The K/T Boundary of Gams (Eastern Alps, Austria) and
the Nature of Terminal Cretaceous Mass Extinction ............... 1
Preface ......................................................... 3
Introduction
by A.F. Grachev .............................................. 7
Chapter 1. A Review of the Geology of the Late Cretaceous-
Paleogene Basin of Gams (Eastern Alps, Austria)
by H.A. Kollmann .................................. 9
1.1. Introduction ............................................... 9
1.2. Outline of the Tectonic History ............................ 9
1.3. The Cretaceous-Paleogene Boundary in Alpine Deposits ...... 10
1.4. The Gosau Group of Gams ................................... 10
1.5. Termination of the Gosau Cycle ............................ 13
1.6. Locations of Sections Studied and Samples Preparation ..... 13
Chapter 2. Biostratigraphy
by O.A. Korchagin and H.A. Kollmann .............. 19
2.1. Introduction .............................................. 19
2.2. Foraminiferal Assemblages ................................. 19
2.3. Preservation of Foraminifera .............................. 21
2.4. Terminal Maastrichtian .................................... 21
2.5. Lower Paleogene ........................................... 22
2.6. Association of Planktonic Foraminifera .................... 23
Chapter 3. Geochemistry of Rocks in the Gams Stratigraphic
Sequence
by A.F. Grachev .................................. 39
3.1. Introduction .............................................. 39
3.2. Methods of Material Preparation and Studying .............. 39
3.3. Whole Rock Chemistry ...................................... 41
3.4. Trace and Rare Earth Elements ............................. 43
3.5. Isotopic Composition of Helium, Carbon, and Oxygen ........ 54
Chapter 4. Minerals of the Transitional Layer in
Gams Sections
by A.F. Grachev, S.E. Borisovsky, and
V.A. Tsel'movich ................................. 59
4.1. Introduction .............................................. 59
4.2. Sampling Procedure, Sample Preparation Techniques, and
Study Methods ............................................. 59
4.3. Mineral Paragenesis in the Gams Transitional Layer ........ 61
4.3.1. Native elements and metallic alloys ................ 61
4.3.2. Sulfides ........................................... 69
4.3.3. Oxides ............................................. 71
4.3.4. Carbonates ......................................... 81
4.3.5. Sulphates .......................................... 81
4.3.6. Phosphates ......................................... 81
4.3.7. Silicates .......................................... 82
4.3.8. Vertical mineralogical zonation as an indicator
of environments of the transitional layer
formation .......................................... 87
4.4. Conclusion ................................................ 88
Chapter 5. Magnetic Properties of Rocks of the Gams Section
by D.M. Pechersky, D.K. Nourgaliev, and
Z.V. Sharonova ................................... 89
5.1. Introduction .............................................. 89
5.2. Methods of Petromagnetic Studies .......................... 90
5.3. Results of Petromagnetic Studies of the Rocks From
Gams-1 Section ............................................ 95
5.3.1. Paramagnetic magnetization ........................ 111
5.3.2. Discussion of petromagnetic results ............... 111
5.4. Characterization of the Boundary Layer in the Gams
Sections ................................................. 113
5.5. Comparative Characterization of Sections Including
the K/T Boundary ......................................... 123
5.6. Conclusion ............................................... 133
Chapter 6. Cosmic Dust and Micrometeorites: Morphology and
Chemical Composition
by A.F. Grachev, O.A. Korchagin, and
V.A. Tsel'movich ................................ 135
6.1. Introduction ............................................. 135
6.2. Results of Investigations ................................ 136
6.3. Discussion ............................................... 143
6.4. Conclusion ............................................... 143
Chapter 7. Mantle Plumes and Their Influence on
the Lithosphere, Sea-level Fluctuations and
atmosphere
by A.F. Grachev ................................. 147
7.1. Introduction ............................................. 147
7.2. Mantle Plumes and Lithosphere ............................ 147
7.3. Underplating, Topography and Sea-Level Changes ........... 152
7.4. Mantle Plumes and Atmosphere ............................. 157
Chapter 8. Nature of the K/T Boundary and Mass Extinction
by A.F. Grachev ................................. 165
8.1. Introduction ............................................. 165
8.2. A Two-Stages Evolution of the Transitional Layer ......... 166
8.3. Mantle Plumes and Mass Extinctions ....................... 167
8.3.1. Arsenic at the Cretaceous-Paleogene boundary ...... 169
8.3.2. Poisoning by toxic elements at the K/T
boundary: The killing mechanism sensu stricto ..... 170
Conclusion
by A.F. Grachev ............................................ 173
References .................................................... 175
Electronic Supplement ......................................... 188
Author Index .................................................. 189
Subject Index ................................................. 195
|
