Paleomagnetism in the Western Canada Sedimentary Basin: Dating fluid flow and deformation events

The impetus provided by Lithoprobe's Alberta Basement Transect program has led to a tenfold increase in paleomagnetic data for strata in the Western Canada Sedimentary Basin (WCSB). This paper aims to provide a synthesis of this research with emphasis on the results to date. They show that paleomagnetic methods can be used to reliably: (1) date dolomitization in the strata, in petroleum reservoirs, and in Mississippi Valley-type (MVT) zinc-lead hydrothermal ore deposits; (2) narrowly constrain the ages of folding and faulting events; and, (3) orient stored core for further geologic analysis to provide other useful geologic information. Except for a few specimens in anhydrite and a few more in limestone that retain a primary remanence, all of the few thousand specimens from a few hundred sites in dolomites and zones of MVT mineralization throughout the WCSB define ages corresponding to the time span of the Laramide Orogeny. Thus, they support geologic models that attribute dolomitization, MVT mineralization and, by inference, related geologic phenomena to regional fluid flows spawned by Laramide orogenesis.