Notes on the stratigraphy, extent and tectonic implications of the Minkinfjellet Basin, Middle Carboniferous of central Spitsbergen

Abstract

A part of the Carboniferous basin stratigraphy, the clastic to carbonaceous Minkinfjellet “Member” of the Nordenskioldbreen Formation in Central Spitsbergen, is deposited in an asymmetric basin structure (here referred to as the Minkinfjellet Basin), similar to the underlying Ebbadalen Formation. The western boundary -situated within the Billcfjorden Fault Zone -has probably been a little farther east than during deposition of the Ebbadalen strata. The thickness attains ca. 350 m in central parts of the basin, and the strata strongly attenuates to the east and south. The base and top are interpreted as low-angle stratigraphical unconformities. The boundary with the overlying Cadcllfjellet Member of the Nordenskioldbreen Formation is locally disrupted by carbonate breccias of suggested earthquake origin. Formation rank is suggested for the sedimentary succession of the Minkinfjellet basin.