Multiple fluid flow events and the formation of saddle dolomite: examples from Middle Devonian carbonates of the Western Canada Sedimentary Basin

Saddle dolomite has been described from numerous Devonian carbonate reservo irs in Alberta and British Columbia. Its presence has been used as an indic ator of the interaction of high-temperature hydrothermal fluids with host c arbonates due to tectonic influences in the Western Canada Sedimentary Basi n. The timing of the fluid flow events that precipitated the saddle dolomit e and the chemistry of these fluids have been the basis of many arguments. Some researchers believe that the saddle dolomite was precipitated during t he Late Devonian to Carboniferous while others contend that the fluid flow event was during the Late Cretaceous to Early Tertiary. In this study, we c onducted a geochemical comparison between the Middle Devonian Sulphur Point and Slave Point carbonates from northwestern Alberta. The results demonstr ate the presence of both an early fluid flow events associated with the Lat e Devonian to Mississippian Antler Orogeny as well as a later event coincid ent with the Late Cretaceous to Early Tertiary Laramide Orogeny. (C) 2000 E lsevier Science B.V. All rights reserved.