Department;
of;
Geosciences,;
University;
of;
Oslo,;
P.O.;
Box;
1047;
Blindem,;
N-0316;
Oslo,;
Norway.;
Department;
of;
Earth;
Science,;
University;
of;
Bergen,;
Allegaten;
41,;
N-5007;
Bergen,;
Norway.;
Present;
address:;
Eni;
Norge;
AS,;
P.O.;
Box;
101;
Forus,;
N-4064;
Stavanger,;
Norway.;
Present;
address:;
StatoilHydro,;
N-0246;
Oslo,;
Norway.;