Late Jurassic to Early Cretaceous black shale formation and paleoenvironment in high northern latitudes: Examples from the Norwegian-Greenland Seaway
Article first published online: 19 SEP 2003
Copyright 2003 by the American Geophysical Union.
Volume 18, Issue 3, September 2003
How to Cite
2003), Late Jurassic to Early Cretaceous black shale formation and paleoenvironment in high northern latitudes: Examples from the Norwegian-Greenland Seaway, Paleoceanography, 18, 1074, doi:10.1029/2002PA000867, 3., , , and (
- Issue published online: 19 SEP 2003
- Article first published online: 19 SEP 2003
- Manuscript Accepted: 14 APR 2003
- Manuscript Revised: 14 FEB 2003
- Manuscript Received: 25 NOV 2002
- black shale formation;
- depositional environment;
- Norwegian-Greenland Seaway;
- organic petrography
 The Late Jurassic to Early Cretaceous (Volgian-Ryazanian) was a period of a second-order sea-level low stand, and it provided excellent conditions for the formation of shallow marine black shales in the Norwegian-Greenland Seaway (NGS). IKU Petroleum Research drilling cores taken offshore along the Norwegian shelf were investigated with geochemical and microscopic approaches to (1) determine the composition of the organic matter, (2) characterize the depositional environments, and (3) discuss the mechanisms which may have controlled production, accumulation, and preservation of the organic matter. The black shale sequences show a wide range of organic carbon contents (0.5–7.0 wt %) and consist of thermally immature organic matter of type II to II/III kerogen. Rock-Eval pyrolysis revealed fair to very good petroleum source rock potential, suggesting a deposition in restricted shallow marine basins. Well-developed lamination and the formation of autochthonous pyrite framboids further indicate suboxic to anoxic bottom water conditions. In combination with very low sedimentation rates it seems likely that preservation was the principal control on organic matter accumulation. However, a decrease of organic carbon preservation and an increase of refractory organic matter from the Volgian to the Hauterivian are superimposed on short-term variations (probably reflecting Milankovitch cycles). Various parameters indicate that black shale formation in the NGS was gradually terminated by increased oxidative conditions in the course of a sea-level rise.