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Table of Contents - Special Paper 313

Ordovician K-bentonites of Eastern North America

Abstract

Introduction and Purpose

Geologic Setting

Field Identification of K-bentonites

Previous Investigations

1920s and Early 1930s
Mid-1930s Through Late 1970s
1980s to Present Mineralogical and Chemical Characteristics

Clay Mineralogy

Age of Illitization
Layer Charge of I/S in K-bentonites
High Resolution Transmission Electron Microscopy
Petrography
Chemistry
Chemical Fingerprinting Biostratigraphic Framework

K-bentonite Distribution in Eastern North America

Upper Mississippi Valley
Eastern Missouri
Illinois Basin
Central and Northern Kentucky and Southern Ohio
Central Tennessee
Southernmost Appalachians
Southwestern Virginia and Eastern Tennessee
Western Outcrop Belt
Central Outcrop Belt
Eastern Outcrop Belt Northern Virginia and Eastern West Virginia
Central Pennsylvania
New York
Southern Ontario
Michigan Basin
St. Lawrence Lowlands and Quebec
Western Newfoundland
Eastern Oklahoma–Arkoma Basin
Western Iowa, Eastern Kansas, and Nebraska
Texas Regional Correlation of K-bentonites

Ibexian Series
Whiterockian Series
Mohawkian Series
Deicke K-bentonite Bed
Millbrig K-bentonite Bed
Other Widespread Mohawkian K-bentonite Beds Cincinnatian Series Regional Cross Sections

Eastern Missouri–Southeastern Minnesota Cross Section
Eastern Missouri–Southern Ontario Cross Section
Eastern Missouri–Eastern Ohio Cross Section
Eastern Missouri–Western Virginia Cross Section
Southern Ohio–Western Virginia Cross Section
Northeastern Kentucky–Northeastern Alabama Cross Section Tectonic Setting and Origin of K-bentonites

Composition of Parental Magmas
Tectonic Setting Event Stratigraphic Implications

Summary and Conclusions

Acknowledgments

Appendix 1. Locality Register

References Cited