Ancient solution phenomena in the Madison Limestone (Mississippian) of north-central Wyoming

A karst topography was developed on the Madison Limestone of north-central Wyoming during the middle Meramecian early Chesterian time interval. Ancient karst features include enlarged joints, sinkholes, caves, and solution breccias that resulted from leaching of evaporitic beds in the upper 400 ft of the Madison bedrock. These features are predominantly phreatic rather than vadose. Most of the open spaces are fdled by sand and residual products reworked by the early Amsden sea, which transgressed the area during the Chesterian.