Produced in the Eastern Region, Reston, Virginia,
by John Watson and Kathie Fraser.
The original WordPerfect files were exported to HTML.
Figures were scanned from original copy.
U.S.Department of the Interior, U.S. Geological Survey
<https://pubs.usgs.gov/openfile/of98-487/contents.html>
Maintained by Dave Soller
Last updated 10.30.98