline complexes 531-3 anorthositic enclaves 368 Bambouto, Cameroon 278 apatite 57, 66, 67, 68, 71, 72, 73, 77, 90, 91, 97, 108, barite 71, 74, 78, 109, 133, 138,462 109, 114, 122, 129, 13l, 132, 133, 138, 139, 164, Sr-barite 120, 122, 164 166, 168, 234, 243,305, 337, 338,339, 349, 387, barroisite 387 388,405,409, 451,462, 465, 468,475,479,492, bartonite 200 521,541-3 baryte see barite early-crystallizing 466 basalt 5, 8, 35, 68, 104, 107, 139, 154, 255,259, 271, Na-REE-rich 462 273,278, 279,280, 281,282, 284, 309, 314-15, apatite deposits 534, 541-3 317, 318, 321,323,423, 442, 452, 454, 459,465, apatite glimmerite 139, 163 504, 520, 521,524 aplite 405 alkali 19, 30, 45, 103-4, 148, 151,167, 179, 196, aplogranite 407, 409 232, 258, 262, 293,294, 296, 297,298, 300, 301, albite 373 302, 307, 417,444, 493, 517 aqueous fluid phase, separation of 92, 93 evolved 37 aqueous fluids 23 fissure-fed 303 and alkali loss 86, 88 genesis of, Massif Central 526-7 development from magma 88 alkali olivine 15, 32, 33, 34-6, 298,442, 444 arfvedsonite 71, 72, 77, 337, 386, 387, 411,417,479, alkaline, transitional 296, 298-9, 303, 304, 307, 309 481,482, 483,484, 539 analcite 140 K-Ti-Mg-arfvedsonite 156 continental margin 261 Mg-arfvedsonite 77 ferrobasalt 296, 298,303 arfvedsonite-riebeckite 452 Gardar 456, 460 Argorintrusion (Canada) 90 genesis of 30 Argyle, E Kimberleys, W Australia 131,142, 144, K-rich 128 148, 149, 151,163 leucite 140 diamondiferous tuff 104 oceanic 381 armalcolite 108, 123, 163, 165 olivine 294, 298 Ascension Island 253-61,269-71 olivine-augite 303 Ascutney Mountain complex 441 primary 443 ash-flows 421,423 shoshonitic 135 comendite 303 subduction-derived 132 assimilation 313,425,452, 508,524 tholeiitic 230, 232, 241,435,444, 495 asthenosphere 4, 21,284 trachybasalt 315 generation of parental magmas 357 Walvis Ridge 263,264 partial melting of 64, 65, 283-4 basalt-trachyte relationships 320-3 as primitive mantle source 398 fractional crystallization of basaltic magma 320-2 asthenospheric bulge 517 partial melting of mafic deep continental crust 323 asthenospheric plumes 24 significance of composition gaps 322-3 astrophyllite 387,405,452 basanite 2, 3, 4, 10, 15, 32, 36-7, 196, 232, 277, 278, augite 61, 71,107, 128, 135, 137, 234, 282, 339, 386, 280, 282, 294, 296, 297, 301,317, 442, 504, 506, 409 517, 519, 524, 526 Fe-augite 387 leucite 135 sodian 410 nodules in 6 T-Al-augite 62 olivine 39 augite syenite 451,452, 474, 499 bastnaesite 71, 73-4 Australia, generalized map 129 batholiths 381 autometasomatism 370 calc-alkaline, Iforas 398 Azores 10-11 Sierra Nevada 127 Azzaba, Algeria 136-7 unroofing of 394-5, 398 W Iforas (composite calc-alkaline) 382, 388,398 White Mountain 433-4, 435 Ba mineralization 57 beforsite 53,465 Ba-K-amphibole 198 Belknap Mountain complex, geology of 434-5 Ba-K-feldspars 198 Benfontein (S Africa) 65 Ba-K-phlogopite 198 Benin-Nigeria shield 360 Ba-Ti-phlogopite 198 Benioffzones 144, 381 back-arc spreading 427 fossil 143, 168 baddeleyite 71,405,424 benmoreite 37, 234, 296, 298,303, 304, 321,322, 323, Bagnold effect 306, 369 417, 521 Index 547

Benue trough 362 Ca-amphibole 403 related to Cameroon line 283 calc-alkaline lamprophyre branch 196, 198, 200, 202, bimodal suites 278 203, 204, 205,212, 214, 215, 217, 218, 219 bimodality 65, 67, 304, 307, 308, 309, 341 calcite 54, 66, 67, 69-70, 71, 73, 89, 90, 91,133, 135, basalt-trachyte volcanism (Gregory rift) 299 138,203,462, 467 magmatic 5-6 in lamproite 97 transitionally alkaline suites (Kenya) 293, 303, calcite carbonatite 53, 72, 73 304 caldera collapse 228, 234, 278, 305,308, 309, 315, Bioko (Fernando P6o) 280 320, 322, 324, 325,330, 331 biotite 37, 71, 72-3;73, 77, 90, 104, 137, 200, 214, caldera complexes 433 320, 337, 338,339, 349, 383, 387, 405,420, 451, caldera formation 314 465, 521 Krakatoa-type 315, 331 annite-rich 462 caldera volcanoes 313-15 castellated 193 calderas 271,278,299,421,422, 423,425,428 F-bearing 466 trachytic 315 green 388 Cameroonline, W Africa 273-89 Mg-biotite 387 age 273-4, 277 biotite granite 436, 452 geology and petrology 277-82 mineralization of 370, 371,372 continental sector 277-80 biotite mafurite 39, 42, 165 oceanic sector 280-2 biotite peridotite 464 mantle sources and generation of the basic magmas biotite pyroxenite 464 283-6 biotite ugandite 165 origin of 282-3 biotite-annite 387 salic rocks, origin of 286-9 biotite-phlogopite 193,202 Cameroon, Mount 279 Biu Plateau, Nigeria 277-8 camptonite 212, 219, 339, 349, 352, 442, 493, 508 blairmorite 335 Canary Islands 54, 63 block faulting 144 Canaveseline 133 Blosseville Kyst shelf 489-90 cancarixite 132 Bobi-Sequela, Ivory Coast 136, 144, 149, 163 cancrinite 65, 66, 338,405,467, 534 Bohemian Massif, Czechoslovakia 135 Canning Basin, W Australia 129, 130 Borrolan syenite (NW Scotland) 75 Cape Verde Islands 54, 64, 67, 69, 143 bottom cumulates 479 carbonate 3, 7, 8, 9, 132, 193, 203, 338,349, 468 boundary layer 308 primary magmatic 467 boundary-layer liquids 306 secondary formation 465-6 boundary-layer migration 331 stability of 166 Bouvet Island 253-61 carbonate-saturated system ((Si + A1) - (Na + K) - Ca) Brazil 140 68 Brazilian Precambrianshield 403 carbonatite olivines 90 breccia 122, 123, 136, 139, 144, 212, 405,437, 498, carbonatites 29, 38, 44, 68, 69-74, 86, 109, 128, 196, 499, 502, 503, 508,542 215,296, 297, 306, 336, 337, 339, 354, 376, 383, autolithic 142 442, 444, 462-5,492, 534, 535 contact intrusive 124 alkalic, development of 92 hyaloclastite 280, 282 calcitic-dolomitic 89 igneous 437 calcite 53, 72, 73 intrusive 436 calcitic toankeritic 86 lamprophyric 8 defined 53 pyroclastic 142 dolomite 53, 72, 73, 75 quartz porphry 499 intrusive 71-3 rheomorphic 441 liquid immiscibility and genesis of 45, 47 syenite 365, 501 mineralization 73-4 volcanic 503 natrocarbonatite magma 69-71 breccia pipes 436 and nephelinites 53-79 breccia plugs 503 normal, development of 91-2 brecciated greisens 375 carbonatization 535 brecciation 67, 79 Cargillcomplex (N Ontario) 65 of roof 484 cassiterite 277, 375, 376, 405 roof cumulates 474 catapleiite 417,424 breunnerite 203 cauldron subsidence 383,452, 499, 503 britholite 405,409 cedricite 108 BultfonteinMine 100, 170 centralcomplexes, Gardar province 450-2 Bultfontein pipes, S Africa, inclusions from 24 Cerro Manomo, carbonatite complex, silicified 403 buoyant ascent 306, 308 CH~ fugacity 541 buoyant transport, of magma 233 chalcopyrite 376 548 Index

(~hannel-Island lamprophyres 135 contamination 437 Chaone complex 336, 337 crustal see crustal contamination metavolcanic rocks 339 of mantle 23 nepheline syenite and syenite 338, 341-4, 345,347, of OIB source region 265 351 radiogenic Sr from groundwater 425 charnockitic rocks 360 sea-water 271 Chelima, India 139, 141, 142, 144, 149, 151,163 sedimentary 264 Chikalacomplex 336, 337, 339 selective 412 nepheline syenite and syenite 338,341-4, 345,347, continental margins 106 351 continental regions, isotopic data 19-20 quartz syenites 352 convecting upper mantle, as source of MORB 285 Chilwa alkaline province (N part) convection 450, 482 petrochemistry of 335-54 double-diffusive 478, petrography 337-9 convective flow 542 Chilwa Island, carbonatite complex 337, 339, 351 convective mixing 324-5 dykes 339 convective overturn 325,326, 482, 543 nepheline syenite and syenite 338,345-6, 348, 349, Cr-diopside 61, 62, 122 352 Cr-pyrope 122 Chinduzi complex 336 Cr-spinel 114, 123, 132 nepheline syenite and syenite 338, 341-4, 345, 347, Crater of Diamonds State Park, Prairie Creek, 351 Arkansas 97, 104, 107, 122-3, 125, 142, 144, Chino Valley, Arizona 128 146, 148, 156, 160, 163, 168 chkalovite 484 crater lakes 278 chlorite 108, 132, 164, 369, 374, 387, 388 cratons 21, 22 chromite 120, 123, 133, 135, 136-7, 136, 137, 138, 163 crust-mantle system, models for chemical Ti-Mg chromite 131 evolution of 261-2 Zn-Mg-chromite 204 crustalassimilation 166, 452 cinder cones 120, 142, 143, 234, 277,278,279, 280, crustal attenuation 453 282, 517 crustal contamination 24, 63, 154, 155, 165, 168, monogenetic 298 253,273, 286, 287, 293, 323,332, 394, 407, 408, clinohumite 77 412, 435,437, 439, 441,468,475, 509, 519 clinopyroxene 3, 7, 8, 32, 33, 34, 35, 36, 37, 38, 39, 40, agpaitic magma 475 41, 44, 45, 56, 108, 120, 133, 149, 156, 164, 165, fractionating magmas 287 167, 200, 202, 218, 258, 324, 326, 364, 365,368, mantle-derived melts 441 387, 388,420, 426, 458,465,467, 520, 524, 541 Massif Central magmas 523-5 acmitic 424, 541 progressive 407, 408 alkali 499 and silica-undersaturation 440 aluminous 279 crustal doming 361 analyses of 62 crustal extension 215, 330 clinopyroxenite 4 crustal intrusive processes 63-4 C1, role of 466-7 crustal melting 321,435 CO2 61, 64, 142, 349 crustal shear zone (Ngaound6r6 fault) 283 and magma genesis 36-44 crustal shortening 427 CO2 fugacity 86, 541 crustal thinning 427 COdH20 ratio 239 crustal weakness, pre-existing zones of, Coc Pia and Sin-Cao, Upper Tonkin, N Vietnam controlling magmatism 444-5 138-9 crust, involved in magmatic processes 441 cocite 107, 138 cryolite 374, 466, 467 Colima Graben, Mexico 128, 146 cryophyllite 370 collision 360, 395 crystal accumulation 277 and calc-alkaline magmatism 398 crystal boundaries, migration along 73 Tuareg shield and W African craton 394 crystal fractionation 63, 92, 168, 170, 234, 255, columbite 370, 373, 376 269, 279, 281,285, 331,332, 351,352, 435,452, comendite 6, 269, 299, 331,341,452, 462 461,467,468,485,499 composition gaps 5-6,10 advanced 459-60 mafic and felsic Si-undersaturated rocks 417-18 closed-system 450 significance of 322-3 low-pressure 287 compositional gradients 478 mechanisms 323-4 concentration gradients 478 crystallayering, sub-vertical 411,412 cone sheets, alvikite 73 crystal settling 306, 313,482, 542, 543 cones (volcanic), overlapping 491 differential 478 conglomerates 280 crystal-liquid fractionation 304, 305, 306, 309, 351, conjugate immiscible liquids 72 428 contact metamorphism 218 crystal-liquid processes, low-pressure 255 Index 549

