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 C anada Sedimentary Basin (WCSB). This paper aims to provide a synthesis of t his research with emphasis on the results to date. They show that paleomagn etic methods can be used to reliably: (1) date dolomitization in the strata , in petroleum reservoirs, and in Mississippi Valley-type (MVT) zinc-lead h ydrothermal ore deposits; (2) narrowly constrain the ages of folding and fa ulting events; and, (3) orient stored core for further geologic analysis to provide other useful geologic information. Except for a few specimens in a nhydrite and a few more in limestone that retain a primary remanence, all o f the few thousand specimens from a few hundred sites in dolomites and zone s of MVT mineralization throughout the WCSB define ages corresponding to th e time span of the Laramide Orogeny. Thus, they support geologic models tha t attribute dolomitization, MVT mineralization and, by inference, related g eologic phenomena to regional fluid flows spawned by Laramide orogenesis.