ABSTRACT

Within the Western Canada Sedimentary Basin, twenty different formation names have been assigned to the various facies of Triassic strata. For the purposes of the Atlas, four major subdivisions are recognized - Lower Triassic (Montney, Vega-Phospho), Middle Triassic (Halfway-Doig), Upper Triassic (Charlie Lake, and Baldonnel-Pardonet).

Various structural features are present, including drape over faults associated with the Peace River area block fault system and faulting related to the Laramide Orogeny.

Triassic sediments were deposited along a wave-dominated, tidally influenced coastline with a low relief interior. Four major sedimentary provenances are represented in outcrop and in the subsurface. These are:

1. Prograding deltaic clastics deposited on an extensive low angle shelf (e.g., Montney fms.).
2. Shoreline and prograding barrier island clastics (e.g., Halfway Fm.).
3. Sabkha - evaporite environmental system (e.g., Charlie Lake and lower Watrous fms.).
4. Shelf carbonate depositional system (e.g. Baldonnel Fm.).

The Triassic system includes abundant source rocks associated with the deltaic, barrier island and sabkha environments. Organic-rich Jurassic shales lie immediately above. Reservoir rocks occur in the deltaic, barrier island, sabkha and shallow water carbonate rocks. Traps are found associated with the various stratigraphic facies and structural elements within the system.

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