Stratigraphy and Facies of the Middle Devonian, Dundee Formation, Southwestern Ontario

Abstract

<p> The Middle Devonian Dundee Limestones of Southwestern Ontario accumulated in the Michigan and Appalachian Basins, with deposition in part being controlled by the proximity to the Findlay and Algonquin arches. Six lithofacies were recognized in the Dundee Formation during detailed core and outcrop studies . Stratigraphic relations indicate that, prior to deposition of Dundee carbonates, a major regression exposed underlying Detroit River sediments adjacent to the arches. Subsequent transgression deposited reworked sands and shallow shelf, bioclastic limestones in most areas of the adjoining basins while in westernmost regions of the Appalachian Basin Columbus Formation sediments were accumulating adjacent to the Findlay Arch. </p> <p> Transgression became interrupted during middle Dundee time and a thick unit of lagoonal muds was deposited in the Appalachian Basin. A regionally well-developed firmground capping these mudstones indicates that a significant episode of non-deposition ensued. The equivalents of these muds in the Michigan Basin are pulses of coarse, reworked grainstones and rudstones indicating that substrates there were shallower and above wave base. Evidence of subsequent renewed transgression is preserved as middle to outer shelf moderately fossiliferous mudstones and wackestones overlying shallow shelf facies. </p> <p> Many friends, too many to mention here, made my stay at McMaster an enjoyable one. Mac wouldn't have been the same without the numerous challenges and imaginative adventures in which these people were always willing to participate. Francois Brissette, Bruce Willmer, Randy Meecham, Stu Miller, Steve Beneteau and other members of the Rockbusters Football and Aureoles Baseball teams provided continuous entertainment both on and off of the sports field. Their dedication and light-hearted approach allowed me to maintain a respectable degree of sanity throughout my studies. </p> <p> Finally, I would like to thank my family for their continual assistance, encouragement and support provided during the pursuit of my academic endeavours. </p>