[1] Geosci Australia, Canberra, ACT 2601, Australia
[2] Alberta Energy & Util Board, Edmonton, AB T6B 2X3, Canada
[3] Bur Rech Geol & Minieres, CDG, DIR 3, F-45060 Orleans, France
[4] US Geol Survey, Natl Ctr, Reston, VA 20192 USA
[5] British Geol Survey, Keyworth NG12 5GG, Notts, England
[6] Geol Survey Denmark & Greenland GEUS, DK-1250 Copenhagen K, Denmark
[7] Norwegian Petr Directorate, N-4003 Stavanger, Norway