crystallization 308, 329 diapirs 47 of amphiboles 387 asthenospheric 427 of anhydrous minerals 91 diatom ooze 264 downward 480, 508 diatremes 114, 129, 142, 144, 193,436, 517 intermittent 482 inIndia 139 low-pressure 32 kimberlite 54, 95, 142, 143 shallow 318 lamproite 122, 142, 143 Ti-magnetite 461 diatremic eruption 8 crystallization processes 323 diatresis crystallization rate, increase in 485 liquid 9 crystals mafic melt 8-10 flow sorting of 366 differentiates, high-pressure 506 gravitational separation of 482 differentiation 5, 39, 86, 219, 233,249, 341,408,437, cumulate blocks, hornblende-rich 288-9 462, 541 cumulate layering 466 carbonatite magmas (computer modelling) 90 cumulates 62, 72, 77, 219, 236, 269, 387, 437 continuous 6-7, 11 anorthosite 368,461,468 crystal-liquid 407 bottom 474 due to crystal fractionation 235 clinopyroxene 460, 492 extreme 539 dunite 492 geological evidence for depths of 318-20 flotation 461,479 insitu 451 gabbroic 331,451 influence of magma chamber processes 306 layered 451 liquid-state 303,450 leuconorite 368 low-pressure 293 olivine 237,249, 492 shallow 320 plagioclase-rich 320-1 differentiation mechanisms 331 pyroxene 237 differentiation processes, complex 168 pyroxenite 64, 492 diffusion 481,483 roof 474 diopside 21, 30, 32, 49, 96, 97, 108, 109, 114, 123, sodalite (naujaites) 467 129, 131,132, 133, 135, 136, 138, 139, 148, 156, syenogabbroic 451 165, 166, 168, 170, 217 troctolitic 461 Cr-diopside 61, 62, 122 wehrlite 492 ferri-diopside 200 cumulus augite 421 Ti-diopside 114 cumulusnepheline 421,428 diorite 360, 366, 433, 434, 436, 437, 439, 441 cumulus olivine 436-7 porphyritic 436 cumulus processes and carbonatite rock types 92 disaggregation 321 cumulus sequences 442 disequilibrium melting 217 cumulus tabular perthite 405 disequilibrium textures 525 cumulus textures 411,438,439 distension 361,395 current bedding 482 djerfisherite 200 Cuttingsville complex, geology of 436, 440 dolomite 39, 71, 73, 89, 90, 91 ferroan 139,203 dacite 104 dolomite carbonatites 53, 72, 73, 75, 78 Daly gaps 296, 299, 301,303, 305 dolomitization 203 dalyite 135, 164, 269 domal uplift 361 davanite 123 domes, diorite 499 Deep Springs Valley, California 127, 155-6 doming 353-4 degassingofH20 271 resurgent 422 dehydration 262, 264 dunite 61,167, 460, 534 down-going oceanic lithosphere 394 recrystallized 235 density control 461 dyke-swarms 335, 381-2, 382, 383, 388-9, 395, 398, density hump 307, 308 426, 451,456, 476, 491,495,498 ferrobasalt 308 acid 398 density inversion 39 basic 454 density sorting 482 Fox Bay 455 depletion events 20,168 Gardar, distribution and chronology 453-7 desilication 405,406 lamprophyre 215 deuterium, depletion in 271 radial 422 diamond sources, primary 198 tholeiitic and alkaline, genetic link 508 diamonds 24, 95, 97, 104, 114, 120, 122, 131,136, dykes 129, 138, 142, 236, 280, 365,403,421,433, 503 139, 164, 167, 168 agpaitic 461 diapiric segregations 418 albitite 531 diapiric uprising 39 alkali olivine basalt 438 550 Index dykes (cont.) spessartite 454, 531 alkaline syenite 534 syenite 120, 135 aln6ite 339, 438 tholeiitic 493 aln6ite-monchiquite 454 tinguaite 535 alvikite 73 trachyte porphyry 535 basaltic 282 ultramafic lamprophyre 463,464, 465 basanite 282, 438 ultrapotassic 133,463,464, 465 bostonite 531 Velasco province 405 camptonite 339, 355,438,493, 508 carbonatite 47,467 E African rift system 6, 136, 293, 335 ChannelIslands 135 tectonic evolution of 293-4 Chilwa Island 337 eclogite 217 concentric 339 edenite 387 diabase 531 element mobility 257 doleritic 454-5 emeleusite 462 felsic 438,440 Emuruangogolak 305, 306, 314, 315, 316, 317, 320-1, felsite 383 323, 324 Fortification dyke, Colorado 127 trachytes 321-2 giant, Gardarprovince 450-2 enclaves, anorthositic 368 hawaiite 426, 451 Enoree Vermiculite district, S Carolina 109 Holsteinsborg 116 enriched zone 8 ijolite 339 enrichment events 100, 168,237 kersantite 454 double-enrichment event 265 kimberlite 114 enrichment processes 4 lamproite 114, 123-4, 127, 142 enstatite 32, 40, 41, 44, 122, 165, 166 lamprophyre 195,219, 495,499, 502, 535 epididymite 462 lamprophyre dyke, Helam mine 96, 97 epidote 369, 387, 388 late-Gardar 456 epithermal neutron activation analysis (NAA), trace lujavrite 478, 538 elements, OIBs 254-5 malignite 534 equilibrium melting, MORB source 286 melasyenite 138 erdite 200 mica peridotite 120, 131 erosion 278,418 microfoyaite 338 erosion, selective 142 microgranite 337 eruption sequence, Hawaiian 227, 230 microsyenite 337 post-caldera alkalic stage 228, 230, 234-7 minette 128 post-erosionalalkalic stage 230, 237-8 monchiquite 438,442 pre-shield alkalic stage 227, 230, 232-3 nephelinite 339 tholeiitic shield-building stage 227-8,233-4 Nunarssuit-Isortoq 460 eruptions okaite 436 basalt 308 olivine basalt 451 diatremic 8 olivinelamproite 131 explosive 234, 271,307-8,309, 331 orientation of, Trans-Pecos 426 fissure, basaltic 320 oversaturated 341 high-velocity 4, 8, 9, 10 peralkaline rhyolite 501 OldoinyoLengai 86, 87, 88 phlogopite-olivinelamproite 120 preferential, of salic magmas 308 phonolite 337, 338, 339, 349, 350, 354 pyroclastic 309 pillow 499, 504, 508 shield-building 309 porphyrite 531 small-volume 232, 237 porphyry 383 basalt 233 potassic 493 trachytic 309 prowersite 128 tufts, air-fall and ash-flow 315 quartz microsyenite 323 essexite 437, 531 rare-earth melasyenite 408-9 Etinde, Cameroon 279-80 rhyolite 303,383, 508 eudialyte 269, 338,405,417, 424, 452, 461,479, 481, ring dykes 337, 422, 434, 451,492, 503 482, 483,484, 538 monzonite-syenite 436 Exetervolcanics 135 nordmarkite 437 explosion craters 278,279 porphyritic quartz syenite 436 explosion craters, recent 297 syenite 495 extension 22, 426, 427 syenite-quartz syenite 433 extensional tectonics 320 saturated and oversaturated 337-8 sheared, meta-kimberlites 136 Farallon Plate 427 s61vsbergite 337, 341 fault lines 144 Index 55I

fault reactivation 357, 361 fluid phase, boiling of 375 fault swarms, Gregory rift 319 fluid phases 477 faulting, Basin and Range 426 fluid reactions, in biotite granites 370 faults 335 fluids, late stage 74 normal 319 fluoramphiboles 77 recent, distribution of (Kenya) 319-20 fluorapatite 71,77 tensional 361 fluorides 466 transcurrent 357, 361,362, 376, 383,389, 395 fluorine 386, 467 wrench 398 fluorine fugacity 77 fayalite 45, 47, 324, 337, 370, 386, 387 fluorite 71, 78, 92, 198, 338,374, 383, 387,420, 462, Fe enrichment 307 466, 467 Fe-augite 387 precipitation of 74 Fe-dolomite 139, 203 secondary formation 465-6 Fe-Ti tholeiites 504-5 flux melting 7 feldspar 7, 29, 49, 73, 75, 138-9, 144, 146, 202, 279, flux migration 7, 8 387, 475,479, 481,482, 541 Fort Portal(SW Uganda) 72-3 alkali 77, 337, 338, 349, 373,420, 451,462, 479, Fortification dyke, Colorado 127 521 forsterite 44,97, 149, 217 Ba-K-feldspars 198 fortunite 103, 132 K-feldspar 71,160, 193, 198,217, 339, 387 foyaite 338, 342, 343, 349, 353,405,407,408,410, feldspar (alkali) fractionation 304 411,412, 436, 437, 451,462, 466, 467, 474, 475, feldspathoids 7, 29, 144, 146, 149, 160, 198,202-3, 478,499, 508, 535, 537 338,438 sodalite 478,479 felsic alkaline rocks 45-49,417,419-20, 433,435, fractional crystallization 5, 34, 68, 86, 87, 93, 104, 438 255, 303, 313, 331,423, 525 felsite 503 of basaltic magma 320-2 Fen (S Norway) 66, 74 closed-system 318 fenites 66, 72, 76, 86, 342, 534 hornblende-bearing assemblages 288-9 aegirine-albite 77 low-pressure 365 feldspathic 77 Massif Central magmas 520-3 K-rich 77, 78, 339 nephelinitic and ijolitic magmas 65 mobilization of 351 olivine s6vite magmas 90, 92 syenitic 77, 78 problems 326 fenitization 2, 53, 69, 72, 74-7, 78, 92, 341,351,412, fractional melting 6, 167,423 436 fractional resorption 170 carbonatite 77 fractionation 56-7, 60, 62, 63, 64, 68, 72, 77, 104, earlyGardarlavas 465 105, 148, 166, 167, 217, 301,305,351,354, 428, N Chilwaprovince 336 434, 510 potassic and sodic 86 alkali feldspar 304, 341,351,408,412 silicate 77 amphibole 34, 351,521,523 fenitizing fluids 65-6, 93 carbonatite 75, 76 ferri-diopside 200 centripetal 365 ferrisyenite 368 clinopyroxene, extended 460 ferro-pseudobrookite 163 closed-system 321,492 ferroactinolite 373 of comendite magma 270 ferrobasalt 296, 298, 303 complex 33 ferrocarbonatite 53, 71, 72, 73, 75, 78 dry, basaltic magmas 460 ferrodiorite 449,450 dynamic 61 ferrosalite 475 early mafic minerals 387 ferrosyenite 450 eclogite 39 ferruginous clay 264 extreme 409 filter-pressing 417-18 fayalite 351 fitzroyite 97, 107, 108, 136 feldspar 326 flood basalt 449,454 high-level 343, 352 continental 459 in situ 466 Tertiary, Greenland 458 intense, of K-feldspar 387 flood lavas 423 K/Na 44 flotation cumulates 461,479 low-pressure, benmoreite residues 461 flow differentiation 365 and magma chamber layering 368 flow sorting, crystals 366 magnesian magmas 281-2 fluid evolution, stable isotope constraints 271 nephelinite, olivine-poor 55 fluid immiscibility 270 olivine 36, 37, 38, 39 fluid inclusions 66, 67, 68, 72, 376, 467, 481 extended 460 Ascension I., granite xenoliths 270 phlogopite 149 552 Index

