Precambrian Geology of Finland (eBook)

Martti Lehtinen, Pekka A. Nurmi, O.T. Ramo (Autoren)

eBook Download: PDF

2005 | 1. Auflage
750 Seiten
Elsevier Science (Verlag)
978-0-08-045759-8 (ISBN)

Infos

Focusing on the Precambrian in the central part of the Fennoscandian Shield, the book combines the results from modern geological and geophysical research into a detailed petrologic, lithologic, and structural synthesis and interpretation of the Archean and Proterozoic of Finland. It will be of value to anyone interested in the evolution of the shield in particular and in Precambrian geology in general.

Inhalt

Cover 1
Table of contents 6
Preface 14
Overview 16
Location, subdivision, timing, and general charateristics 19
Regional geographic nomenclature 22
The Archean bedrock 28
Faulting of Archean crust and emplace -ment of Paleoproterozoic cover rocks 28
The Svecofennian bedrock 28
Rapakivi magmatism and the Jotnianperiod 30
The Vendian period and the Paleozoic era 30
Late events affecting the bedrock 31
Archean rocks 34
Introduction to the Archean of Finland 37
The extent of the Archean inFinland 37
Classifying and subdividing theClassifying and subdividing the 41
The Karelian domain in eastern Finland 43
Ilomantsi terrain 43
Hattu supracrustal belt 44
Kovero supracrustal belt 51
Nunnanlahti and Ipatti supra-crustal belts 51
Lieksa complex – granitoids and high-grade gneisses 52
Granitoids intruding the Hattu and Kovero supracrustal rocks 53
Kianta terrain 55
Suomussalmi greenstone belt 58
Kuhmo greenstone belt 59
Tipasjärvi greenstone belt 62
Granitoids, gneisses, and crustal evolution in the Kianta terrain 63
Nurmes gneiss complex 67
Iisalmi terrain 68
Proterozoic reworking and theboundaries of the Iisalmi terrain 68
Origin of the present metamorphic Zonation pattern 71
Varpaisjärvi granulite complex 72
Rautavaara complex 73
Ranua terrain 74
Oijärvi greenstone belt 75
Siurua granulite complex 75
The Karelian domain in northernFinland 76
Koillismaa terrain 77
Napapiiri terrain 77
Suomu terrain 78
Tuntsa terrain 79
Granitoid complexes 80
Tuntsa and Tulppio supracrustalbelts 83
Pomokaira terrain 83
Muonio terrain 84
Ropi terrain 84
The Kola domain in Finland 85
Inari terrain 86
Sørvaranger terrain 86
Insights into the deeper Archean crustin Finland 88
Exhumed deep crustal sections inFinland? 88
Distribution and composition ofburied Archean crust 90
Xenoliths and deep seismicstudies 91
Discussion and synthesis 93
Archean thermal regimes andtectonic consequences 93
Regional scenarios and correlations 96
Comparisons and contrastsbetween Archean and Svecofenniancrustal processes 98
Layered mafi c intrusions of theTornio–Näränkävaara belt 116
Introduction 119
Geologic setting of the Tornio–Närän -kävaara belt 119
Cumulus sequences 121
General characteristics 121
Kemi intrusion 121
Penikat intrusion 123
Portimo layered igneous complex 126
Koillismaa layered igneouscomplex 129
Parental magmas and isotope studies 133
Parental magmas 133
Isotope studies 135
Mineral deposits 135
Ore types 135
Kemi chromite deposit 137
Mustavaara Fe-Ti-V oxide deposit,Koillismaa complex 138
PGE reefs of the Penikat intrusion 138
Marginal series Cu-Ni-PGE andreef-type mineralization of theKoillismaa complex 139
Diverse Cu-Ni-PGE mineralizationsin the Portimo complex 140
PGE geochemistry 145
Summary and discussion 146
