Archean Evolution of the Pilbara Craton and Fortescue Basin

Description

One of today’s major geoscientific controversies centres on the origin of the Archean granite‒greenstone terranes. Is the geology of these scattered remnants of our planet’s early crust consistent with the theory that modern-style plate-tectonic processes operated from the early Archean, or does it indicate that tectonic and magmatic processes were different in the Archean? Earth has clearly evolved since its initial formation, so at what stage did its processes of crustal growth first resemble those of today? The logical place to seek answers to these intriguing and important questions is within the best-preserved early Archean crust. The Pilbara region of northwest Australia is internationally famous for its abundant and exceptionally well-preserved fossil evidence of early life. However, until recently the area has received much less recognition for the key evidence it provides on early Archean crustal evolution. This book presents and interprets this evidence through a new stage-by-stage account of the development of the Pilbara’s geological record between 3.53 and 2.63 Ga. The Archean Pilbara crust represents one fragment of Earth’s oldest known supercontinent Vaalbara, which also included the Kaapvaal Craton of southern Africa. Recognition of Vaalbara expands the background database for both these areas, allowing us to more fully understand each of them.  Preface Acknowledgements About This Book Contents About the Author List of Figures List of Tables Chapter 1: Outline of the Pilbara Craton 1.1 Introduction 1.1.1 Investigations of the Pilbara Craton 1.2 Stratigraphy of the Northern Pilbara Craton 1.3 Tectonic Units 1.3.1 Terminology 1.3.2 Summary of Tectonic Units 1.4 Fragment of an Archean Continent 1.5 Vaalbara Continent? 1.6 Concept of an `Ancient Nucleus´ 1.7 Concealed Pilbara Craton References Chapter 2: Eoarchean and Early Paleoarchean Crust of the Pilbara Craton 2.1 Introduction 2.2 Eoarchean to Early Paleoarchean Crust (3800-3530 Ma) 2.2.1 U-Pb Zircon Geochronology 2.2.1.1 Pre-3530 Ma Xenocrystic Zircons in Felsic Igneous Rocks 2.2.1.2 Evidence from 207Pb/206Pb Ages of Detrital Zircons 2.2.1.2.1 Specific Evidence on Provenance 2.2.1.2.2 General Evidence on Provenance 2.2.1.2.3 Statistical Analysis of Data 2.2.2 Sm-Nd Isotope Data 2.2.2.1 Depleted or Chondritic Paleoarchean Mantle? 2.2.2.2 Sm-Nd Isotope Data from the East Pilbara 2.2.2.3 Model Ages 2.2.2.4 Epsilon Nd Values 2.2.3 Lu-Hf Isotopes in Zircon 2.2.3.1 Previous Investigations 2.2.3.2 Current Zircon Lu-Hf Data 2.2.3.3 Lu-Hf Analysis of Detrital Zircons 2.2.3.4 Lu-Hf Analysis of Cognate and Inherited Zircons 2.3 Conclusions References Chapter 3: Warrawoona Large Igneous Province, 3530-3427 Ma 3.1 Introduction 3.1.1 Preservation of the Warrawoona Group 3.2 Stratigraphy 3.2.1 Coonterunah Subgroup 3.2.1.1 Table Top Formation 3.2.1.2 Coucal Formation 3.2.1.3 Double Bar Formation 3.2.2 Talga Talga Subgroup 3.2.2.1 North Star Basalt 3.2.2.2 Dresser Formation 