fractionation (cont.) gieseckite 405 plagioclase 260, 301,304, 307, 412, 521 glimmerite 16 pyroxene 61-3,351 apatite 139, 163 sphene 521 globular structures titanomagnetite 307 felsic 193 U-Pb 524 lamprophyres 213-15 see also crystal fractionation; liquid fractionation; gneiss 77, 128,278,337, 360, 506, 534 crystal-liquid fractionation Archaean 498,499 fractionation trends 32 crustal 508 fracturing 361 Gondwanacoalfields, India 139, 142, 151 Gondwanaland 137, 357, 360 fragmentation of 361 gabbro 71,196, 273, 361,363,433,436, 437,439, 466, Gough Island 253-61 493,498, 502, 531 grabens 294 kaersutite 499, 508 Graciosa (Azores) 6, 7, 11 leucogabbro 361,363, 366, 369,437 grain boundaries 2, 8 Lilloise 501-2 granite 104, 105, 273,278, 336, 337, 339, 341,346, miarolitic 318 351,361,363,383,386, 405,408,421-2, 433, olivine 531 435,441,462, 495,498, 499, 502, 503, 508, 509 tholeiitic 495, 497-8 A-type 398,462 gabbro-diorite 503, 531 albite 370, 373 gabbro-norite 531 alkali 384-5,433,451,533 galena 376 biotite 361,434, 436, 437,452 galena deposits, Pb isotope compositions 504 mineralization of 370, 371,372 Galore Creek, British Columbia 128 of crustal origin 440 Gardar Province, S Greenland 449-68 crystallization of 270, 271 alkali metasomatism in vicinity of Gardar foliated 360 intrusions 465-6 green, Ilimaussaq 462 anorthosite cumulates and benmoreite residue hastingsite biotite 434 461 hypersolvus 383, 385 carbonatites and ultramafic lamprophyres 462-5 metaluminous 384 central complexes and giant dykes 450-2 peralkaline 386 compositions of Gardar basic rocks 457-60 metaluminous 376, 387, 389 cycles of Gardar magmatism 453 biotite 433-4 distribution and chronology of Gardar lavas and monzogranites 361,388,389 dyke-swarms 453-7 peralkaline 269, 341,361,376, 384, 387, 389, 499 highly differentiated salic magmas 461-2 porphyritic 360 petrogenic summaryand conclusions 467-8 riebeckite 412 stratified magma chambers 452 S-type, absence of 394, 398 volatile components of Gardar magmas 466-7 sub-solvus metaluminous 391 garnet 33, 34, 36, 38, 41, 45, 97, 123, 164, 165, 218, two-mica 360 258 granite liquid permeation 370 melanitic 198 granite porphyries 383, 385, 387,434 residual 442-4 granitic minerals, instability of 374-6 Ti-Zr-garnet 200 granitic plutonism 218 garnet lherzolite 40 granitoids 360, 381,388,398, 399 garnet peridotite 2, 16-17, 21, 25 Iforas 394 gascontent oflavas 233 granodiorite 360, 388,436 gas coring 320 granophyres 399, 503 gasexsolution 9, 10 granulites 524 gas phase 541 charnockitic 336 gaseous transport 166 Iforas 393 gases lower crustal 467 hydrocarbon-rich 540-1 graphite 467 importance of 4, 9 graphitization, lamproite diamonds 168 Gaussberg, Antarctica 106, 137-8, 141,142, 149, gravitational crystallization differentiation 154, 156, 160, 163 (hypothesis) 543 gaussbergite 107 gravitational separation, of crystals 482 geochemistry, lithospheric control on 468 gravity anomalies, positive 360, 381,474 geothermal gradients 4, 7, 8, 10 gravity separation 91 geothermometry Greenland, East: Tertiary alkaline magmatism 489- in carbonatites 89 512 Fe-Ti oxide, Mont-Dore, France 521,523 alkaline dyke-swarms and associated lavas 493-5, geotherms, upward migration of 354 504, 506, 508 Index 553

Blosseville Kyst 501-2 HFS (high field strength) elements 425 discussion and petrological models 504-12 HighwoodMountains, Montana 127, 163 evolutionary trends 510-11 Hills Pond, Kansas 114, 121, 142, 144, 149, 156, 160, Gardiner complex 492-3, 504, 506 163 geochemistry 503-4 H20 in Ascension I. granite xenoliths and magmas Hold with Hope 503 270-1 Kangerdlugssuaqdistrict 498-501,504, 508 H20 and magma genesis 36-44 Kap Gustav Holm complex 495 H:O fugacity 86, 540 Kialineq centre 495, 497-8 H:O/COz ratios, low 165 Mestersvig area 502-3 Holmeade Farm, UK 133 Nualik centre 498 Holsteinsborg, W Greenland 114, 116, 120, 141,142, Prinsen af Wales Bjerge 491,504, 506 148, 149, 156, 160, 163 tectonic framework 489-91 Homa Mountain (W Kenya) 57, 69 Traill 503 hornblende 288, 369, 387, 388,405 Greenland, South: Gardar Province 449-68 paragasitic 410 Gregory rift 297, 301,302, 303, 318 hornblende monzonite 495 gregoryite 53-4, 69 hot spots 253,262, 263, 264, 361 greisen 373 transient 169 brecciated 375 HREE 149 greisenization 374-5 hydration 257 absence 540 hydrocarbons 540-1 groundwater 74 hydrothermal activity 517 contamination by 425 hydrothermal alteration 135,271,370, 407, 465,503, Guinea, Gulf of 280-2 524 hydrothermal discharge 230 hydrothermal fluids 74 Haleakala, lavas 242, 243 F-bearing 387 half-graben 294 hydrothermal overprinting 370 halides 193 hydrothermal veins 426 halite 467 hydrous fluids (LIL- and LREE-enriched), halogen loss 341 crystallization of 16 halogen-bearing systems 47-8 hypersthene 132,419 halogens 30, 77, 321,328,467 harzburgite 40 hastingsite 387, 451 icelandite 233 hastingsite biotite granite 434 Ichoualenring structure 383 hastingsite quartz syenite 434 Iforas (Adrar des Iforas), alkaline magmatism in hafiyne 109,279, 517, 519 381-99 Hawaiian alkaline volcanism 227-50 ages, isotopic and main geochemical characteristics eruption sequence 227-38 of the calc-alkaline and alkaline transition experimental constraints--depth of origin 238-9 389-92 geological setting 227 general geology 381-2 isotopic constraints on mantle sources 239-41 Pan-African orogenic context 388-9 rare-gas constraints on mantle sources 241-2 Iforas-Ahnet area, structural map 382 trace-element constraints on magma sources 242-6 igneous lamination 321 volume relations--magma storage at depth-- igneous systems, with K, Na and A1 104-6 xenolith assemblages 246-9 ignimbrite 278, 363, 382, 383, 389, 423,426 Hawaiian eruptive products 229 comenditic 361 Hawaiian Islands 227 rhyolitic 274, 278 Hawaiian volcano (hypothetical), evolutionary stages Iivaara (Finland), ijolite intrusion 67 248 ijolite 54, 60, 63, 66, 68, 77, 88, 296, 306, 339, 349, Hawaiian-Emperor volcanic chain 228, 229, 231, 241 436, 534, 535, 541 hawaiite 5, 15, 230, 234, 235,243, 255,259, 278, 279, ijolite-melteigite 532 280, 323,417, 426,454, 459,465,493, 495,506, ijolite-urtite 542 520 Ilimaussaq intrusion 473-85 nepheline 37 the agpaitic magma 475-8 3He/4He ratios 241-2 crystallization of 478 hedenbergite 370, 386, 387, 479 development of 475-6 Helam Mine, Transvaal 96, 97 properties of 476-8 hematite 74, 133, 373 bottom rocks 481-3 heterogeneities, caused by mantle metasomatism 44 final stages: the lujavrites 484-5 heteromorphism 215 geological setting 473-4 heulandite 164 roof rocks 478-80 HF and HC1 fugacities 539-40 structure of the intrusion 474-5 554 lndex ilmenite 73,90, 120, 132, 133, 135, 138, 139, 163, 164, nepheline syenite 301 170, 198, 203,204, 234, 364, 408 Iskou complex, anorthositic enclaves 368 magnesian 97 island arcs 106, 360 Mn-ilmenite 131 isotope studies, co-magmatism of Kenyan alkaline Imilik gabbro 497-8 series 305-6 immiscible liquids 440 isotopic data, Loihi lavas 232 immiscible separation 72, 86, 88, 90, 93 isotopic systems, to determine crustal contamination inclusion-bearing alkaline rocks 15-25 523-5 in continental rift valleys 18-19 Italy, NW 133, 142, 148, 149, 151,156, 160 in ocean basins 16-18 Roman Province 135, 155, 163, 165 in other continental regions 19-20 Tuscany 135, 155 inclusions apatite-amphibole pyroxenite 16 basalt 501 Jacupiranga, Brazil 73 garnet peridotite 16 jacupirangite 73,436 glimmerite 16 jeppeite 108, 129, 163,200 high-density 24 jumillite 103, 107, 108, 132, 133, 138 kaersutite gabbro 499 Jungunicomplex 337,352 mafic and ultramafic 18, 20, 21 nepheline syenite and syenite 338, 348 mantle 16 petrochemistry 344-5 MARID (mica-rutile-ilmenite-diopside)rocks 16 juvite 532, 541 mica clinopyroxenite 16 naujaite 484 picroilmenite 123 K enrichment 40, 41,42 saline 270 K-arfvedsonite 108, 138 spinel lherzolite 16 K-feldspar 71,109, 160, 193, 198, 217, 339, 387 spinel peridotite 16 K-for-Na exchange 374 vapour-rich 270 K-rich rocks, experimental studies 164-6 incompatible elements 459 K-rich volcanism 144 abundances 284-5,443 K-richterite 114, 120, 123, 129, 132, 133, 138, 