Central Lapland greenstone belt 154
Introduction 157
Main geologic units of northern Finland 157
Central Lapland greenstone belt 159
General features 159
Lithostratigraphy 159
Salla Group 161
Geochemistry and Nd isotopes 164
Geochronology 164
Onkamo Group 165
Geochemistry and Nd isotopes 7
Geochronology 7
Sodankylä Group 169
Geochemistry and geochronology. 170
Savukoski Group 171
Geochemistry 171
Geochronology 172
Kittilä Group 173
Stable isotopes 173
Field characteristics and geochemistryof mafi c metavolcanic rocks 174
Geochronology of mafi c rocks 175
Nuttio serpentinites and relateddikes 176
Felsic rocks 177
Lainio and Kumpu Groups 179
Metasediments 179
Metavolcanic rocks 180
Isotope studies of conglomerateclasts and detrital minerals 181
Mafi c plutonism 182
~2440 Ma intrusions in Lapland 182
Akanvaara intrusion 182
Koitelainen intrusion 184
Parental magma 185
Isotope geology 186
~2220 Ma differentiated sills 186
~2050 Ma intrusions 187
Keivitsa intrusion 187
Lapland granulite belt 189
Metamorphic conditions 190
Radiogenic isotopes 190
Summary and discussion 191
Mantle plume(s) and cracking ofthe craton 191
Cratonic sedimentation andvolcanism 192
Primitive volcanism anddeepening basins 192
Breakup of a supercontinent? 193
Ocean fl oor volcanism 194
Acid magmatism related to obduction? 196
Foreland basin 196
Terrestrial sedimentation andvolcanism 196
Correlation with Svecofenniansedimentation and volcanism 197
Relationship to the exhumation ofgranulites 197
Conclusions 198
Paleoproterozoic mafi c dikesin NE Finland 210
Introduction 213
Geological background 216
Mafi c dike swarms 218
~2.45 Ga dike swarms 219
Boninite–norite dikes 7
Gabbronorite dikes 7
Low-Ti tholeiitic dikes 7
Fe-tholeiitic dikes 7
Orthopyroxene-plagioclase-phyricdikes 7
Geochemical and isotopic characteristics 222
~2.32 Ga dike swarm andintrusions 226
~2.2 Ga layered sills and dikes 227
~2.1 Ga dike swarms 230
~1.98 Ga dike swarm 238
Tectonic signifi cance of the dikeswarms 241
Paleoproterozoic rifting events in the Archean Kuhmo block 241
Uplifted Archean high-gradeterranes 243
Ophiolites 252
Introduction 255
Signifi cance of ancient ophiolites 256
Age constrains for Finnish ophiolites 258
The Jormua ophiolite 259
The crustal unit 261
Petrology of the basalts 261
Gabbros and plagiogranites 266
The mantle section 267
Serpentinites 268
Clinopyroxenitic and hornblenditicmantle dikes of the westernblock 269
Outokumpu-type ultramafi c massifs 270
Ultramafi c rocks 272
Basaltic rocks 273
Cu-Co-Zn-Ni±Au sulfi de deposits 276
The Nuttio serpentinite belt 277
Comparative geochemistry of theFinnish ophiolites 279
Metaperidotites 279
Lavas and dikes 281
Environments of ophiolite formation 283
Concluding remarks 288
Karelian supracrustal rocks 294
Introduction 297
Geological setting and basin classification 297
Regional distribution of the supracrustalbelts 297
Metamorphism 300
Tectonic features 302
Basin classifi cation 302
Sumi tectofacies 305
Supracrustal rocks 305
2440 Ma layered intrusions 307
Sub-Sariola unconformity 307
Sariola tectofacies 310
North Karelia 310
Glaciogenic rocks of the UrkkavaaraFormation 310
Eastern part of the Kainuu belt 312
Glaciogenic rocks of the HonkajärviGroup 312
Kurkikylä Group 312
Western part of the Kainuu belt 314
Puolankajärvi Formation 8
Saari–Kiekki belt 314
Sariola cover of the layered intrusionswithin the basement complexes 315
