Back to U.S. Geological Survey Circular 1192 contents page
This back of title page is also available in pdf format: backtitle.pdf

U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY
Charles G. Groat, Director

Any use of trade, product, or firm names in this report is for identification purposes only and does not constitute endorsement by the U.S. Government.

Reston, Virginia 1999

For sale by U.S. Geological Survey, Information Services,
Box 25286, Federal Center,
Denver, CO 80225