160, depletion in 167 170 enrichment 237,439, 440 K-riebeckite 108, 123, 156 India, generalized geology 140 K-Ti-Mg-arfvedsonite 156 Indonesian arc volcanics 140 K-Ti-richterite 108, 156, 200 intra-plateactivity, Niger-Nigeria 358 K-trachyandesite 136 intra-plate volcanism 284 Kaangankunde (Malawi),carbonatite 74 intrusions 68,219 kaersutite 36-7, 37, 116, 169,202, 437 agpaitic 48 kaersutitegabbro 499, 508 alkali gabbro 45 Kaiserstuhl(S Germany) 54, 70 alvikite 69 Kajan River, Kalimantan (KAJ) 139 augite syenite 461 kajanite 139, 140 bimodality of in E Africa 67 kakortokite 474, 481-3 breccia 499 kalsilite 32, 36, 44, 104, 109, 127, 135, 136, 149, 166 carbonatite 65, 67, 72 kamafugite 166 ferrocarbonatite 69 kamafugitic rocks 106, 140, 148 gabbro 450, 497 Kamas and Moon Canyon, Utah 120, 142, 144, 148, hypabyssal 464 151,160, 163, 164 ijolite 65, 67, 75, 76 kaolinite 374 Kangerdlugssuaq 499,501 Karoo dolerites 352 leucite lamproite 144 Karoo volcanic cycle 335 phonolite 72 kataphorite 338,411 polyphase 535 katungite 39, 41,45, 136, 165 Prairie Creek 122 Kenya rift 293-309 quartz syenite 426 associations of alkaline igneous rocks 294-6 rhyolite 426 caldera volcanoes 313,314 salic 450, 489 distributions and volcanological characteristics of peralkaline 452 the suites 296-300 s6vite 69 general characteristics of the province 293-4 syenite 497,499 influences of magma chamber processes on Trans-Pecos 422-3 differentiation 306-9 intrusive complexes isotope ratios 305-6 and Cameroon line 274, 277 petrology and geochemistry 301-4 carbonatite 301 basanitic and alkali basaltic suite 301-2 ijolite 301 mixed volcanic associations 303-4 lndex 555

nephelinite-carbonatite suite 301 geochemistry 146-56 transitionally-alkaline series 303 major-elementchemistry 146-9 silicic rocks and caidera volcanoes 313-29 trace-element chemistry 149--52 trace element characterization of volcanic suites intrusive-extrusiveforms 142 and series 304-5 isotopic data 212 Kerguelen Islands 143 kimberlite-lamproite relationship 169-70 Kerguelen-Gaussbergaseismic ridge 137 leucite 97,98,129 Kerimasi (N Tanzania), carbonatite 69, 70, 71 localities and provinces 110-11 kersantite 204 locations in N America 117 khibinite 535 mineralchemistry 156-64 Kidal massif, ring-complex 383-5,387, 389 nomenclature and classification 106-9 Kilauea 230, 241 occurrences of lamproites and other potassic to Kilimanjaro 298,299, 303 ultrapotassic rocks 109-46 Kilombe, syenite nodules 324 olivine 97, 98, 99, 107, 114, 136, 144, 166-7, 198, Kimberley Basin, W Australia 129 166, 167 kimberlite clan 95-100 diamondiferous 129 kimberlite pipes 104 petrogenesis 166-9 kimberlite-lamproiterelationships 169-70 relationships between lamproites, MARID and kimberlite 2, 3, 4, 15, 29, 32, 38-9, 39, 44, 45, 47, 54, other mica-rich xenoliths 170 65, 66, 68, 86, 103-4, 104, 107,109, 120, 124, Sr and Nd isotopic compositions 154 136, 139, 140, 144, 146, 148, 151,156, 166-7, tectonic-geological environment 142-4 191,193, 198,215,284, 539 trace elements 98, 99 definition 95 lamprophyre associations, summary 195 distinguished fromlamproite 97 lamprophyre branches, major petrological contrasts Group I (non-micaceous) 19--20, 25, 96, 99, 170 194 enrichment event 100 lamprophyre clan, hierarchical structure 192 Group II (micaceous) 20, 23, 24, 25, 95-6, 97, 99, lamprophyreversuslamproite 144-5 105, 136, 168, 170 lamprophyre-kimberlite relations 198 chemistry 98 lamprophyres 5, 19, 31, 49, 103-4, 106, 109, 124, 139, source region 100 148, 151,156, 160, 166, 167 relationship with lamproite 97-100 differentiation in 219 relevance to upper-mantle metasomatism 99-100 feldspathic 465 trace elements 98 leucite 136 varieties of 95-7 mafic and felsic enriched relatives 196 King Leopold mobile zone 129, 130 nature and origin of 191-219 Kishalduga (Kenya rift valley) 58 comparative whole rock chemistry 204-12 Kisingiri volcano (W Kenya) 56, 57 criteria for identification of as a clan 193-6 Knox County, Maine 128 discrimination between the four branches 196-8 Kola Peninsula, USSR 72, 163, 531-43 global distribution 215 alkaline ultramafic intrusions 534-5 nomenclature 191,193 crystallization of the agpaitic magmas 539 petrological characteristics (miscellaneous), Gremiakha-Vyrmes 531-3 whole clan 212-15 Khibina apatite deposits 534, 541-3 whole clan mineralogical diagnostic features Khibinacomplex 532, 535 198-204 Lovozerocomplex 532-3,537-9 as parental magmas? 219 volatile components in the alkaline magmas 539- petrogenetic significance 215-19 4l plutonic and volcanic relatives 195-6, 196 Yelet'ozerocomplex 531 as primary-mantle melts 215 Kruidfontein(S Africa) 69 ultrapotassic 133 volatile-poor relatives 195-6 lamprophyres, ultramafic 462-5 labuntsovite 135 lapillae sprays 9 laccoliths 127, 128,421,422 lapilli, autholithic lamproite 124 Lake CargeIIigo Area, N S Wales 131-2, 163 larnite 465 lamproite pipes 167 latite 104, 128, 135 lamproite terminology, historicalsummary 107 laurdalite 437 lamproite 5, 8, 15, 19, 20, 23, 24, 25, 29, 32, 39, 191, lava plateaux 395 195, 196, 198, 200, 202, 203,204, 205, 213, 215, Cameroon and N Nigeria 273 217,218 lavas 64, 120, 136, 142, 298,421 age of emplacement 141-2 alkali 227,230, 232, 239, 242,243,246, 493, 508 controlled by intra-plate tectonic processes 144 alkali basalt 227, 243,491 defined 108-9 alkalic carbonatite 87, 88 diamondiferous 104, 142---4, 151-2, 166 basalt 260, 269, 277, 278 W Australia 97 basanite 127,227,237,280, 491 556 Index

lavas (cont.) leucitetephrite 104 basic 281,282 leucitite 39-44, 107, 128, 138 benmoreite 299, 322 olivine 136, 165 carbonatite 71, 72-3 leucogabbro 361,363, 366, 369,437 composition and evolution of (Ascension Island) leuconorite 368 269 leucorhyolite 436 differing sources 242-3 leucotroctolite 368 emulsified 525 lherzolites, mantle-type 61 fissure-fed 302 LIL elements 36, 57, 133, 260, 262, 284, 285,425, 504 Gardar, distribution and chronology 453-7 depletion in 434 Haiwaiian, trace-elementdata 242-6 enrichment in 39, 166, 167-8, 283,449 hawaiite 234, 260,491 limburgite 135, 140, 296 kamafugitic 135 liquid diatresis 9 lamprophyre 193 liquid fractionation 307, 308, 309, 46l, 468 leucitelamprophyre 137 liquid immiscibility 30, 45, 47, 48, 60, 64, 65-8, 69- leucite-bearing 131 71, 77, 78,214, 301,370 Loihi Seamount 232-3 liquid-fluid distribution processes 485 major-element analyses 232 liquids, unmixing of 64 mafic 301 lithophile elements 2, 7-8 mafic and ultramafic 31 lithosphere 21 mugearite 234 continental 22-3 natrocarbonatite 297 lithosphere focussing 353 nepheline melilitite 237, 243 Loihi Seamount 227, 230, 232, 248 nephelinite 72, 237, 280, 504 isotopic studiesoflavas 241,242 ocean islands, S Atlantic, analyses 256 pre-shield alkalic lavas 243 Oldoinyo Lengai 45, 47, 87, 88, 89, 90, 91, 92, 93 Longonot volcano 315, 322-3 olivine-phyric 491 syn-caldera ash flow 326 phonolite 280, 301-2, 303,465 lopoliths 127 P-phonolite 303 LREE 149 post-erosional 237, 240, 243,246 decline in 301 primitive 237 depletion in 17, 18, 19, 21 rhomb porphyry 303 enrichment in 21, 59, 243,259, 262, 444, 459, 526- rhyolite (peralkaline) 269 7 salic 298, 303,306 Luangwa Graben, Zambia 136 tholeiite 227,230, 243, 506 lujavrite 48,474, 484-5,537, 541 Hawaiian 240 agpaitic 466 tholeiitic basalt 233 eudialyte 537 tholeiitic picrite 233 trachyandesite 519 trachyte 274, 299, 303,309, 465 maars 517 ultramafic 464 macrocrysts 156, 203, 213 layering 475 in kimberlite 95 agpaitic rocks 479-80 olivine 109, 114 Ilimaussaq rocks 473 phlogopite 114 inverted 482 picroilmenite 114 kakortokite, theories of formation 482-3 madupite 39, 108, 122, 164 of magma 476 mafic melt diatresis 8-10 primary 532 mafic rocks 317 rhythmic 537 mafurite 31,32 layers, double-diffusive 482 magma bodies, compositionally stratified 478 Leeward Islands 234 magma chambers 63, 64, 271,329, 330, 478,484, 508, lepidolite 370, 374 511 lepidomelane 387 agpaitic 480 leucite 31, 32, 36, 44, 45, 49, 97, 104, 106, 108, 131, crustal 63,368, 369, 519, 523 136, 137, 138, 139, 146, 149, 160, 164, 166, 167, deep-seated 476 198,202, 213, 345, 351,465, 517 and density hump 308 leucite basalt 107, 140 distribution of minerals 542 leucite basanite 104, 135, 519 Ilmaussaq intrusion 273-4 Leucite Hills, Wyoming 39, 44, 103, 106, 107, 120-2, open 492 124, 141,142, 144, 146, 148, 149, 154, 155-6, pre-caldera 320 160, 163, 164, 165, 167 replenishment of 508 leucite lamproite 97 rupture of 309 leucite lamprophyre 136 shallow 233,234 leucite phonolite 104 smaller homogeneous 525 Index 557