Kuusamo belt 315
Peräpohja belt 315
Other Sariola occurrences 316
Sub-Kainuu unconformity 316
Kainuu tectofacies 318
Kainuu belt 318
Korvuanjoki Group in Kainuu 8
Middle and Upper part of theCentral Puolanka Group 8
North Karelia 320
Kuusamo and Kuusijärvi 321
Peräpohja 321
Other occurrences 321
Sub-Jatuli unconformity 322
Jatuli tectofacies 325
Koli and Kiihtelysvaara areas inNorth Karelia 325
East Puolanka Group and correspondinggroups in Kainuu 326
Kuusamo 326
Peräpohja 328
Other occurrences 328
Sub-Lower Kaleva unconformity 328
Lower Kaleva tectofacies 329
Kainuu belt 329
Höytiäinen basin, North Karelia 330
Kuopio area 330
Salahmi belt 332
Kiiminki belt 332
Peräpohja 333
Sub-Upper Kaleva unconformity 333
Upper Kaleva tectofacies 334
Upper Kaleva in Kainuu 334
Upper Kaleva within the Outokumpunappe complex and theKuopio–Pielavesi area 334
Problematic younger Karelian formations 335
Vihajärvi Group and Haapalanmäkiand Jokijyrkkä conglomerates 335
Pyssykulju Formation 336
Northern margin of the Peräpohjabelt 338
Himmerkinlahti Member and Kol -miloukkonen Formation in Posio 338
Karelian metadiabases 339
Previously proposed basin models 339
Continental and pericontinentalKarelia (sensu stricto) basins 339
Kaleva basins 340
Paleogeographic reconstructions 340
Continental–marginal Kareliansequences 341
Kaleva sequences 341
Synopsis 341
Karelia (sensu stricto) basin development 341
Lower Kaleva development 346
Upper Kaleva development 346
Closing comments 346
Svecofennian supracrustal rocks 358
Introduction 361
Geologic setting 361
General aspects 361
Proterozoic cover deposits of theArchean craton 364
Division of the Svecofenniandomain 365
U-Pb zircon ages and Nd isotopes 366
Geochemical and tectonomagmaticcharacterization of the volcanic rocks 369
Savo belt 370
General 370
Pielavesi–Pyhäsalmi region 371
Rautalampi region 373
Volcanic rocks of the Virtasalmiregion 373
Pohjanmaa belt 376
General 376
Evijärvi field 377
Ylivieska fi eld 377
Tampere and Pirkanmaa belts 380
General 380
Central Tampere belt 380
Western and eastern Tampere belt 384
Pirkanmaa belt 386
Supracrustal belts within the CentralFinland granitoid complex 389
Häme belt and Saimaa area 390
General 390
Volcanic rocks of the Häme belt 390
Volcanic rocks of the Saimaa area 392
Sedimentary rocks of the Saimaaarea 393
Uusimaa belt 395
General aspects 395
Kemiö–Järvenpää fi eld 395
Nauvo–Korppoo fi eld 400
Pellinki fi eld 400
Sedimentary carbonates of theUusimaa belt 403
Discussion 403
Correlation of the Pohjanmaa beltto northern Sweden 403
Correlation of the Uusimaa beltto the Bergslagen fi eld 405
Correlation of the Häme andUusimaa belts 406
Tiirismaa-type quartz arenites 407
Angular unconformities? 408
Summary 408
Svecofennian mafi c–ultramafi cintrusions 422
Introduction 425
Classification of the intrusions 425
Intrusions close to the craton margin(Group Ia) 427
Laukunkangas 429
Kotalahti 430
Lapinlahti gabbro–anorthosite 431
Intrusions of the Tampere and Pirkanmaabelts (Group Ib) 432
Ultramafi c intrusions of the VammalaNi province 434
Porrasniemi layered gabbro 437
Kaipola layered intrusion 438
Synvolcanic intrusions of the Arc complexof southern Finland (Group II) 441
Forssa gabbro 441
Hyvinkää layered intrusion 441
Ti-Fe-P gabbros of the Central Finlandgranitoid complex (Group III) 443
Kauhajärvi gabbro province 443
Kauhajärvi gabbro 444
