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Table of Contents - Special Paper 249:

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The Cretaceous/Tertiary Boundary Interval, Raton Basin, Colorado and New Mexico, and its Content of Shock-Metamorphosed Minerals; Evidence Relevent to the K/T Boundary Impact-Extinction Theory


Acknowledgments

Abstract

Introduction

Purpose of the study

K/T boundary interval rocks in the Raton Basin

Rocks directly underlying the K/T boundary claystone

K/T boundary claystone bed

Microstratigraphic relationships
Contact relationships
Chemical composition of the K/T boundary claystone
Authigenic spherules
Origin of spherules
Origin of the K/T boundary claystone

K/T boundary impact layer

Chemical composition of the K/T boundary impact layer
Origin of iridium anomaly
Origin of the K/T boundary impact layer

Rocks directly overlying the K/T boundary impact layer

Clastic mineral grains of the K/T boundary impact layer

Shock-metamorphosed minerals

Shock-metamorphosed features in K/T boundary clastic minerals

Shock lamellae
Indices of refraction of shocked quartz
Mosaicism
Thetomorphic glass
Stishovite

Origin of shock-metamorphic features in K/T boundary minerals

Information gained from study of K/T boundary rocks
Information gained from study of pyroclastic rocks

Amount of shock-metamorphosed minerals in the K/T boundary impact layer

Shape of shock-metamorphosed mineral grains

Size of shock-metamorphosed mineral grains

Location of the K/T boundary impact

K/T boundary impact crater size

K-Ar age of the K/T boundary

Conclusions

References cited