Skaergaard 478 aln6itic 443 stratified 303,452 aluminous (troctolitic) 467 large 525 anchieutectic (multiply saturated) 477 sub-crustal 368 andesitic 34 sub-volcanic 264, 306 asthenospheric 358, 361 trachyte 322 augite syenite 476 zoning within 313 basaltic 34, 315, 322, 330, 362, 363,450, 451,457-8 magma densities 477 anhydrous 466 magma evolution, Menengai volcano 324-5 mantle sources 246 magma and fluid evolution (Ascension Island) 269- basanite 444 71 basic 452, 459, 523,525 magma fractures 23 Gardar 467 magma mixing 63,305,313,315, 329, 331,332, 407, generation of 283-6 423,427, 508, 511,519 petrogenesis of 526-7 back-mixing 309 vesiculated 525 Massif Central volcanism 525-6 benmoreite 322, 461,468 salic magmas 324 residual 450 magma plumbing 59-64 calcitic-dolomitic 92 crustal intrusive processes 63-4 camptonitic 443 pyroxene fractionation 61-3 carbonated nephelinite 86 magma reservoirs 422-3,479 carbonatite 72, 86, 89,450 convecting and slowly cooling 480 possible stylesoforigin 65 oceanic 288 CO2-rich 467 shallow 248-9 comendite 270 magma rise, rate of 93 contaminated 524 magma sources 250 diverse, assimilation of 39 E Greenland alkaline rocks 507, 510 Fe-free K-rich alkaline 165 harzburgite 467 felsic 8, 10, 11,418 lherzolite 41 alkaline 5 lower crustal granulites 467 fractionated 308 spinel lherzolite 467 Gardar, volatile component of 466-7 trace-element constraints 242-6 granite 467 magma storage 235 contamination by sea water 271 magma storage reservoirs 249 halogen-rich 77 magma storage sites 250 hawaiite 450, 451,453,457,461,467,468 magma storage system, evolution of 246, 248-9 high alkalinity 36 magma storage zones 237, 249 high-alumina 450 magmas 277,298,443 troctolitic 461 acid 362, 363 highly-mobile 468 agpaitic 461,467,485 ijolite-urtite 543 crystallization of, Kola Peninsula 539 intratelluric 217 progressive crystallization and formation of K-rich 45 layering in 473-85 genesis of 44 alkali basalt 30, 435,442 kakortokite 481,482 parentalto Gardar rocks 475-6 kimberlite 21, 22, 32, 167, 168, 170, 351 alkali carbonatite 53 differentiation of 167 alkali mafic and ultramafic--background studies lamproite 97, 149, 167, 168, 169 30-4 3-stage evolution model 170 rock systems--the pyrolite model 32-4 lamproite-kamafugitic 167 synthetic systems at low-pressure 30-2 lamprophyre 217-18,450 alkali mafic and ultramafic--recent experimental layered 482, 483 studies 34-44 leucitelamproite 167 alkali olivine basalt 34, 351,444 lujavrite 484 alkali picrite 442, 443,444 mafic 10, 300, 308,426, 437,444 alkalic carbonatite: parental or derivative 85-93 mafurite 32, 40 alternative petrogenetic scheme 91-2 magnesian 282 critique of parental-status scheme 87-9 mantle-derived 30, 441 origin of 89-91 contaminated 412 alkalic/alkaline 21, 22, 273,425,444, 450 interaction with crust 434, 435 genesis of 29-49 mica-peridotite primary 351 interaction with NaCI brine 440 monchiquitic 443 Oldoinyo Lengai type 86 mugearite 461 volatile components in 539-41 Na-rich 44 alkaline basaltic 143 natrocarbonatite 69-71, 77, 78 558 Index magmas (cont.) White Mountainplutons 442 nephelinite 55-9, 66, 67, 70, 74, 77, 88, 92 magmatic foci, migration of, Gardar province 455 carbonated 64 magmatic layering 368 olivine basalt 453,457 magmatic reservoir systems 423 genesis model 467 magmatic systems, time-space evolution of 318 olivinelamproite 167 magmatism 4 olivine melilitite 38 alkaline, Baltic Shield 534 olivine nephelinite 90,93 alkaline mafic 5 olivine s6vite 90, 92, 93 alkaline, tectonic constraints on 361 olivine ugandite 40 anorogenic 366 parental 86, 306, 352, 357,449, 451 effect of late-stage fluids on 370-6 anorthosite complexes 366 and megashears 361 carbonated melanephelinite 301 tectonic and structural controls of 358-70 olivine s6vite 91, 93 within-plate 398 pulaskite 407 basanitic 4 peralkaline granite 475 calc-alkaline 398,427 peralkaline silicic 328 collision-related 395 peralkaline trachyte 328 Cameroon line 282 phlogopite-lamproite 167 carbonatitic, evolution of 65 phonolite 66, 70 cratonic 5 picritic 37, 217 felsic 427 potassic, genesis of, modelled 41 Hawaiian 237 primary 217-8, 354, 468 intra-plate 215, 376, 449 primary syenite 341 lamprophyric, distribution through geological time quartz syenite 428 216 residual 476, 480 Mesozoic, N America 444-5 troctolitic 460 Phanerozoic alkaline 358 volatile-rich 483 plate-margin 215,218 salic 306, 307,451,452, 508 subduction-related 381 alkaline 309 syenitic 493 highly differentiated 461-2 tholeiitic 491,504-5 secondary 510 tholeiitic basalt 444 shoshonite 106 tholeiitic rift 489 silica-undersaturated 440 magnesite 39,44, 166 silicate 68, 91 magnetite 71, 72, 73, 90, 123, 133, 138, 163,405,462, sodic carbonate 86 492 s6vite 75-6 Ti-magnetite 451 sub-silicic 450 magnetite deposits 74 subduction-zonerelated 261,262 Malawi, carbonatitecentres 335 syenitic 351 malchites (semi-lamprophyres) 196 tholeiite 505 Mali (Adrar des Iforas) 381-99 trachybasalt 508 malignite 532, 541 trachyte 324, 331,412, 508 MandaraMountains, Cameroon 278 Trans-Pecos, HFS/LILratios 427 Manengouba, Cameroon 278-9 troctolitic 467 mantle ultramafic alkaline 3 asthenospheric 398-9, 398 ultrapotassic 164 carbonated 443 stable and radiogenic isotope geochemistry 152- depleted 441,443, 527 6 composition of Iforas 393-4 undersaturated 407 enriched 284 volatile-charged, ascent of 320 low-density 353 volatile-rich, Ilmaussaq 478 metasomatized 443 volatile-saturated 481 sub-continental, geochemical evolution of 23 water-saturated 271 mantle composition, primordial 262, 263 wolgidite 165 mantle contamination 23 magmatic activity, within plate 361 mantlediapirism 445,456 magmatic alteration 105-6 mantle enrichment 2 magmatic bimodality 5-6 mantle evolution 169 magmatic centres, migratory 357, 358 mantle heterogeneity 460, 524 magmatic differentiation 148 mantle metasomatism 29, 44-5, 284, 353, 467 magmatic evolution mantle mobilization 394 anorogenic 361-3 mantle pegmatites 170 stages of, Niger anorthositic centres 368-9 mantle plume 241 trend, MonteregianHills 439 mantle processes, importance of 32 Index 559 mantle sources 263, 506 melt channels 7-8 alkaline magmas 273 melt diapirism 10 basaltic magma characteristics 246 melt enrichment 10 convecting upper mantle 285 melt mixing 236 depleted lithospheric 398 melt percolation 7-8, 9, 10 enriched 508 melteigite 120, 534, 535, 541 Fe-rich 460 melting models 442-4 and generation of basic magmas 283-6 melting, large scale 468 isotopic constraints on 239-41 melts lherzolite 29 alkaline 29 for OIBs 255 alkaline ultramafic 7 partial melting of 246 alumino-silicate 542 rare-gas constraints 241-2 anatectic 508,509 similar for oceanic and continental basalts 285 asthenospheric 21 undegassed 232-3 basaltic 260 mantle wedge 354 basanitic 9,16 margins, active and passive 370 carbonate 65, 66 MARID rocks 16 diamondiferous, primary mantle-derived 154 Marquesas Islands 143 felsic 7, 8 Massif Central (France) 58, 517-27 kimberlite 170 chemical and petrographic variation 519 lamproite 168, 170 crustal contamination 523-5 mantle-derived 167 fractional crystallization 520-3 large-percentage 444 geochronology 517-19 mafic, Navajo-Hopi Buttes 127 magma mixing 525-6 mantle 435 petrogenesis of basic magmas 526-7 migration of 7 Mauna Loa 230 mixing with mantle 262 mechanical segregation 369 nephelinitic 16, 38 megacrysts 10, 15, 62-3,154,425-6 phlogopite peridotite 166 alkali feldspar 8 primary-mantle 218 amphibole 8, 278, 521 silica-undersaturated 239 anorthoclase 277,278,426 silicate 23, 66, 78 apatite 426 infiltration of 21 biotite 426 sub-alkaline 324 clinopyroxene 61,277, 278, 282 Menengai 315-16, 319, 324-6, 327 Cr-diopside 218 mercury deposits 426 feldspathic 461 Merrymeeting Lake, geology of 436, 441 garnet 277-8 mesolite 441 ilmenite 278 metacarbonatites (silicocarbonatites) 71 kaersutite 37,426 metamorphic aureoles 436 olivine 129,218 metamorphism 109 orthopyroxene, Al-rich 426 metasediments 128 plagioclase 426, 461,466 metasomatic alteration 351 soda-rich 8 metasomatic aureole 370 spinel 442 metasomatic enrichment 306, 443 Ti-phlogopite 213 metasomatism 6, 10, 72, 74, 78, 85, 165, 167, 168, titanomagnetite 426 337, 349, 354, 445,485,499 zircon 278 acid 370, 374-6 megashear zones 361,381,388 conditions of 2-4 lithospheric 398 definition 1-2 reactivation of 395 development of separate felsic sources 7-10 melanephelinites 55, 57, 60, 61, 62, 63, 68, 90, 279, Fe-Ti 16 295,296, 297, 301,307, 309, 506, 510 gas-phase 217 melanite 109, 305, 338,339, 349,405,465 geological factors 4-5 melaspessartite 196 K-rich 44 melasyenite 405,407, 408, 412 lamproite-source 168 melilite 29, 31, 72, 109, 136, 193, 198, 200, 213,464, large-scale 4 465,492, 517 Na-rich 44 strontian 279 occurrence and distribution 2 melilite nephelinite 68 potash 375 melilitite 3, 5, 8, 29, 30, 32, 37-8, 68,295, 296, 301, potassic 370, 373-4 307, 309, 463,519 sodic 370, 373, 375 olivine 39 ofsub-Kenyan mantle 317-18 melilitolite 492 timing 2 560 Index metasomatism (cont.) tectonic setting 444-5 in the vicinity of Gardar intrusions 465-6 Younger White Mountains and Monteregian Hills metasomatism-modellingexperiments 44-5 435-44 metavolcanic rocks 351 chemistry and isotope geology 438-41 metavolcanics 128 dykes 438 Meugueur-Meugueur ring-dyke 368 geochronology 438 Mg-arfvedsonite 77 Monteregian Hills 6, 436-8 Mg-biotite 387 petrogenesis 441-4 Mg-Mn-spinel 200 Younger White Mountains 435-6 miaroliticcavities 383,418 monticellite 72, 95, 108, 198, 200, 465 miarolitic texture 422 montmorillonite 374 miaskitic sequence 387 monzoanorthosite 363, 369-70 mica 