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Authors

Charles Keyes

Document Type

Research

Abstract

Of all geological phenomena represented in Iowa those illustrating volcanic action are the rarest. Although we already know of the presence of very ancient lava-flows, which are disclosed in deep-well drillings, these are associated with rocks very much older than any outcropping in the state. These are the Keewenawan porphyries of the Northwest. From that very ancient date to the present there is not the slightest sign of volcanic activity discernible in all our very full geologic record. The finding, a short time ago, in the city of Des Moines, of very considerable beds of typical volcanic ash is therefore a circumstance of more than passing interest.

Publication Date

1921

Journal Title

Proceedings of the Iowa Academy of Science

Volume

28

Issue

1

First Page

49

Last Page

53

Copyright

©1921 Iowa Academy of Science, Inc.

Language

en

File Format

application/pdf

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