Perämaa gabbro 445
Koivusaarenneva layeredintrusion 445
Chemical and isotope compositionof the mafi c–ultramafi c intrusions 447
Economic aspects and petrogenesis of theores 450
Concluding remarks 452
Proterozoic orogenic granitoid rocks 458
Classifi cation of plutonic rocks 461
Preorogenic rocks 464
Preorogenic rocks of centralFinland (1.93–1.91 Ga) 464
Preorogenic rocks of northernFinland (1.95–1.91 Ga) 464
Synorogenic rocks 465
Synkinematic rocks of southern and central Finland (1.89–1.87 Ga) 466
Postkinematic rocks of centralFinland (1.88–1.86 Ga) 467
Synorogenic rocks of northernFinland (1.89–1.86 Ga) 470
Lateorogenic granites 471
Lateorogenic granites of southernFinland (1.84–1.81 Ga) 471
Lateorogenic granites of northernFinland (1.84–1.80 Ga) 473
Postorogenic rocks 474
Postorogenic rocks of southernFinland (1.81–1.77 Ga) 474
Postorogenic granites of northernFinland (1.80–1.77 Ga) 477
Geochemical comparison and petrogeneticimplications 477
Preorogenic rocks 477
Synorogenic rocks 483
Synkinematic rocks of southernand central Finland 483
Postkinematic rocks of centralFinland 483
Synorogenic rocks of northernFinland 484
Lateorogenic granites 484
Postorogenic rocks 485
Discussion 486
Summary 489
Paleoproterozoic tectonic evolution 496
Introduction 499
Geologic outline 504
Pre-1.92 Ga crustal components andcrustal-scale boundaries 508
Lapland–Kola area 509
Karelian craton 511
Norrbotten Archean nucleus andattached island arcs 512
Keitele microcontinent andattached island arc 513
Bothnia microcontinent andattached island arc 513
Bergslagen microcontinent andTavastia island arc 514
Terminology related to the Paleoproterozoictectonic evolution 514
Tectonic model 515
Breakup of the Archean craton (orcratons) at 2.06 Ga 515
Lapland–Kola orogen 516
Lapland–Savo orogen 519
Subduction reversal and switchover:prelude to the Fennianorogeny at 1.90 Ga 520
Fennian orogeny: a north–southaccretion stage at 1.89–1.87 Ga 522
Attempted orogenic collapseand related magmatism at1.89–1.87 Ga 523
The end of the Fennian orogeny at1.87–1.85 Ga: orogenic collapse 524
Svecobaltic orogeny: Andean-typeactive margin and continent–continentcollision at 1.84–1.80 Ga 526
The Nordic orogeny: continent–continent collision at 1.82–1.79Ga 528
End of the Nordic orogeny andorogenic collapse at 1.79–1.77 Ga 529
Gothian evolution at 1.73–1.55 Ga 530
Discussion 531
Comparison with modern analogues 531
Comparison with earlier studiesand models 532
Concluding remarks 535
Rapakivi granites 548
Introduction 551
What is rapakivi granite? 551
Distribution, mode of occurrence,and age 552
Lithologic association 554
Felsic plutonic rocks 555
Mafi c plutonic rocks 560
Intermediate plutonic rocks 561
Dikes and volcanic rocks 561
Chemical composition 564
Origin of the rapakivi texture 565
Origin of the rapakivi magma 567
Tectonic scenarios 571
Future challenges 572
Sedimentary rocks, diabases, andlate cratonic evolution 578
Introduction 581
Mesoproterozoic sedimentarysequences 582
Regional setting 582
The Satakunta Formation and itssubmarine extensions 584
The Muhos Formation and itssubmarine extensions 588
Minor occurrences 589
Mesoproterozoic igneous rocks 589
Introduction 589
The ~1265 Ma magmatism 589
Regional setting 589
Petrography and geochemistry 590
Source characteristics and magmaticevolution 591
The 1100–1000 Ma magmatism 592