34, 71, 91, 93, 170, 338, 341,370 monzodiorite 434-5,436 green 374 monzogabbro 361,366 mica peridotites 139 monzogranite, porphyritic 388,389 micaschists, eclogitic 381 monzonite 269,433,436, 437,440, 441,503 micro-inclusions, apatites and nephelines 542 hornblende 495 microcline 72, 76, 135, 137, 138, 373, 388,484 layered 495 destruction of 374 quartz 361 microclinization 374 MORB 264 microdiamonds 139 Mulanje complex 352-3 microfoyaites 338, 345,405 peripheral fenitization 341 microgabbro 363 Murcia-Almeria province, SE Spain 124, 132-3, 142, picritic 368 146, 148, 149, 154, 156, 160, 163, 164, 167 microphenocrysts 61,131 muscovite 387 biotite 302 ferroaugite 302 magnetite 73 N American plate 420 titanomagnetite 303 and alkaline magmatism 445 micropulaskite 437 Na-for-K exchange 370 microsyenite 363 NaCI fugacity 540 mid-Atlantic Ridge 269 nahcolite 467 mid-ocean ridge basalts (MORBs) 4, 15, 21-2, 169, Namibia 54 212 nannofossil ooze 264 mid-ocean ridge basalt (MORB) source, depleted 246 narsarsukite 462 migmatites 77, 370 natrocarbonatite 53-4, 67, 69 mineral crystallization, sequence of 34 modes 70 mineral layering 366 Oldoinyo Lengai 47 mineral sorting, vertical 542 parental 69,71-2 mineral stabilities 3, 4, 5, 7 natrocarbonatite magmas 69-71 felsic 10 natrolite 338,484 mineralization 73-4, 450, 465 naujaite 467,474, 477,478,479, 480, 484 mineralizing fluids 78 naujakasite 484 minette 49, 104, 105, 124, 127, 128,132, 133, 135, Navajo-HopiButtes, Arizona 127, 146 139, 140, 144, 146, 148, 149, 163, 165, 166, 193, Nb depletion 132 195, 196, 198,212 143Nd/14*Nd ratios 16-25 missourite 107, 127 nepheline 30, 34, 36, 37, 48, 49, 109, 136, 149, 202, mixing processes 263-4 279, 301,338, 339,405,408,416, 440, 479, 481, mixing, magmas and crustal material 441 482, 484, 534, 535, 541,542 Mn-ilmenite 131 nepheline hawaiite 504 mobile belts, Pan African 360, 361 nepheline syenite-porphyries 535 molybdenite 405 nepheline syenite 66, 68, 107, 123, 138,215, 296, 306, molybdenum deposits 426, 502 336, 337, 341-4, 417-19, 425,437, 440, 466-7, monazite 71,109, 168 502, 531,535 Th-rich 373 miaskitic 537 monchiquite 128, 198,212, 218, 219, 442, 463,464, peraluminouspotassic 127 495 nephelinite magma 55-9 picritic 196 nephelinite-carbonatitecomplexes 54-79 Mongolowe complex 336 nephelinite 3, 5, 6, 8, 15, 29, 30, 32, 36-7, 68, 90, 196, nepheline syenite and syenite 338, 341-4, 345,347, 273,294, 295,296, 300, 303, 304, 307, 336, 337, 351 339, 349, 351,352, 354, 504, 506, 517, 519 nepheline syenites 341 analyses 58--9 Monteregian Hills and White Mountains and carbonatite 53-79 Older White Mountains 433-5 immiscible with alkalic carbonatite lava 87 Index 56I

melanephelinite 349 Ojin Seamount 230 nosean leucite 279 Oka carbonatite complex 436, 440, 441 olivine 39,297, 349 Oku, Mt., Cameroon 278 olivine-poor 55-8, 59-60, 61, 62 Oldoinyo Lengai 45, 47, 66, 67, 90, 92, 93, 296 olivine-rich 37-8, 58, 59, 62 eruptions of 86, 87, 297 world average 58 natrocarbonatites 69, 70 net-veining 418 oligoclase 133,404 New England Seamounts chain 444 olivine 30-1, 32, 34, 35, 36, 38, 40, 44, 45, 61, 71, 72, Ngaound+r6 Plateau, Cameroon 278 95, 107, 114, 123, 129, 131,133, 136, 137, 139, Niger-Nigerian alkaline ring complexes 357-77 148, 149, 156, 164, 165, 167, 196, 200, 234, 258, effect of late-stage fluids on anorogenic magmatism 282, 301,349, 364, 365, 368, 369, 370, 425,437, 370-6 465,520 tectonic and structural controls of anorogenic carbonatite 90 magmatism 358-70 cumulus 436-7 Niggli values 106 fayalitic 420, 451,475 Nkalonjecarbonatitecentre 353 stabilized by H20 37 nodules 5, 8, 45 olivine basalts 294, 298 amphibole 10 olivine gabbro 531 diamond 218 olivine lamproite 99, 107, 114, 136, 144, 166, 167, 198 gabbro 6, 320-1 olivine leucitite 136, 165 harzburgite 493 olivine melilitite 39 kaersutite eclogite 36-7 olivine nephelinite 39, 68, 349 kimberlite 4 olivine tholeiite 280 kimberlite peridotite 4-5 olivine ugandite 39 lherzolite 37, 45, 59 olivine-glimmerite 107 mantle 2, 64 olivinites 67, 534 mantle peridotite 218 Olorgesailie 300 peralkaline granite 6 eruptive sequence 303-4 peridotite 6, 7 Oman Mountains, Arabia 106 phlogopite-clinopyroxene 45 ophiolites 360, 381 plutonic 313, 318, 320, 323 Orciatico, Pisa, Italy 133 pyroxenite 45 ore deposits, Nigeria 376 sanidine-coesite eclogite 7 ore metals, development of important economic spinellherzolite 9, 35 sources 375 spinelperidotite 10 orendite 39, 40, 41,103, 106, 107, 108, 120, 121-2, syenite 6, 320, 324 164 transformed 4 orogenesis, collisional 143 ultramafic 2, 3, 4, 5, 9 orogeny 360 nontronite 109, 164 orthoclase 72,76,149 noonkanbahite see shcherbakovite orthoclase effect 387 nordmarkite 361,405,437, 439,499, 502, 503 orthopyroxene 32, 34, 35, 36, 41, 44, 45, 149, 156, nosean 109 164, 165, 167, 202, 258, 388,425-6 nyerereite 53-4, 69, 70, 464 stabilized by CO2 37 Nyos, Lake, Cameroon 278 Ossipee ring complex 435-6, 442 oxidation 484 obduction 360 oxides Obontorok ring-complex 367 Fe-Ti 131,133, 138, 139, 324, 361,370, 383, 387, obsidian 303, 320, 328 388,465, 520 comenditic 269-70 crystallization of 323 rhyolitic 316 Fe-Ti-Cr-Mg-A1 163 ocean basins, isotopic data 16-18 iron 73, 77 ocean crust, subduction of 262, 264 K-Fe-Ti-Ba 163 ocean island basalt (OIB) 15, 21-2 precipitation of 56-7 alteration 255,257 oxygen fugacity 68, 73, 97, 233,477 chemically anomalous, hypotheses for origin of oxygen isotopic studies 154-5,271 253 geochemistry 255-61 Pagalu (Annobon) 282 major elements 255 pahoehoe surfaces 454 source characteristics 258-61 Paka, Kenya 314, 315, 318,321-2 trace elements 255 palagonite 142, 232 ocelli 202-3, 213,214, 219 Pamir, Mongolia, USSR 140 ocellitextures, syenites 45 Pan-African magmatic evolution, proposed model, the odinite 196 Iforas 396-7 Ofoud ring complex 363-4, 366 Pan-African orogeny 357, 358, 360-1,388-9 562 Index pantellerite 6, 326, 331,423 isotopic variability 16, 18 phase equilibrium studies, central Kenya 320 mica 122, 139,463,464 paragneisses 326 micaceous, diamond-bearing 104 pargasite 169, 412 phlogopite 166 ferro-pargasite 451 spinel 517 ferroan 410 univariant melting 44 titanian 202 peridotite massifs 2 parisite 71 perknites 108 partial melting 6, 20, 30, 33-4, 39, 44, 45, 104, 164, perovskite 61, 71, 97, 108, 114, 116, 122, 123, 129, 167, 169, 170, 242, 255,257-8,259, 261,306, 131,133, 139, 164, 198, 301,305,409, 465 313, 354, 361,425,443 perpotassicrocks 105 alkalineultrabasic silicate 65 perthite 337, 383, 386, 387 amphibole peridotite 38 perthosites 338 of asthenosphere 64 oversaturated 342 clinopyroxenite 165 phenocrysts 61,108, 144, 146, 160, 269, 338,405,410 garnet lherzolite source (Honolulu Group) 243 aenigmatite 417 granites and gneisses, upper-crustal 524 alkali feldspar 302, 326 granulitic material 441 amphibole 193, 339, 417 harzburgite 170 kaersutitic 417 lherzolite 36, 39, 167 analcime 48 Fe-rich 34 ankerite 139 Mg-rich 34 anorthoclase 322, 417, 421 LILE-rich streaks 285 apatite 72, 139, 417 ofmafic lower continental crust 323,331 augite 138, 301,339, 404, 421 mantle 165, 166, 246, 354, 460, 517 biotite 193 metasomatized 323,526 calcite 69-70 metasomatized spinellherzolite mantle 444 chrome-spinel 139 N-MORB source mantle 263 clinopyroxene 55,417 olivine pyroxenite 39 diopside 114, 131,138 peridotitemantle 39, 65, 165, 167 fayalite 421 primitive mantle 263 manganoan 417 pyrolite 38 feldspar 298,324 refractory mantle 167 fractionation of 304 small percentage 241,243, 284, 468 gregoryite 70 MORB source 286 hedenbergite 326 spinel lherzolite 444 hornblende 288 sub-continentallithosphere 170 K-richterite 114 subductedocean crust 262 leucite 129, 138 upper mantle 394 magnetite 72-3 of wall-rocks 243 microcline 388 partial melts, mixing of 243 nepheline 301,302, 324, 417 partially molten zones 319-20 nyerereite 70 PAWMS (Pacific authigenic weighted mean olivine 114, 120, 123, 131,138,301,339,417,459 sediment) 263-4 orthopyroxene 422, 521 Pb isotopic data, Hawaiian volcanism 241 perthite 404 Pbisotopic studies 155-6 perthitic feldspar 128, 337 pegmatite 450, 501,527 phlogopite 120, 131,135, 138, 139, 165 Ivigtut 466 pigeonite 521 layers 479-80 plagioclase 196, 303, 404, 417,460 marginal 475 pseudoleucite 114 minerals 467 pyroxene 62, 63,301,339 veins 483 quartz 320, 421 pegmatitic-hydrothermal trend 389 resorbed 139, 217 pelagic sediments 263,264, 265 sodalite 417 Pendennis, Cornwall, UK 132, 133, 149, 160 Ti-phlogopite 114 peralkaline rocks 104, 149 titanaugite 417 peralkaline volcanic rocks, Menengai 328-9 titanomagnetite 417 peralkalinity 316, 317, 324, 326, 339, 343, 345,352, zoned 313 417,421 phlogopite 2, 3, 5, 7, 9, 31, 39, 40, 41, 44, 45, 49, 72, percolation, melt 7-8 76, 77, 97, 108, 109, 123, 127, 129, 131,132, periclase 71 133, 135, 136, 138, 139, 148, 160, 162, 165, 167, peridotite 7, 15, 108,368, 531,534 218, 243, 258,468 biotite 464 Ba-Ti-phlogopite 198 garnet-bearing 237 biotite-phlogopite 193 Index 563

primary 32 lamproite 114, 142 tetraferriphlogopite 139, 160, 202 mafictoultramafic 439 Ti-phlogopite 114, 123, 131,138, 160, 198 peralkalinegranite 335,433 phlogopite peridotite 166 post-tectonic 398 phlogopite-biotite 91 pyroxenite 433 phonolite 5, 6, 15, 37, 55-6, 60, 61, 63, 66, 77, 107, quartz syenite 422 128, 234, 273,278,281,286, 293,294, 301,302, ring 403 305, 306, 335,351,417-19, 425,452, 454, 517, syenite 6, 325 521 syenogranite 388-9 agpaitic 468, 538 ultramafic 106 G-phonolites 295, 301,304, 307, 309 Velasco 403 LREE depleted 305 Younger White Mountains and Monteregian Hills immiscible with alkalic carbonatite lava 87 435-44 P-phonolites 296, 297-8, 300, 301,309 zoned 6 LREE enriched 305 pneumatolytic-hydrothermal processes 374 peralkaline 349,424 Pniel, Postmasburg, Swartruggens etc., S Africa 136 phosphate ore deposits 541 Pollen (N Norway) 71 picrite 495,504, 506 polymerization 66 alkali 442 polyvalent cations 37 tholeiitic 33,510 porphyries 196, 389 picroilmenite 96 hydrothermal alteration 370 pigeonite 34, 35, 422 quartz 495 pillow dykes 499, 504, 508 porphyrites 196 pillow lavas 232 potassic-ultrapotassic rock suites compositionally pillows, diorite 499 related to lamproites 112-13 piperno 124, 142 potassic-ultrapotassicrocks 127, 140 plagioclase 7, 30, 31, 66, 107, 109, 135, 136, 202, 234, potassium 30 317, 363, 365, 368,416, 437,460, 491,520 Prairie Creek see Crater of Diamonds calcic 420 precipitation sodic 339, 386, 426, 458 of augite 61 zoned 369 of olivine 61, 64, 72 plagioclase effect 324, 329, 387 primary magmatic 74 plagioclase fractionation 260, 301,304, 307, 412, 521 of apatite 72 plate motion 55 pressure release 361 plate movements, directional changes 283, 361 pressure-release melting 444 plateaubasalts 277, 504 priderite 108, 114, 122, 123, 128, 129, 135, 163, 165, tholeiitic 495, 504 200, 203 plateau lavas 383 Priestly Peak, Antarctica 138, 142, 156, 160 Pliny Range, geology of 434 Principe, Gulf of Guinea 280 plugs 129, 132, 193,337 protolithionite 374 biotite granite 499 provinces (alkaline) diorite 498 Angola 54 diorite-gabbro 436 Appalachian 337-8 granite 436, 495 carbonatite 198 lamproite 124 E Africa 54, 55, 59 leucite lamproite 142 E Siberian 54 monzonite 436 Gardar, S Greenland 449-68 trachyte 282 Iforas 381-99 tristanite 282 Karoo 57-8 plume Kenya 293-309 ascending 168 MonteregianHills 219,433-45 deep mantle 282, 285 N Chilwa, petrochemistry 335-54 source, degassed 241 Niger-Nigeria 357-8 plutonic complexes, sub-volcanic 64 Roman 107, 108, 135, 155, 163, 165 plutonism Tadhak, Permian 383, 398 basic to salic 491 Velasco, petrology, chemistry and crystallization granitic 218 history 403-12 Kangerdlugssuaq district 498-501 White Mountains 433-45 plutons 64, 127, 129,219, 382, 405 provinces (ultra-alkaline), Kola 67 Adma 388 provinces (ultrapotassic), Toro-Ankole 135, 136 carbonatite 78, 163 prowersite 103 durbachitic 135 pseudobrookite 120, 122, 123 granite 422 ferro-pseudobrookite 163 ijolite 74-5 pseudoleucite 29, 48, 120, 138,203 564 Index pseudomorphs 69-70, 138, 139, 337 in lamprophyres 212 carbonate 464 REE data, Trans-Pecos 425 pulaskite 338, 342, 343,405,407,408,409,410, 437, REE distribution, Oldoinyo Lengai lavas 87, 88 451,475,478,499, 502, 508,531 REE fractionation 258 differentiation of 412 REE minerals 69, 73-4 pyrite 114, 337, 338,462 REE partitioning 71 pyrochlore 71, 72, 73, 337, 370, 376 REE patterns, Hawaiian alkalic lavas 242, 244-5 pyroclastic units, zonation in 325-6 regional uplift 282 pyroclastics 193 replenishment processes 508 trachyandesite 519 residua pyrolite 34 differentiated 331 pyrope 166 silica-oversaturated 439 Cr-pyrope 122, 164 silica-undersaturated 440, 408 pyroxene 55, 57, 61, 72, 74-5, 137, 193, 301,338, 339, upward migration 476 349, 386, 405,409-11,412, 520, 542, 543 residuasystem 286-7,407 alkali 409 residual fluids 370 hedenbergitic 337 boiling of 373 omphacitic 44 resorption 61, 62, 72, 108 reverse zoning 63, 64 fractional 166 secondary formation 465-6 rheomorphism 351 Ti-rich 198 rhomb porphyry 302 pyroxene cores (green) 63, 64 rhyodacite 233 pyroxene fractionation 61-3,351 rhyolite 6, 68, 104, 105, 274, 278, 279, 286, 287, 299, pyroxene zoning 410, 411 303, 307, 315, 323,382, 383, 389, 398, 421-2, pyroxenite 16-17, 25, 77, 86, 436, 437, 517, 531,534 426, 508, 509, 517, 519, 523, 524 alkali 61,502 alkali 273,294, 296, 298, 303,309,425 biotite 137,464 ignimbritic 362 cumulative 63 leucorhyolite 436 mica 463,464 metaluminous 422,424, 425,428 origin of Massif Central 521 peralkaline 303, 313,423,424, 425,428,434, 468 quartz 49, 71,108, 123, 132, 133, 137, 138, 149, 163, rhythmic layering 364 164, 166, 217, 337, 339, 342, 374, 375, 383,388, richterite 97, 135, 383, 387 416, 437 K-richterite 114, 120, 123, 129, 132, 133, 138, 170 quartz diorite 360 zoned grains 160 quartz mangerite 449 K-Ti-richterite 108, 156, 200, 202 quartzmonzonite 361,434 Ti-richterite 131 quartz porphyry 370, 495,508 richterite-arfvedsonite 135 quartz syenite 269, 336, 337, 339, 341,361,383, 386, riebeckite 337, 338, 387,405 405,407, 419-21,422, 426, 433,451,495, 503 riebeckite-arfvedsonite 133 quartz trachyte 278, 279, 282, 286, 419-21,423,439, rift valleys, continental, isotopic data 18-19 425 rifting 505 quartzite 360 E Africa 6, 136, 293-4, 335 fenitized 77 intra-continental 449 quench crystals 138 SAmerica-Africaplate 403 quench textures 525 within plates 361 ring complexes 382 Iforas, oversaturated alkaline 381-99 radiogenic heat 169 Niger-Nigeria 357-77 rare gases, isotopic analyses of 241-2 rischorrites 535 rasvumite 200 rock-fluid interactions 370, 375-6 Rb depletion 16, 17, 18, 19 Rodberg iron deposit (Fen, S Norway) 74 Rb enrichment 17-18 Roman co-magmatic province 107, 108, 135, 155, reaction rims 55, 61 163, 165 recrystallization roof collapse 484-5 partial 388 rosenbuschite 424 secondary 338, 387 Ruri Hills (W Kenya) 69 Red Hill complex 435 rutile 97, 132, 133, 135, 138, 139, 165, 168, 170 reducing conditions 539 REE depletion 160, 521 St Helena 253-61 enrichment 53, 78, 217, 316, 391-2, 405, 439, 440, salic rocks 303 484 fractional crystallization origin 323 inlamproites 149 incompatible trace-element enriched 304 Index 565

origin of 286-9 SO2 fugacity 541 under- and over saturation 287 sodalite 48, 109, 202, 301,338, 343, 344, 345,437, salite 156 440, 466-7,477, 479, 480, 484, 540 sandstone 280 upward-migrating crystals 479 sanidine 41, 44, 49, 104, 108, 114, 120, 123, 131,132, sodalite foyaite 478,479 133, 135, 137, 138, 160, 163, 165-6, 234 sodalite syenite 538 sanidine trachyte 234 sodic peralkaline trend, Iforas rocks 387 Sgo Tom6, Gulf of Guinea 280-2 Sokli carbonatite (N Finland) 75 sapphire 124 sorting, by convection currents 478 scapolite 198 source characteristics, ocean island, S Atlantic 258- schists 360 61 schlieren 74, 219 source reservoirs, potential for OIBs, constraints on disrupted 72 261 scoria cones 131 s6vite 53, 71, 72, 73, 75, 76, 77, 78, 90, 339, 436, 463, sea-floor spreading 381,489-90, 505 465 seawater 271 s6vsbergite 337 sediments spessartite 204, 212 pelagic 263,264, 265 sphalerite 375, 376, 462 terrigenous 263 sphene 61, 71,108, 109, 131,133, 135, 137, 138, 164, selagite 107, 133 166, 168, 301,305,338, 369, 383,387, 388,405, sequential tapping 452 408,498, 541 sericite 339, 374 sphene fractionation 521 serpentine 114, 123, 132, 164 spinel 3, 41, 45, 97, 108, 116, 122, 129, 133, 136, 163, serpentinization 167 203-4, 205, 425 Seward Peninsula, Alaska 127 Cr-spinel 114, 123, 132 Shaki and Okeho, SW Nigeria 137 Mg-Mn-spinel 200 shales 280 Zn-spinel 198 shcherbakovite 108, 129, 164, 200 spinel lherzolite 524 shear forces 306 spinelperidotite 2, 16-17, 517 shear zones 360, 361,382 Spotted Fawn Creek, Yukon 128 lithospheric, reactivation of 361 Sr-barite 122 Pan-African 357, 361,376 Srednogorie 135 shonkinite 104, 107, 124, 127, 138, 140, 144 87Sr/S6Sr isotopic ratios 16-25, 63 shoshonite 106, 142, 144, 166 mantle and crustal types 15 siderite 462, 467 steenstrupine 484 siderophyllite 370, 373, 374 stilpnomelane 387 sidewall crystallization 313, 451,476 stocks 193,382 Sierra Nevada, California 127, 155-6 diorite 434-5 Silali 314, 315-6, 318 syenite 434-5 faults and fissures 320 stoping 451,452, 461,508 nodules 320, 321,323, 330-1 and emplacement of Ilimaussaq intrusion 475 silica 45 strato-volcanoes 60 silica enrichment 34, 44, 132 stress fields, within-plate 361 silica saturation 39, 40, 41, 42, 122, 167, 303, 345, subduction 15, 144, 253, 264, 360, 381,394, 395,427 349, 416, 420, 427, 437 andcalc-alkalinemagmatism 398 silicate melts, infiltration of 20 of oceanic crust, chemical modification during 262 silicic rocks of Kenya 313-32 subduction zones 360 basalt-trachyte relationships 320-3 subsidence 384, 385 the caldera volcanoes 314-15 Suiko Seamount 230 generalized models 329-32 sulphates 193 geological evidence for depths of magmatic sulphur fugacity 477 differentiation 318-20 Sunnfjord, W Norway 135 rock types 315-18 Suswa 313, 315-16, 319 trachyte-trachyte and trachyte-rhyolite syenite plutons 6 relationships 323-9 syenite porphyries 128 silicification 74 syenite 68, 104, 105,273, 324, 337, 339, 341-4, 346, sills 129, 132, 193, 236, 503 