Upper Carboniferous cyclic shelf sedimentation, North Greenland and the Barents Sea

Lars Stemmerik

The Upper Carboniferous (Moscovian-Gzelian) successions in North Greenland and the western Barents Sea form a second order transgressive-regressive sequence related to mid-Carboniferous rifting in the region. The transgressive, Moscovian succession consists of eight 3rd order depositional sequences that internally are composed of cyclic shelf deposits dominated by carbonates, mixed carbonates-siliciclastics and carbonates-evaporites. The 3rd order depositional sequences range in thickness from 40 m to more than 150 m. They are in most areas tabular and consist of stacked, 10-15 m thick and laterally widespread high frequency cycles. Locally, the 3rd order depositional sequences are wedge-shaped and the high frequency cycles are laterally restricted.

The transgressive part of the high frequency cycles is usually composed of biogenic wackestone or bioturbated siltstone. Maximum flooding is recorded by intensely bioturbated carbonate mudstones or wackestones while the highstand part of each cycle displays the greatest facies variations. In the laterally persistent cycles, the highstand deposits include biogenic packstones and grainstones, tabular algal dominated build-ups and shoreface sandstones and conglomerates. In the laterally restricted cycles carbonate build-ups dominate the highstand deposits. Individual cycles are capped by subaerial exposure surfaces in the platform areas. In more distal settings evaporite deposition took place during sea level lowstand.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California