3.2.2.3 McPhee Formation 3.2.3 Coongan Subgroup 3.2.3.1 Mount Ada Basalt 3.2.3.1.1 Earth´s Oldest Asteroid Impact Spherules 3.2.3.2 Duffer Formation 3.2.3.2.1 Marble Bar Chert Member 3.2.4 Salgash Subgroup 3.2.4.1 Apex Basalt 3.2.4.2 Panorama Formation 3.3 Origin of the Warrawoona Group 3.4 Evolution of the Warrawoona Group 3.5 Large Igneous Province 3.6 Granitic Supersuites of the Warrawoona LIP 3.6.1 Mulgundoona Supersuite (3530-3490 Ma) 3.6.2 Callina Supersuite (3484-3462 Ma) 3.6.3 Tambina Supersuite (3451-3416 Ma) 3.6.4 Emu Pool Supersuite (3324-3290 Ma) 3.6.5 Cleland Supersuite (3270-3223 Ma) 3.7 Tectonic Setting of the Warrawoona LIP 3.7.1 Plate Tectonic Models 3.7.2 Oceanic Plateau? References Chapter 4: Strelley Pool Formation: Continental Sedimentation Between Paleoarchean LIPs 4.1 Introduction 4.2 Stratigraphy 4.2.1 Stratigraphic Rank: Formation or Group? 4.2.2 Relations to the Panorama Formation 4.2.3 Unconformities 4.3 Geochronology 4.4 World´s Oldest Paleosols 4.5 Suggestion of Hydrothermal Deposition 4.6 Correlation with the Buck Reef Chert 4.7 Fossil Record 4.7.1 Stromatolites 4.7.1.1 Stromatolite Morphology 4.7.2 Microfossils 4.7.3 Microbial Mats 4.8 Significance to Crustal Evolution 4.9 Conclusions References Chapter 5: Kelly Large Igneous Province, 3350-3315 Ma 5.1 Introduction 5.1.1 Tectonic Setting 5.1.2 Kelly Large Igneous Province 5.2 Stratigraphy 5.2.1 Euro Basalt 5.2.2 Wyman Formation 5.2.3 Charteris Basalt 5.2.4 Unconformities within the Kelly Group 5.3 Komatiite and Komatiitic Basalt in the Kelly Group 5.4 Tholeiitic Basalt in the Kelly Group 5.5 Sm-Nd Isotope Data 5.6 Relevance to Continental Deposition of the Warrawoona Group 5.7 Granitic Rocks of the Kelly LIP 5.7.1 Emu Pool Supersuite (3324-3290 Ma) 5.7.1.1 Geochemistry 5.8 Emu Pool Event (3325-3290 Ma) References Chapter 6: Paleoarchean Continental Breakup of the Pilbara Craton 6.1 Introduction 6.2 East Pilbara Terrane Rifting Event 6.3 Stratigraphy 6.3.1 Sulphur Springs Group 6.3.1.1 Leilira Formation 6.3.1.2 Kunagunarrina Formation 6.3.1.3 Kangaroo Caves Formation 6.3.1.4 Analogies with the Fig Tree Group, Kaapvaal Craton 6.3.2 Roebourne Group 6.3.2.1 Ruth Well Formation 6.3.2.2 Weerianna Basalt 6.3.3 Cleland Supersuite 6.4 Continental Breakup 6.4.1 Evidence 6.4.1.1 Recognition of the Regal Basin 6.4.1.2 Passive Margin Successions 6.4.1.3 Evidence from Major Faults 6.4.1.3.1 Tabba Tabba Shear Zone 6.4.1.3.2 Sholl Shear Zone 6.4.1.4 Mesoarchean Differences between Northwest and East Pilbara 6.4.2 Other Fragments of the Paleoarchean Plateau References Chapter 7: Mesoarchean Rift and Marginal Basins of the Pilbara Craton 7.1 Introduction 7.2 Basaltic Rift Basins 7.2.1 Regal Basin 7.2.1.1 Regal Formation 7.2.1.2 Regal Thrust 7.3 Early Mesoarchean Passive Margins 7.3.1 Soanesville Basin 7.3.1.1 Cardinal Formation 7.3.1.1.1 Pincunah Banded-Iron Member 7.3.1.2 Corboy Formation 7.3.1.3 Paddy Market Formation 7.3.1.4 Honeyeater Basalt 7.3.1.5 Pyramid Hill Formation 7.3.1.6 Hong Kong Chert 7.3.1.7 Empress Formation 7.3.1.8 