JOHN DAY FOSSIL BEDS Geology and Paleoenvironments of the Clarno Unit John Day Fossil Beds National Monument, Oregon

COVER

ABSTRACT

ACKNOWLEDGEMENTS

CHAPTER I: INTRODUCTION AND REGIONAL GEOLOGY

INTRODUCTION

PREVIOUS WORK AND REGIONAL GEOLOGY
   Basement rocks
   Clarno Formation
   John Day Formation

CHAPTER II: GEOLOGIC FRAMEWORK

INTRODUCTION
   Stratigraphic nomenclature
   Radiometric age determinations

CLARNO FORMATION LITHOSTRATIGRAPHIC UNITS
   Lower Clarno Formation units
   Main section

JOHN DAY FORMATION LITHOSTRATIGRAPHIC UNITS
   Lower Big Basin Member
   Middle and upper Big Basin Member
   Turtle Cove Member

GEOCHEMISTRY OF LAVA FLOW AND TUFF UNITS
   Basaltic lava flows
   Geochemistry of andesitic units
   Geochemistry of tuffs

STRUCTURE OF CLARNO UNIT AREA
   Structural analysis of folded strata

SEDIMENTATION AND VOLCANISM
   Clarno Formation depositional setting
   John Day Formation depositional setting

LATE EOCENE PALEOCLIMATE AND TECTONICS
   Step-wise change in paleosol weathering trends

CHAPTER III: PALEOSOLS AND PALEOENVIRONMENTS

INTRODUCTION

FEATURES OF THE PALEOSOLS
   Traces of land life
   Soil horizons
   Soil structure

BURIAL ALTERATION OF PALEOSOLS

DESCRIPTION AND INTERPRETATION OF PEDOTYPES
   Acas paleosols
   Cmuk paleosols
   Lakayx paleosols
   Lakim paleosols
   Luca paleosols
   Luquem paleosols
   Micay paleosols
   Pasct paleosols
   Patat paleosols
   Pswa paleosols
   Sayayk paleosols
   Scat paleosols
   Sitaxs paleosols

CHAPTER IV: PALEOENVIRONMENTAL SUMMARY

Deposition of Clarno volcaniclastic deposits
Deposition of "Red Hill" claystones
Deposition of "Mammal Quarry" siltstones
Summary

REFERENCES

APPENDICES

GLOSSARY