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1963: Geologist, Tenneco Oil Company, Casper, WY
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1963–65, 1969–1970: Teaching Assistant, Dept. of Geological Sciences, Univ. of Texas at Austin
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1965–69: Owner & operator of retail business
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1968–69, 1971–present: Professor (since 1977) Department of Geological Sciences, San Diego State University, San Diego, CA1984: Visiting Professor, University of Canterbury , Christchurch , New Zealand
