Skip to Main Content
Book Chapter

Manson and company: impact structures in the United States

By
Christian Koeberl
Christian Koeberl
Institute of Geochemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
Search for other works by this author on:
Raymond R. Anderson
Raymond R. Anderson
Iowa Department of Natural Resources Geological Survey Bureau, 109 Trowbridge Hall, Iowa City, Iowa 52242-1319
Search for other works by this author on:
Published:
January 01, 1996

Impact cratering is a geological process that is still rather unappreciated by the geological community, despite the fact that on all other planets and satellites with a solid surface impact cratering is the most important surface-modifying process. About 150 impact structures have been recognized on Earth to date. To put the studies of the Manson crater in a proper framework, we review some fundamental principles of impacts and how to recognize impact craters. The formation conditions of impact craters lead to pressure and temperature conditions in the target rocks that are significantly different from those reached during any internal terrestrial processes. Among the most characteristic changes induced by the impact-generated shock waves are irreversible changes in the crystal structure of rock-forming minerals, such as quartz and feldspar. These shock metamorphic effects are characteristic of impact and do not occur in natural materials formed by any other process. For comparison with Manson, we give an overview of our current knowledge of impact structures in the United States of America, which include confirmed, probable, and possible structures and a few other features for which an impact origin has been suggested. Based on the discovery of remnants of meteoritic matter and/or shock metamorphic effects in the crater rocks (which we accept as criteria to confirm an impact origin), we classify 20 craters in the United States of America as confirmed impact structures. Unfortunately, we have to conclude that about half of these structures are not well studied, even though they are relatively accessible.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

The Manson impact structure, Iowa; anatomy of an impact crater

Christian Koeberl
Christian Koeberl
Search for other works by this author on:
Raymond R. Anderson
Raymond R. Anderson
Search for other works by this author on:
Geological Society of America
Volume
302
ISBN print:
9780813723020
Publication date:
January 01, 1996

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal