Late precambrian sedimentation in the central sparagmite basin of south Norway

Late Precambrian (Eocambrian) sediments of south Norway, the so-called 'sparagmite sequence', consist of 1500-3000 m of graywackes, shales, arkoses, carbonates, and conglomerates. A system of coarse clastic wedges deposited as fan deltas are found along the margin of the basin, suggesting that sedimentation took place in well-defined grabens as a response to faulting. The Moelv Tillite is developed both as a massive diamictite and as a drop-stone facies in a laminated matrix, indicating local glaciations around the basin. The sparagmite basin is interpreted as a rift valley structure related to the opening of the protoatlantic ocean. The late Precambrian rifting phase was followed by the Lower Cambrian and Middle Cambrian transgression.