Understanding Late Devonian and Permian-Triassic Biotic and Climatic Events (eBook)

Contents 5
Introduction 7
References 9
Toward understanding Late Devonian global events: few answers, many questions 11
Introduction 11
Magnitude and rank of biotic changes 14
Timing of the key boundaries 17
Marine vs. terrestrial events 18
High-resolution (bio)geochemical patterns 19
Low- vs. high-latitude domains 23
Tectonic and volcanic activity 25
Cyclostratigraphical perspective 28
Two eustatic dilemmas 28
Implications and conclusions 29
Acknowledgments 31
References 32
Modelling Late Devonian extinction hypotheses 43
Introduction: modelling Late Devonian climates and extinctions 43
Direct-effect global winter models 45
Direct-effect greenhouse models 47
Lag-time greenhouse-collapse models 49
Testing the models? 50
Discussion of recent research results 52
Conclusions 53
Acknowledgements 54
References 54
Sedimentary fill of the Late Devonian Flynn Creek crater: a hard target marine impact 57
Introduction 57
Description of crater fill 59
Stratigraphic relationships 62
Reconstruction of impact-related processes and depositional history 65
Comparison to other marine impacts 70
Time of impact 70
Conclusions 72
Acknowledgments 73
Locality information 73
References 74
Devonian stromatoporoid originations, extinctions, and paleobiogeography: how they relate to the Frasnian-Famennian extinction 77
Introduction 77
Originations and extinctions 78
Paleobiogeography and changing sea level 78
Givetian sea-level rise: the Taghanic Onlap 86
The Frasnian record 88
The Frasnian-Famennian extinction 92
The Famennian record 93
Unknowns 94
Conclusions 94
Acknowledgments 95
References 95
Using environmental niche modeling to study the Late Devonian biodiversity crisis 99
Introduction 99
Methods 101
Results and discussion 118
Conclusions 127
Acknowledgments 128
References 128
Subdivision of the terminal Frasnian linguiformis conodont Zone, revision of the correlative interval of Montagne Noire Zone 13, and discussion of stratigraphically significant associated trilobites 187
Introduction 187
The linguiformis Zone and its subdivision 188
Occurrences of Palmatolepis linguiformis 189
Revision of Zone 13 of the Montagne Noire zonation 195
Frasnian/Famennian boundary 196
Numerical patterns in conodont diversity and biofacies 197
Trilobites in the linguiformis Zone 198
Acknowledgments 200
References 200
Productivity and bottom water redox conditions at the Frasnian–Famennian boundary on both sides of the Eovariscan Belt: constraints from trace-element geochemistry 205
Introduction 205
Investigated sections 206
Methods 210
Results 211
Interpretation 217
Discussion 221
Conclusions 225
Acknowledgements 225
References 226
Evidence for Late Devonian (Kellwasser) anoxic events in the Great Basin, western United States 231
Introduction 231
Regional geology of the Great Basin 232
Analytical procedure and rationale 234
Great Basin sections 237
Discussion 257
Anoxia as an extinction mechanism 261
Acknowledgements 263
References 263
Late Permian double-phased mass extinction and volcanism: an oceanographic perspective 269
Introduction 269
Circulation in the Panthalassa superocean 274
End-Permian plankton collapse and setting of the Chert Gap 275
Late Permian climate 276
Volcanogenic breakdown of the thermohaline system 279
Stepwise volcanic modulation in different climatic belts 283
Consequences of subaerial versus seafloor volcanism 286
End-Guadalupian crisis and a potential volcanic cause 288
Discussion 289
Conclusions and implications 290
Acknowledgements 293
References 293
Fossil preservation during the aftermath of the end-Permian mass extinction: taphonomic processes and palaeoecological signals 305
Introduction: the potential Early Triassic preservation bias 305
Methods 307
Preservation of Early Triassic skeletonized invertebrate benthic marine fossils 308
Environmental and ecological effects upon Early Triassic early diagenetic processes 311
Testing the quality and utility of the Lower Triassic fossil record of skeletonized invertebrate benthic marine fossils 313
Conclusions 313
Acknowledgments 314
References 314
Environmental trends of Early Triassic biofabrics: implications for understanding the aftermath of the end-Permian mass extinction 319
Introduction 319
Geologic setting 320
Methods 320
Palaeoenvironmental analysis 321
Trace fossils and ichnofabric indices 326
Microbial structures 328
Discussion 330
Conclusion 335
Acknowledgments 336
References 336
Subject Index 339