NJG75-1-04
1995
A Mid-Carboniferous,carbonate-dominated platform,Central Spitsbergen
75
1
pp. 48-63

The Minkinfjellet Member of the Nordenskiöldbreen Formation was deposited in a narrow, asymmetric rift basin - the Billefjorden Trough. The member represents the lower part of a major transgressive systems tract, and progressively onlaps the Nordfjorden Block to the west and the northem part of the Ny Friesland Block to the northeast of the trough. In the western part of the trough the lower part of the member shows a retrogradational interfingering with the upper part of the Ebbadalen Forrnation, although episodic, local progradation was caused by tectonic movements along the Billefjorden Fault Zone. The Nordfjorden Block was eventually transgressed in late Moscovian to early Kasimovian time, and the lower part of the Cadellfjellet Member forms the upper part of the transgressive tract. Parasequences are represented by shallowing-upward cycles bounded by transgressive surfaces. The parasequences are formed by: (2) Restricted, shallow subtidal to intertidal dolomites grading upwards into intertidal to supratidal evaporites, and (2) platform dolomudstones grading upwards into shallower, grain-supported limestones capped by subaerial exposure surfaces. Solution collapse breccias of more than 100 m thickness forrned during the subaerial exposures. Water was probably derived from the Nordfjorden Block and the breccias are restricted to the eastern margin of the block.

0029-196X