The Gething and Bluesky Formations of Alberta and northeast British Columbia record the early paralic infill of the Western Canadian Sedimentary Basin. Gething sediments comprise a thick alluvial accumulation of cross bedded sandstones, rooted mudstones and coals which are representative of low energy, thin, narrow, laterally discontinuous meanderbelt sandstones and overbank deposits. Towards the top of the Gething Formation there is an abrupt change in alluvial architecture to thicker, multi-storey, cross bedded sandstones which are capped by bioturbated, silty mudstones. These sandstones have excellent connectivity and are developed within linear, erosively based scours which are several kilometers in width and tens of kilometers in length and are interpreted as fluvio-estuarine incised valley fills. Immediately downdip are progradational packages of shales and sandstones of the Bluesky Formation which are organized into northward offlapping and complexly organized deltaic successions.
During the southward advance of the Boreal Sea, Gething fluvial valleys were flooded and consequently erosively widened and deepened to form an embayed coastline. During stillstands or periodic regressive phases, valleys were eventually backfilled with fluvio-estuarine sediments allowing the subsequent progradation of northward offlapping Bluesky deltas. Renewed rise of relative sea level drowned the shoreline and its deltaic promontories and moved the coastline southward. Individual parasequences contain systems tracts comprising incised valley fills passing downdip to deltaic successions. Parasequences erosively overlie alluvial fill and are in turn are erosively overlain by marine transgressive deposits. Regionally, these successions are organized into a retrogradational parasequence set which backsteps several hundred kilometers.
The sequence stratigraphic framework in conjunction with hydrodynamic and production analysis allows the development of an exploration/exploitation model that predicts systems tract development, reservoir performance and pool segregation.