Geologic image in the Kentucky Geological Survey data repository.Image Name: Grant Lake Limestone, Mason County Image Date: 4/2/2006 Category: photo_outcrop Source: Carey, Dan Format: JPG Size (MB): 0.8 Pixel Dimensions: 3292 x 1396 Description: Nearly all of Mason County is underlain by rocks composed of layers of limestone and shale. In general, when shale is predominant the terrain is rugged. When limestone is dominant, the terrain is more gentle and suitable for agriculture and development. Limestone forms steep cliffs along streams cutting from uplands to the river. Limestone and shale in the Grant Lake Limestone are exposed in this roadcut along U.S. 62/68. Photo by Dan Carey, Kentucky Geological Survey.