1. Princeton University, Princeton, New Jersey 08540
2. Lamont-Doherty Geological Observatory, Columbia University, Palisades, New York 10964
3. University of California, San Diego, La Jolla 92037
4. U.S. Geological Survey, San Diego, California
5. Case Western Reserve University, Cleveland, Ohio 44106
6. University of California, Santa Cruz 95060
7. Cities Service Oil Company, Tulsa, Oklahoma 74101
8. Academy of Sciences, Moscow, U.S.S.R.
9. University of California, San Diego