Abstract

The Parsons Lake gas field is located on the southeastern margin of the Mackenzie Basin, within a zone of large down-to-basin normal faults that comprise the flank of the Aklavik Arch complex. Across the fault zone the Mesozoic and Cenozoic clastic section thickens rapidly and ultimately attains a thickness of 30,000 to 40,000 feet.

The stratigraphic column in the Parsons area is comprised of Paleozoic carbonates with minor clastics, Upper Jurassic and Cretaceous marine shales containing coastal sandstone wedges, and Tertiary marine shales which grade upward into a complex of coal-bearing fluvio-deltaic clastics. The marine shales of the Upper Jurassic (Husky Formation) rest with regional angular unconformity on early to middle Paleozoic carbonates. Several other unconformities within the Cretaceous sequence add complexity to the stratigraphic succession.

The Parsons Sandstone of Early Cretaceous (Berriasian to Valanginian) age is the principal hydrocarbon reservoir in the Parsons Lake area. The quartzose sandstone is grossly subdivided into lower marine, middle non-marine and upper marine members which correspond closely with similar units occuring in the correlative Lower Sandstone and Coal-Bearing Divisions that outcrop in northern Richardson Mountains.

The local structure in the Parsons Lake Field consists of a rollover anticline associated with a large listric normal fault.