In the Peace River oil sands deposit an estimated 75 billion bbl of heavy oil are trapped at the updip pinch-out of the Lower Cretaceous Bluesky and Gething Formations, at depths of 1,500 to 2,500 ft (457 to 762 m). The principal oil-saturated sand body occurs near the updip edge of the reservoir and averages 80 to 100 ft (24 to 31 m) in thickness. Downdip, the Gething Formation thickens to over 250 ft (76 m) but becomes mainly shale with a few thin sands. Throughout the area it is capped by thin marine sands of the Bluesky Formation. Based upon palynology and sedimentary structures, this sequence grades upward from continental through brackish to marine.

Sedimentary structures of a channel sequence are clearly displayed in the main sand body. From bottom to top the sequence is: a channel lag deposit containing abundant disoriented detrital carbonaceous fragments, plane-bedded or structureless sand, large scale cross-bedded sand, smaller scale cross-bedded sand, and structureless or bioturbated sand containing abundant glauconite. Laterally this sequence commonly grades into thinly interbedded oil-saturated sand and shale.

Reservoir properties vary between the facies. The channel lag deposits have coarser grain size, less interstitial

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clay, and generally lower oil saturations than the thinly interbedded sand and shale. The cross-bedded sands contain the highest oil saturations and form the largest and most continuous reservoir. Oil saturations are commonly lower in the marine sands of the Bluesky Formation where glauconite, clastic carbonate, and local carbonate cement combine to reduce porosity and permeability.

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