Library of Congress Cataloging in Publication Data
Trimble, Donald E.
The geologic story of the Great Plains.
(U.S. Geological Survey Bulletin 1493)
Bibliography: p. 50
Includes index.
Supt. of Docs. no.: I 19.3: 1493
I. Geology—Great Plains. I. Title.
II. Series: United States Geological Survey Bulletin 1493.
QE75.B9 no. 1493 [QE71] 557.3s [557.8] 80-607022
For sale by the Superintendent of Documents, U.S. Government Printing
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Washington, D.C. 20402