Tectonic Setting 7.3.1.9 Geochemistry 7.3.1.10 Geochronology 7.3.2 Nickol River Basin 7.3.2.1 Nickol River Formation 7.3.2.2 Tectonic Setting 7.3.2.3 Geochronology 7.3.3 Early Mosquito Creek Basin 7.3.3.1 Coondamar Formation 7.3.3.2 Budjan Creek Formation 7.3.3.2.1 Tectonic Setting 7.3.3.2.2 Geochronology 7.3.3.3 Tectonic Setting 7.3.3.4 Kurrana Shear Zone References Chapter 8: Mesoarchean Subduction in the Pilbara Craton 8.1 Introduction 8.2 Sholl Terrane 8.2.1 Whundo Group 8.2.1.1 Nallana Formation 8.2.1.2 Tozer Formation 8.2.1.3 Bradley Basalt 8.2.1.4 Woodbrook Formation 8.2.1.5 Geochemistry 8.2.1.6 Sm-Nd Isotope Data 8.2.1.7 Geochronology 8.2.2 Railway Supersuite 8.2.2.1 Pinnacle Hill Gneiss 8.2.2.2 Bullock Hide Intrusion 8.2.2.3 Twin Table Monzogranite 8.2.2.4 Geochemistry 8.2.2.5 Sm-Nd Isotope Data 8.2.2.6 Geochronology 8.3 Ophiolite (3220-3165 Ma Regal Formation) 8.4 Prinsep Orogeny and Elizabeth Hill Supersuite 8.4.1 Elizabeth Hill Supersuite 8.5 Magmatic Arcs of the De Grey Superbasin 8.5.1 Orpheus Supersuite 8.5.1.1 Andover Intrusion 8.5.1.2 Black Hill Well Monzogranite 8.5.1.3 Mount Gregory Monzodiorite 8.5.1.4 Forestier Bay Granodiorite 8.5.1.5 South Whundo Monzogranite 8.5.1.6 Geochemistry 8.5.1.7 Sm-Nd Isotope Data 8.5.1.8 Geochronology 8.5.2 Maitland River Supersuite 8.5.2.1 Granodiorite and Tonalite Intrusions 8.5.2.2 Monzogranite Intrusions 8.5.2.3 Geochemistry 8.5.2.4 Sm-Nd Isotope Data 8.5.2.5 Geochronology 8.5.3 Sisters Supersuite 8.5.3.1 Indee Suite 8.5.3.1.1 Geochemistry 8.5.3.1.2 Sm-Nd Isotope Data 8.5.3.2 Portree Suite 8.5.3.3 Langenbeck Suite 8.5.3.3.1 Sherlock Intrusion 8.5.3.3.2 Opaline Well Intrusion 8.5.3.3.3 Millindinna Intrusion 8.5.3.4 Radley Suite 8.5.3.4.1 Munni Munni Intrusion 8.5.3.4.2 Radio Hill Intrusion 8.5.3.4.3 Geochemistry 8.5.3.4.4 Geochronology References Chapter 9: Mesoarchean Basin Evolution Inland of Magmatic Arcs 9.1 Introduction 9.2 De Grey Supergroup 9.2.1 Gorge Creek Group 9.2.1.1 Farrel Quartzite 9.2.1.1.1 Depositional Environment 9.2.1.2 Cleaverville Formation 9.2.1.2.1 Depositional Environment 9.2.1.3 Cundaline Formation 9.2.2 Regional Stratigraphic Continuity 9.2.2.1 Stratigraphic Continuity Between Greenstone Belts 9.2.3 Conclusions regarding the Gorge Creek Basin 9.2.4 Geochronology 9.2.4.1 Geochronology at Nunyerry Gap 9.2.4.2 Geochronology at Shay Gap 9.2.5 Coonieena Basalt 9.2.6 Croydon Group 9.2.6.1 Cattle Well Formation 9.2.6.2 Lalla Rookh Sandstone 9.2.6.3 Constantine Sandstone 9.2.6.4 Mallina Formation 9.2.7 Whim Creek Group 9.2.7.1 Warambie Basalt 9.2.7.2 Red Hill Volcanics 9.2.7.3 Geochronology 9.2.8 Bookingarra Group 9.2.8.1 Cistern Formation 9.2.8.2 Rushall Slate 9.2.8.3 Louden Volcanics 9.2.8.4 Mount Negri Volcanics 9.2.8.5 Kialrah Rhyolite 9.2.8.6 Geochronology 9.3 Tectonic Evolution of the De Grey Superbasin References Chapter 10: Orogenies, Cratonization, and Post-Orogenic Granites 10.1 Introduction 10.1.1 North Pilbara Orogeny 10.1.1.1 Lalla Rookh-Western Shaw Structural Corridor 10.1.1.2 Tabba Tabba Shear Zone 10.1.1.3 Sholl Shear