Geochemistry and source characteristics 11
Neoproterozoic and early Paleozoicsedimentary sequences 594
Regional setting 594
The Hailuoto Formation and itssubmarine extensions 595
The Lauhanvuori Formation 595
The bottom of the Bothnian andÅland seas 596
The Dividal Group of northwesternLapland 597
Minor occurrences 598
Allochthonous rocks of the FinnishCaledonides 599
Introduction and regional setting 599
The Lower Allochthon (JertaNappe) 600
The Middle Allochthon (Nalganasand Nabar Nappes) 600
The Upper Allochthon (VaddasNappe) 600
Paleosols and Cenozoic sedimentaryremnants 601
Tectonic evolution from the Mesoproterozoicto the Cenozoic 602
Introduction 602
The intracratonic rift basin stage(~1600–1300 Ma) 603
Crustal extension episodes and theSveconorwegian orogeny (~1300–900 Ma) 604
The Neoproterozoic exhumationstage (~900–600 Ma) 604
The stage of platform sedimentation(~600–420 Ma) 606
The Caledonian foreland stage(~420–350 Ma) and the fi nalexhumation of the shield 608
Concluding remarks 608
Kimberlites, carbonatites, and alkalinerocks 620
Introduction 623
Description of alkaline rock complexesof Finland 623
The Archean Siilinjärvi carbonatite 623
Proterozoic Kortejärvi and Laivajokiintrusions 626
Proterozoic lamprophyre dikes 630
Proterozoic Halpanen carbonatite 632
Proterozoic Group II kimberlites –olivine lamproites (K2L) 632
Neoproterozoic Group I kimberlites 634
Devonian Sokli carbonatitecomplex 636
Devonian Sokli ultramafi clamprophyre dikes 642
Devonian Iivaara alkaline complex 643
Geochemistry of kimberlites, carbonatites,and alkaline rocks 644
Isotope composition of kimberlites,carbonatites, and alkaline rocks 648
The kimberlite mantle sample 651
Mantle xenoliths 651
Mantle xenocrysts 653
Diamonds 654
Drift history of the shield 660
Introduction 663
Remanent magnetization in the FennoscandianShield 663
Fennoscandian drift history in the Precambrian 665
Neoarchean 666
Continental rifting at 2.4 Ga 667
Jatulian rifting and magmatismat 2.2–2.0 Ga 668
Onset of the Svecofennian orogenyat 2.0–1.9 Ga 668
Svecofennian orogeny at1.9–1.8 Ga 669
Subjotnian magmatic interval at1.65–1.5 Ga 670
Postjotnian time at ~1.26 Ga 670
Dike magmatism at 1.1–1.0 Ga 670
Position of the Fennoscandian Shieldin the continental assemblies of thePrecambrian 671
Early Paleoproterozoic 671
Middle Paleoproterozoic 673
Late Paleoproterozoic 674
Middle Mesoproterozoic 675
Late Mesoproterozoic 675
Conclusions 676
Paleoproterozoic carbon isotopeexcursion 684
Introduction 687
Early records 687
Fennoscandian d13C data 688
Global d13C data 690
Discussion 691
Conclusions 693
History of Finnish bedrock research 696
Introduction 699
Finnish geology in the 19th century 699
Research organizations 701
From the Geological Commissionto the Geological Survey 701
Universities 702
Mining enterprises 704
Other research organizations 705
Main fields of research 706
Petrology and physical geology 706
Geochemistry and isotope geology 710
Mineralogy 711
Economic geology 713
Synopsis 714
Contributors 718
Index of persons and institutions 722
Locality index 724
Subject index 730

Produkt-Details

• Erscheint lt. Verlag: 1.11.2006
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Geologie
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Mineralogie / Paläontologie
• Themenwelt: Technik
• ISBN-10: 0-08-045759-2 / 0080457592
• ISBN-13: 978-0-08-045759-8 / 9780080457598