1. Elf Aquitaine, Paris, France
2. Lockheed Missiles and Space Company, Inc., 3251 Hanover Street, Palo Alto, California 94304-1191
3. Engineering Geoscience, University of California, 414 Hearst Mining Bldg., Berkeley, California 94720
4. Lawrence Berkeley Laboratory, Earth Sciences Division 50E, Berkeley, California 94720