t the Wisconsin Glaciation was the last of four major glaciation periods but evidence of previous glaciation is very rare in Ontario, and may be disregarded when describing landforms in the region (Otonabee Region Conservation Authority, 1983, p. 2-1). Boyce and Eyles (1991, p.787) describe the Peterborough drumlin field as “the largest in central Canada, (and) contains more than 3000 drumlins on the northern margins of Lake Ontario.” Most of the drumlins are less than 1.6km long and 0.4kn wide and the average height of 23 meters. They also average 6 to 8 drumlins per square kilometer. (Otonabee Region Conservation Authority, 1983, p. 2-4) As the field study progressed it became apparent that while drumlins have been extensively studied their origins are still subject to disagreement and controversy (Boyce and Eyles, 1991, p.787). A particularly interesting relationship between drumlin shape and drift thickness was made by Boyce and Eyles (1991, p. 788):“This shows a systematic decrease in drumlin length/width ratios, from narrow, elongate forms in the north where drift thickness is reduced, to much larger, ovoid drumlins in southern areas of thick drift cover.” Another relationship touched upon by Boyce and Eyles (1991, p.789) was the asymmetrical and ovoid shape of the southern drumlins reflects the decreased time available for streamlining by the glacier. While different types of drumlins were difficult to identify in the field, the three main types of drumlins are present in the Peterborough drumlin field and are described as “a) those composed primarily of rock (rock drumlins); b) those formed from pre-existing drift (erosional drumlins); and c) those formed of till or mixtures of till and minor amounts of stratified material (depositional drumlins).” (Otonabee Region Conservation Authority, 1983, p. 2-3) Erosional drumlins are identified as the most common in the Peterborough drumlin fi...
