Enlighten
Research publications by members of the University of Glasgow
home > services > Enlighten

Regional distribution of diagenetic carbonate cement in Palaeocene deepwater sandstones: North Sea

Stewart, R.N.T., Haszeldine, R.S., Fallick, A.E., Wilkinson, M., and Macaulay, C.I. (2000) Regional distribution of diagenetic carbonate cement in Palaeocene deepwater sandstones: North Sea. Clay Minerals, 35 (1). pp. 119-133. ISSN 0009-8558 (doi:10.1180/000985500546521)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1180/000985500546521

Abstract

Sandstones of the Palaeocene Montrose Group were deposited in a deepwater fan environment, and form a major oil reservoir in the North Sea. Calcite concretions occur commonly within thick- bedded and structureless sandstones. These concretions have been identified by sonic logs and well reports, and were cross- checked with available core data. Regionally, 101 wells have been examined and carbonate concretions form 0.6-7.2% of the core. Concretions are most abundant along the flank of the Fladen Ground Spur, the north Witch Ground Graben (WGG), the east south Viking Graben and East Central Graben (ECG). Concretions of the ECG formed at deep burial, with C from decarboxylation. Geochemical inheritance of Mn and Sr from Cretaceous chalk clasts may occur. Concretion growth may also have been influenced by vertical expulsion of fluids (leak-off) localized above salt tectonics. Isotopic and petrographic evidence indicates that much carbonate C in the WGG was derived from biodegradation of migrating oil in meteoric water at shallow depth. The locations of abundant carbonate with characteristic negative C isotope signatures can be used as shallow exploration guides to leak-off points located above deep overpressured structures.

Item Type:Article
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Fallick, Prof Anthony
Authors: Stewart, R.N.T., Haszeldine, R.S., Fallick, A.E., Wilkinson, M., and Macaulay, C.I.
Subjects:Q Science > QE Geology
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Clay Minerals
ISSN:0009-8558

University Staff: Request a correction | Enlighten Editors: Update this record