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Table of Contents - Special Paper 344

Eocene and Oligocene Paleosols of Central Oregon


Abstract 1
Introduction 2
Geological setting
  Clarno area 2
  Painted Hills area 3
  Biostratigraphy 3
  Geochronology 6
Features of the paleosols
  Traces of land life 7
  Soil horizons 15
  Soil structure 19
  Conclusions 22
Burial alteration of the paleosols
  Loss of organic matter 23
  Burial gleization 23
  Burial reddening 23
  Calcite cementation 24
  Silicification 24
  Zeolitization 24
  Celadonitization 26
  Illitization 27
  Feldspathization 28
  Compaction 28
  Thermal maturation of organic matter 28
  Recrystallization 28
  Conclusions 29
Description and classification of the paleosols 29
  Pswa pedotype (Lithic Hapludalf) 33
  Scat pedotype (Haplumbrept) 36
  Cmuk pedotype (Hemist) 40
  Pasct pedotype (Sombrihumult) 42
  Patat pedotype (Psammentic Eutrochrept) 45
  Sayayk pedotype (Tropofluvent) 49
  Luquem pedotype (Typic Udivitrand) 52
  Lakayx pedotype (Hapludult) 53
  Acas pedotype (Plinthic Haplohumult) 57
  Nukut pedotype (Lithic Kanhapludult) 59
  Apax pedotype (Andic Dystropept) 63
  Tiliwal pedotype (Plinthic Kandiudox) 67
  Sitaxs pedotype (Placaquand) 70
  Luca pedotype (Hapludalf) 74
  Micay pedotype (Aquandic Fluvaquent) 78
  Lakim pedotype (Aquandic Placaquept) 82
  Kskus pedotype (Fluvent) 85
  Tuksay pedotype (Plinthic Paleudult) 87
  Sak pedotype (Typic Paleudult) 90
  Ticam pedotype (Andic Eutrochrept) 94
  Wawcak pedotype (Entic Chromudert) 96
  Yanwa pedotype (Histic Humaquept) 100
  Skwiskwi pedotype (Eutric Fulvudand) 106
  Maqas pedotype (Vitric Haplustand) 111
  Xaxus pedotype (Aquic Ustivitrand) 116
  Yapas pedotype (Mollic Haplustand) 121
Reconstructed paleosols and their environments 122
  Middle Eocene (44 Ma) volcanic facies, Clarno Formation 126
  Middle Eocene (43 Ma) purple-red beds, Clarno Formation 129
  Middle Eocene (42 Ma) brick-red beds, Clarno Formation 130
  Late-middle Eocene (40 Ma) mammal quarry, Clarno Formation 131
  Middle-late Eocene (38 Ma) lower Big Basin Member, John Day Formation 132
  Early Oligocene (33 Ma) middle Big Basin Member, John Day Formation 133
  Mid-Oligocene (31 Ma) upper Big Basin Member, John Day Formation 135
  Late Oligocene (29 Ma) Turtle Cove Member, John Day Formation 136
  Eocene-Oligocene paleoenvironmental change 138
Acknowledgments 139
Appendices
1. Individual named paleosols 142
2. Textures of the paleosols 144
3. Mineral composition of the paleosols 151
4. Chemical composition of the paleosols 158
5. Trace element composition of the paleosols 162
6. Appendix 6. Molecular weathering ratios of the paleosols 166
7. Appendix 7. Checklist of middle Eocene fossils from the Clarno Nut Beds 171
8. Checklist of late middle Eocene fossils from the Clarno Mammal Quarry 175
9. Checklist of late Middle Eocene fossils from near Whitecap Knoll 176
10. Checklist of early Oligocene fossils from near Clarno 177
11. Checklist of early Oligocene fossils from Painted Hills 179
12. Appendix 12. Checklist of late Oligocene fossils from Carroll Rim 181
References Cited 182