A depositional model for the development of the Helvetiafjellet Formation in Nordenskiöld Land, Spitsbergen is presented. The formation was deposited into a segment of the large epicontinental Boreal basin that rimmed northern Pangaea during the Early Cretaceous. A wide range of depositional subenvironments are recorded within the succession; including fluvial braidplain, shallow marine bay, delta, coastal plain and fluvial channel. The depositional model approaches a layer-cake style for this part of the basin, caused by the rapid rates of progradation and retrogradation made possible by the gentle depositional gradient. An initial period of fluvial deposition arose in response to an early rise in relative sea-level. Following a regional flooding, the progradational to aggradational architecture in the area reflects a balanced rate of increase in accommodation vs. rate of sedimentation (A/S) ratio. This resulted in a heterolithic stacking of sandstone and mudstone. Autogenic variables are thought to have dominated the lateral facies variations recorded in the upper and middle parts of the succession.