ONTARIO PETROLEUM INSTITUTE

Stratigraphy and Depositional Environments of Niagaran Carbonates, Bruce Peninsula, Ontario 2002

The Paleozoic geology of the Bruce Peninsula has been the subject of a multi-year mapping project by the Ontario Geological Survey (OGS) (Armstrong 1987, 1988, and 1989). The overall objective of this project was to produce a new series of 1:50,000 scale maps, incorporating updated stratigraphic terminology and new outcrop and subsurface information. A lithostratigraphic approach was emphasized in order to aid in the delineation and evaluation of potential bedrock resources such as building stone and crushed stone aggregate. A shallow drilling program conducted in 1989 and 1990 (Armstrong 1989, and in prep.) has helped in elucidating the interrelationships among the uppermost Silurian units. Despite this recent activity, the Paleozoic strata of the Bruce Peninsula remain understudied especially with respect to current depositional and diagenetic models and concepts.

The purpose of this field trip is to examine the Silurian outcrop belt of the Bruce Peninsula. This succession is considered to be the shelfward equivalent of the hydrocarbon producing horizon, commonly termed the "Niagaran Play", in the subsurface of northern and southern Michigan and southwestern Ontario (Figure 2). As discussed in the next section, this ongoing play has been one of the most successful onshore North America exploration and development ventures of the past three decades. This field trip will focus on lithofacies recognition, in this almost entirely dolomitized succession, in environments ranging from shallow high energy carbonate sand shoals to deeper (?) environments with better developed bioherms and better facies differentiation.

By Derek K. Armstrong, Wayne R. Goodman and Mario Coniglio

Trenton - Black River Group Carbonates Core Workshop - 2001 (CD)

The Trenton Group (Middle Ordovician) carbonates of the Michigan Basin have been the subject of re-evaluation over the last two decades. The lower Paleozoic rocks located beneath Essex and Kent Counties within southwestern Ontario have been the focus of exploration for oil and gas. These structurally controlled oil fields are interpreted to have formed from a regional fracture network that provided conduits for dolomitizing fluids and assisted with hydrocarbon migration and emplacement (Sandford 1985; Taylor and Sibley 1986; Hurley and Budros 1990; Budai and Wilson 1991; Middleton 1991; Colquhoun 1991). The resulting linear fields have dimensions that range from a few hundred metres wide and several kilometres long, such as the case in Ontario, to several orders of magnitude larger, observed in the Albion-Scipio and Stoney Point oil fields within central Michigan (Figure 1). Similar reservoir characteristics have been described from oil fields in New York, Ohio and Indiana (Keith 1988b).

By Ian M. Colquhoun, Ph.D.

Carbonate Cores of the Middle Ordovician Trenton and Black River Groups of Southwestern Ontario

The Trenton Group (Middle Ordovician) carbonates of the Michigan Basin have been the subject of re-evaluation over the last two decades. The lower Paleozoic rocks located beneath Essex and Kent Counties within southwestern Ontario have been the focus of exploration for oil and gas. These structurally network that provided the conduits for dolomitizing fluids and assisted with hydrocarbon migration and emplacement (Sanford 1985; Taylor and Sibley 1986; Hurley and Budros 1990; Budai and Wilson 1991; Middleton 1991; Colquhoun 1991). The resulting linear fields have dimensions that range from a few hundred meters wide and several kilometers long, such as the case in Ontario, to several orders of magnitude larger, observed in the Albion-Scipio and Stoney Point oil fields within central Michigan (Figure 1). Similar reservoir characteristics have been described from oil fields in New York, Ohio and Indiana (Keith 1988b).

By Ian M. Colquhoun, Rubicon Petroleum Inc. & Robert A. Trevail, Orion Resources Consulting Ltd.

Depositional Environments and Paleoecology of Middle and Upper Devonian
Strata in Southwestern Ontario.

Rocks of this succession not only support a number of hydrocarbon and mineral industries, but also contain spectacularly preserved invertebrate fossils that are sought by collectors the world over. Legend has it that James Hall was so impressed by a specimen of Mucrospirifer thedfordensis collected near Arkona, that he offered five cents for each complete specimen sent to him. Men working on a railway line through the Widder Formation near Thedford were delighted to learn of Hall’s offer and sent him an apple barrel full of specimens! Understandably, Hall took back his original offer.

By Cameron J. Tsujita, Department of Earth Sciences, The University of Western Ontario & Denis K. Tetreault, Department of Earth Sciences, The University of Western Ontario (with illustrations by Cameron J. Tsujita)

Subsurface Geology of Southwestern Ontario - Core Workshop

A major structural high known as the Algonquin Arch trends northeasterly through the middle of the southern Ontario peninsula and forms a ridge separating the Michigan and Appalachian Basins (Fig.2). The arch existed as a basement high during deposition of Cambrian sediments and persisted throughout most of the Paleozoic Era. It had a controlling influence on later patterns of sedimentation throughout southwestern Ontario, resulting in thinning, facies changes, pinchouts, and erosional truncation of stratigraphic units as they approach and pass over the arch. Where the Algonquin Arch meets the notherly trending Findlay Arch there is a structural depression known as the Chatham sag. To the northeast the Frontenac Arch forms the pinchout margin of the sedimentary section of southwestern Ontario.

By Terry R. Carter

Gypsum Deposits and Stratigraphy of the Salina A and B Units, Algonquin Arch- Niagara Peninsula, Southwestern Ontario

The gypsum mines of southern Ontario are hosted by the Upper Silurian Salina Formation, located in the Niagara Peninsula on the eastern flank of the Algonquin Arch (Fig. 1). During the Upper Silurian, the Algonquin Arch formed a positive area between the Appalachian (Allegheny) and Michigan Basins (Sanford, 1969). Three mines are presently in operation: Domtar Construction Materials (Domtar) at Caledonia, Westroc Industries (Westroc) at Drumbo, and Canada Gypsum Company at Hagersville. Domtar and Westroc are both situated within the Salina Formation A and B Units. The Canada Gypsum Company deposit is believed to be in the Salina Formation D or E Units.

By Simon J. Haynes and Joy Hughes-Pearl

Stratigraphy, Sedimentology and Biostratigraphy of Ordovician Rocks of the Peterborough- Lake Simcoe Area of Southern Ontario

Middle Ordovician strata exposed in the Peterborough- Lake Simcoe area of central Ontario have been studied for near a century and a half, and rank among the more intensely studied stratigraphic successions in Canada. Early reports on the Paleozoic sequence in southern Ontario date from the mid-1800’s (e.g., Murray 1843) and the first maps of the Lake Simcoe area were published by Johnson in the early 1900’s (e.g., Johnson 1908, 1912). Subsequent mapping by the Geological Survey of Canada half a century later (e.g., Winder 1954, 1955; Liberty 1969) and more recently by the Ontario Geological Survey ( Carson 1981a, LeBaron and Williams 1990) has led to an increased appreciation of the complexity of the Middle Ordovician strata of the Black River and Trenton groups with regards to their lithostratigraphy and biostratigraphy. Most recently, these strata have been examined in light of contemporary facies and diagenetic models (e.g., Wilkinson et al. 1982, Brett and Brookfield 1984, Brookfield 1988, Brookfield and Brett 1988, Noor 1989).

By M. Coniglio, M.J. Melchin and M.E. Brookfield

Bedrock Geology and the Precambrian-Paleozoic Unconformity in Southeastern Ontario

Due to its location on a structural arch and the consequent thinness of the Paleozoic cover rocks, southwestern Ontario is a uniquely favourable location for the study of the Precambrian basement rocks in the eastern mid-continent of North America. Middle Proterozoic rocks of the Grenville Province outcrop to the northeast of Toronto and can be traced southwestward beneath the cover sequence utilizing drillhole data and gravity and aeromagnetic maps (e.g. Carter and Easton, 1990).

By R.M. Easton, T.R. Carter and G. Di Prisco