The lands surrounding the lake are part of the Canadian Shield, the largest single exposure of Precambrian rocks in the world which were formed after the Earth's crust cooled. The hills in the Temagami area are remnants of the oldest mountain range in North America that date back during the Precambrian era. These heavily eroded mountains would have rivaled the Himalayas in grandeur. The uplifting was accomplished as enormous pressure caused the earth to buckle in a process called folding. Other processes, such as volcanic activity and geologic faulting in which the earth cracks open also contributed to the formation of these mountains. Over millions of years, these enormous mountains were gradually eroded to the land we know today in Temagami. While Rabbit Lake is a fairly quiet lake dotted with cottages, the forest is continually logged and the threat of mining is looming ever closer with the discovery of kimberlite, a volcanic rock notable as a diamond indicator. This in turn forms part of the Temagami Greenstone Belt, an Archean greenstone belt characterized by felsic-mafic volcanic rocks.