1. Petroleum Geochemistry Program, Department of Geology P.O. Box 1047 Blindern, N-0316 Oslo 3, Norway
2. Chevron Texaco Norway AS Karenslyst Alle 2, P.O. Box 97, N-0212 Oslo, Norway
3. Enterprise Oil Norge Ltd. P.O. Box 399, N-4001 Stavanger, Norway A/S Norske Shell P.O. Box 40, N-4098 Tananger, Norway
4. Statoil Research Centre Trondheim, N-7005 Trondheim, Norway
5. Institute of Petroleum and Organic Geochemistry Forschungszentrum Jülich D-52425 Jülich, Germany