The continental crust has grown through time with the addition of juvenile mantle derived material. Because of this, different domains of continental crust that formed at different times have contrasting Nd isotopic signatures. The Nd isotopic signature of continental crust can be translated to a Nd “Model Age,” reflecting the average timing of crustal growth.

Nd isotopic signatures in elastic sediments remain largely undisturbed during deposition and burial. Thus, Nd isotopic signatures of sediments record average crust formation ages in the sediment source areas and: provide a record of sediment provenance. Variations in Sm-Nd provenance signatures can be accurately traced vertically through a sedimentary sequence.

On the Norwegian Shelf, a huge database of Nd isotopic data has been gathered on Triassic through Palaeocene strata. This has been complemented by analyses of river sediments from onshore Britain, Norway: and E. Greenland, to delineate variations in Nd isotopic signatures of possible sediment source areas. Following pilot studies in the mid -80s, Nd isotope stratigraphy has been successfully applied as a detailed reservoir correlation tool in barren fluvial sequences, such as the Lower Jurassic Staffjord Fm. within the Snorre, Gullfaks and Visund fields. With a rapidly expanding database, Nd isotope stratigraphy has grown into a powerful tool for both fieldand basin scale correlation and provenance studies, in Triassic to: Palaeocene strata along the entire Norwegian shelf. The presentation will give a brief introduction into the Nd isotopic systematics of sedimentary rocks. followed by examples of applications in reservoir management and exploration.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah