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This study area encompasses a group of five large drumlins in the Westover - Strabane drumlin field section of the Flamborough Plain physiographic region.
The drumlins, comprised of Wentworth Till, rise to an elevation of some 295 m, some 40 m above the inter-drumlin valleys. During two stages of the last glaciation these high hills formed islands in proglacial lakes. Wave-action in these lakes modified the drumlins which now exhibit distinctive shoreline features, including wave-cut benches and wave-built gravel bars.
These features are best-developed on the southern drumlins which were exposed to waves generated across the open water to the south. Erosion features on the southern side of the drumlins include wave-cut benches and bluffs. Depositional features consist of wave-built sand and gravel bars and cones.
The most interesting feature is a tombolo, a gravel bar created between two islands. This feature was created by a combination of erosion of material from the exposed southern drumlin, and deposition of this re-worked material on the sheltered northern side. The result of this process is a bevelled drumlin joined to a second drumlin by a tombolo bar.
Mapping of the present elevations of the stranded shoreline features on these and other drumlins scattered throughout northern Hamilton-Wentworth Region and vicinity permits scientists to unravel the chronology of events in this region during part of the last glaciation period. The following information is based on information presented in Karrow and the ANSI summaries.
The highest shoreline features, at a present elevation of 275 to 277 m, have been attributed to Lake Whittlesey, an extensive lake formed between the Ontario ice lobe and the Paris Moraine some 13,000 years b.p. (Port Huron Stadial). A second set of shoreline features, at about 265 m elevation, have been assigned to Lake Warren, which existed about 12,700 years ago and reached its northern limit near this site. A third set of shoreline features at about 262 m elevation, may represent a lower Lake Warren strand line.
The unique combination of features at this site has been identified as representative of Lakes Whittlesley and Warren in the Erie basin. This area has been used as an earth science interpretative site by universities and various geological organizations. [Heagy 1993]
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