Zone 10.1.1.4 Loudens Fault 10.1.2 Mosquito Creek Orogeny 10.1.2.1 Kurrana Shear Zone 10.2 Cutinduna Supersuite 10.3 Split Rock Supersuite References Chapter 11: Mineralization in the Northern Pilbara 11.1 Paleoarchean Mineralization 11.1.1 Sediment-Hosted, Hydrothermal Massive Sulphates 11.1.2 Volcanogenic Massive Sulphides 11.1.3 Black Shale-Hosted Cu-Zn 11.1.4 Vein and Hydrothermal Base Metals 11.1.5 Copper and Molybdenum Mineralization 11.1.6 Precious Metals 11.1.6.1 Gold Mineralization during Doming 11.2 Mineralization during the EPTRE 11.2.1 Sulphur Springs Group 11.2.1.1 Hydrothermal Barite Mineralization 11.2.2 Roebourne Group 11.2.2.1 Komatiite-Hosted Ni-Cu 11.2.3 VMS Cu-Zn Mineralization, Tabba Tabba Shear Zone 11.2.4 Soanesville Group 11.2.4.1 Iron Ore: Supergene Enrichment of Banded Iron Formation 11.2.4.2 Ni-Cu and PGE Mineralization 11.2.4.3 Gold Potential of the Nickol River Formation 11.3 Mesoarchean Mineralization 11.3.1 Mineralization during Closure of the Regal Basin 11.3.1.1 Karratha Event Mineralization 11.3.1.2 Sholl Terrane VMS 11.3.1.3 Gold Mineralization 11.3.2 Gold and Copper North of the Sholl Shear Zone 11.3.3 Mineralization in the De Grey Superbasin 11.3.3.1 Iron Ore in the Gorge Creek Basin 11.3.3.2 Mallina Basin Mineralization 11.3.3.2.1 Sanukitoid-Related Gold and PGE Mineralization 11.3.3.2.2 Orogenic Lode Au and Au-Sb Deposits 11.3.3.2.3 VMS in the Whim Creek Greenstone Belt 11.3.3.2.4 V-Ti in the Sherlock Intrusion 11.3.3.2.5 Ni-Cu in the Sherlock Intrusion 11.3.3.2.6 Radley Suite Ni-Cu and PGE 11.3.3.2.7 Conglomerate-Hosted Gold Mineralization 11.3.4 Gold in the Mosquito Creek Basin 11.3.5 Post-Orogenic Mineralization (2895-2830 Ma) 11.3.5.1 Lithium-Bearing Pegmatites 11.3.5.2 Pegmatite of the 2851-2831 Ma Split Rock Supersuite 11.3.5.3 Gold Mineralization 11.4 Neoarchean Mineralization References Chapter 12: Fortescue Group: The Neoarchean Breakup of the Pilbara Craton 12.1 Introduction 12.1.1 Re-Definition of the Fortescue Group 12.2 Stratigraphy 12.2.1 Tectono-Stratigraphic Sequences 12.2.1.1 Sequence 1 12.2.1.1.1 Bellary Formation 12.2.1.1.2 Mount Roe Basalt 12.2.1.1.2.1 Geochronology 12.2.1.2 Sequence 2 12.2.1.2.1 Hardey Formation 12.2.1.2.1.1 Bamboo Creek Member 12.2.1.2.1.2 Koongaling Volcanic Member 12.2.1.2.1.3 Warri Warri and Tanguin Members 12.2.1.2.1.4 Lyre Creek Member 12.2.1.2.1.5 Coolajacka Member 12.2.1.2.1.6 Geochronology 12.2.1.3 Sequence 3 12.2.1.3.1 Kylena Formation 12.2.1.3.1.1 Mopoke Member 12.2.1.3.1.2 Cooya Pooya Dolerite 12.2.1.3.1.3 Kylena Formation in the Marble Bar Sub-Basin 12.2.1.3.1.4 Geochronology 12.2.1.4 Sequence 4 12.2.1.4.1 Tumbiana Formation 12.2.1.4.2 Maddina Formation 12.2.1.4.2.1 Kuruna Member 12.2.1.4.3 Pear Creek Formation 12.2.1.4.4 Geochronology 12.2.1.5 Sequence 5 12.2.1.5.1 Jeerinah Formation 12.2.1.5.1.1 Baramine Volcanic Member 12.2.1.5.1.2 Isabella Member 12.2.1.5.1.3 Woodiana Member 12.2.1.5.1.4 Warrie Member 12.2.1.5.1.5 Nallanaring Volcanic Member 12.2.1.5.1.6 Roy Hill Member 12.2.1.5.2 Geochronology References