Open File Report 1993-26

Open File Report 1993-26

OFR 1993-26

Jurassic/Cretaceous Boundary in West Central Alberta

Author(s) Kramers, J.W. Dolby, G. Date 1993-11-01

The Jurassic/Cretaceous boundary in a well is important to both industry and government because it determines the stratigraphic limit of a company's oil and natural gas rights. In west Central Alberta this boundary is elusive because the only definitive way to locate it, is by the use of paleontology. This report, a cooperative effort between industry and government organizations, presents regional cross sections in which the location of the boundary has been defined using palynology, core studies and detailed correlations. The cross sections represent a grid of control wells that can be used to further detailed studies in local areas, such as that presented in the companion volume to this report, ARC Open File Report 1992-23.

The report discusses Jurassic stratigraphy, the nature of the Jurassic/Cretaceous boundary and includes nine regional cross sections, as well as the results of all 268 palynological analyses that were performed for this study. Because paleontological analysis is the only definitive method to locate this important boundary, this study recommends that in future, whenever possible, core is taken and palynological analyses performed to establish the exact location of the boundary. This will help both industry and government in defining the stratigraphic limit of oil and gas leases.