On February 13, 1947, a commercial oil pool, which may prove to be the largest in Canada, was discovered near the village of Leduc, Alberta. Production was found in two limestone-dolomite zones of Late Devonian age. Although structural relief is indicated, oil and gas accumulation is apparently due primarily to a stratigraphic trap created by coral-reef or bioherm development.
The ultimate oil reserves, areal extent, structural and stratigraphic configuration, and other data must await further development of the field.
The shallower discovery zone is an example of a “regressive type” of bioherm (coral reef), while the lower, but more prolific, zone is a “transgressive type”. These two types of bioherm development are discussed. Application of these principles to the Permian reef problem of West Texas and New Mexico is suggested.