351,352, 363,387, 434, 435-437,451,466, 498, lamproite 114, 142 502, 503, 531,537 mafic 422, 426 agpaitic 452, 492 stacked 422 agpaitic nepheline 474 Sisco, Corsica, France 133, 134, 135, 142, 149, 163 alkali 108,433,532, 535 slab, down-going 169 augite 451,452, 474, 499 Smoky Butte, Montana 123-4, 127, 142, 144, 146, biotite-aegirinenepheline 531-2 149, 154, 155-6, 160, 163 of crustal origin 440 566 Index syenite (cont.) thorium 376 differentiation of 341 Thornton-Tuttle differentiation index 416, 422 Emuruangogolak 318 Ti-Al-augite 61 ferrosyenite 368 Ti-amphibole 198 hastingsite quartz 434 Ti-diopside 114 Klokken, layeringin 483 Ti-K-richterite 202 laminated 451 Ti-magnetite 451 nepheline 66, 68, 107, 123, 138, 215,296, 306, 336, Ti-Mg-chromite 131 337, 341-4, 417-19,425, 437,440, 466-7, 502, Ti-phlogopite 123, 131,138, 198 531,535 Ti-pyroxenes 198 miaskitic 537 Ti-richterite 131 peraluminous potassic 127 Ti-Zr-garnet 200 nepheline-sodalite 435 Timedjelalen ring complex 385-6, 387, 389 quartz 269, 336, 337, 351,361,383,386, 405, 407, tin mineralization 398-9 419-21,422, 425,433,451,495, 503 Tinderet (Kenya) 70, 297 rare-earthmelasyenites 412 tinguaites 128,437,499 sodalite 538 TiO2 depletion 132 ultrapotassic 137 TiO2 enrichment and depletion 149 syenitic fenites 78 titanaugite 336-7 generated by carbonatite 75-7 titanomagnetite 57, 116, 138, 234, 364, 365,405,425, generated by ijolite 74-5 475,479, 541 syenogabbros 502 tonalite 388 sylvine 467 topaz 370, 374 symplektite, quartz feldspar 388 Toro-Ankole and Birunga volcanic field, Uganda 136, 143, 155-6, 163, 165, 168 trace elements 90 lamprophyres 205, 207-12 Taguei anorthositic complex 369-70 OIBs 254-5,257-61 Takellout ring complex 389 trace elements, incompatible 258, 261,263, 321 talc 136 abundances 238, 305,315 Tanzania, isotopic data 19 correlation with peralkalinity 317-18 tchevkinite 387 enrichment in 236, 253, 299 tephra 132, 137 trace-element abundances 151 Laacher See, zoned 305 trace-element chemistry, lamproites 149-52 tephrites 140,294, 296, 301,302, 307,517 trace-element data, Hawaiianlavas 242-6 Terceira rift 11 trace-element enrichment 19, 90-1,167 terrigenous sediments 263 trace-element geochemistry, Trans-Pecos province tetraferriphlogopite 139, 160, 202 439-41 Texas, Trans-Pecos Province 415-28 trace-element partitioning 30 early work 415-16 trace-element signatures 58-9, 60, 370, 374 field relations 422-3 trachyandesite 419,454, 504, 517, 523, 525 igneous rock types 416-22 evolution of 520-1 isotope geochemistry 425 trachybasalt 315,419,454 location and extent 425 trachyphonolite 63,278,294, 296, 300, 303, 304, 309 megacrysts and mantle-derivedxenoliths 425-6 LREE enriched 305 mineralization 426 trachyte 5, 6, 7, 11,104, 105, 108, 135, 234, 243,255, relations between tectonic setting and 273, 278, 279, 280, 281,287, 294, 296, 298, 303, magmatism 426-7 304, 305,307, 309, 315,318,320, 323, 326, 331, structure 426 351,408, 417-19, 426, 434, 444, 452, 454, 495, trace element geochemistry 423-5 517, 521,523 texturelampropyres 193 alkali 107 Th, as general index offractionation 258 anorthoclase 234 thermal anomaly 7, 361 peralkaline 278,299, 313, 322 thermal aureole 72 phase equilibrium studies, central Kenya 320 thermal contraction 308 porphyritic 403,404-5 thermal divide 412 quartz 278, 279,282, 286, 419-21,423,425 low-pressure 287-8 sanidine 234 thermodiffusion 316, 461,540 trachyte-trachyte mixing 324 tholeiite 232, 243,493,504 'trap door intrusions' 422 Fe-Ti 504-5 tremolite 109 K-rich 495 Tristanda Cunha 143, 253-61 olivine 280 tristanite 280 potassic 493, 508 trough banding 482 tholeiitic shield-building 227-8,233-4 Tuareg shield 360, 362, 369, 381,388,398 Index 567

tufts 123, 129, 136, 144 volatile complexing 313,326, 328, 329, 330, 331-2 agglutinate 142 volatile components air-fall 315, 325 accumulation of 479, 480, 540 ash-flow 299, 303,307, 308, 309, 315,320, 426 acid 539-40 brecciated and welded 403 alkaline magmas 539-41 carbonate 297 C-rich 467 hydrothermally altered 404 dissolved 476-7 nephelinite, ScoresbySund 493 volatile content, and nephelinite magmas 60-1 phonolitic 305 volatile degassing 305, 317 post-caldera 331 volatile elements 232 pre-caldera, Menengai 324 volatile enrichment 218,481 sandy 131 volatile flux 7, 9, 10 welded agglutinate 124 volatile fugacities, lamprophyre melts 198 Tundulu complex 353 volatile loss 32, 308,483,484 Turkanadepression 297, 301 volatile phase 323 Two Buttes, Colorado 128 volatile pressure release 482 volatile release 354 volatile saturation 308 ugandite 31, 32, 140 volatile-phase transfer 167, 170, 321,461 biotite 165 volatiles 4, 7, 34, 37, 40-1, 72, 73,325 olivine 39 channelling of 361 ultramafic lamprophyre branch 196, 198,200, 202, and genesis and evolution of magmas 29 203,204, 205, 212, 213,214, 217, 218 influx of 444 ultrapotassic and perpotassic rocks 129, 148 residual 8 ultrapotassic and potassic rocks, Sr and Nd isotopic upward concentration of 478 compositions 155 volcanic migration 237 ultrapotassic rocks 103-4, 106, 107-8, 154, 155 volcanic rocks univariant melting 44 basic (Cameroon line), analyses of 275 uplift 144, 361,382, 418 intermediate and evolved (Cameroon line), analyses epeirogenic 54-5 of 276 upwelling 22, 25 volcanic rocks, Trans-Pecos 423 uranium 363, 376, 426 volcanics uranium deposits 485 mafic 8 urtite 66, 67, 68, 532, 534, 535,537, 541,543 potassic 135-6 Usaki complex (E Africa) 67 shoshonitic 140 ussingite 484 volcanism alkaline, Cameroon line 273 alternatingmafic-felsic 6, 10-11 vapour phase 352 anorogenic, within-plate 358 buffering by 317 bimodal, basalt-trachyte 297 halogen-bearing 321 Biu Plateau 277 halogen-rich 328 central, Kavirondorift 294 vapour pressure, variation in 509 dispersed, Massif Central 518 vapour-phase transfer 167 fissural 388 vapour-phase transport 313, 329, 331-2, 345, 347-8 intra-plate 273, 284 varioles 213 K-rich 144 Velasco alkaline province (E Bolivia), petrology of nephelinitic 61 403-12 oceanic 273 petrogenesis 411-12 Pan-African domains 361 pyroxene and amphibole relations in the parasitic 303 undersaturatedrocks 409-11 volcanoes rock chemistry 405-9 bimodal 294 verite 103, 108, 132 caldera 313, 314-15 vesicular texture 422 basalt-trachyte 294 vesiculation 233,525 bimodal, Emuruangogolak 305,306 villiaumite 466,484, 540 Quaternary 299, 303, 305 viscosity trachytic 303 decrease in 307 central 518 high 322 nephelinite-carbonatite association (Kenya) increase in 9 296-7 lowering of 450 central, mixed 295,296, 298,299-300 unusually low, related to F content 466 Kilimanjaro 299, 303 vlasovite 269 Mount Kenya 299, 303 volatile accumulation 484 Olorgesailie 300, 303-4 568 Index volcanoes (cont.) crustal 212, 218,250, 523 composite, Mount Cameroon 279 cumulate 237 felsic 11 gabbroic 235 fissure 518 dunite 130, 167,236,237,242, 249 peralkaline 320 mineral chemistry of 233 shield 423,495 feldspathic 461 basalt-trachyte 294, 309 gabbro 249 basaltic 298 garnetlherzolite 109 bimodal 303 glimmerite 170, 465 limburgite and nephelinite 302 granite 269 granulite 116, 287 harzburgite 116, 130, 167, 169 W Africa, geological map 274 Hawaiian, distribution of 249 W African craton 360, 381,388, 398 kimberlite 168, 169 W Kimberleys, W Australia 39, 124, 129-30, 142, lamproite 123 144, 146, 148, 149, 154, 156, 160, 163, 164, 165, Leucite Hills 122 167, 168 lherzolite 116, 169, 233, 249-50 wadeite 108, 122, 123, 129, 163-4, 198, 200 mantle-derived 213, 237,425-6, 524 wall-rock metasomatism 450 mantle peridotite 202 wall-rock reaction 89, 92, 284, 460 MARID 169, 170 Walvis Ridge 263 melasyenite 135 Wasaki complex (E Africa) 67 metasomatized 100, 170, 284 water saturation 92, 93 metasomatism of 169 water vapour, partial pressure of 288 olivine cumulates 233 wehrlite 40, 460 olivine-rich 130 Wilson cycle 55 peridotite 160, 167, 170, 277, 278, 279, 282 Pan-African 397 phlogopite-pyroxenite 163 Pan-African Trans-Saharanorogenic belt 398 plutonic, composition and evolution of (Ascension Winnett alnoite sill 127 Island) 269 wolframite 376 Precambrian rocks 425 wolgidite 39, 40, 41,108, 164, 165 pyroxenite 109 wollastonite 339, 349,465 spinellherzolite 109, 237, 249, 527 wyomingite 103, 107, 108, 120, 121,133, 136, 164, ultramafic 23,233,425,465 165 wehrlite 235, 236, 249 xenocrysts 95, 109, 164, 195 yamaskite 437 Cr-diopside 61 K-feldspar 388 kimberlite 167 zeolites 109, 132, 163, 164, 193, 324, 338, 339, 349 olivine 233 zinnwaldite 370, 373,374 plagioclase 368 zircon 71,109, 133, 138, 164, 166, 168, 337, 338, 369, xenoliths 3, 71, 95, 109, 154, 195,218,337,403,465, 376, 383, 387, 388,405,420, 424, 521 495, 542 Zn-Mg-chromite 204 anorthositic 461,466 Zn-nordite 462 Ascension Island 269-71 Zomba-Malosa complex 336, 339, 341,343, 345, 351 basalt 303 granite, quartz syenite and syenite 337, 352 basic 383 zone of melting, ascent of 309 biotitite 109 zone refining 166, 284, 306 biotite-clinopyroxenite 109 zoning 160 COz-rich inclusions 233 of magmas 476 cognate 156, 282 Zr/Ti, as index of fractionation 57 cognate and accidental 138 Zr, as index of fractionation 288