Pennsylvanian and Permian Stratigraphy of the Elk Range, Colorado, Preliminary Report [Abstract]

Sections have been measured at Crystal River Ranch, Thompson Creek, Mount Sopris, Coal Creek and Schofield Park. Maroon and Gothic formation can be recognized in all but the Coal Creek section. The Belden shale is, however, unexposed in these sections. Incomplete sections of Gothic at Crystal River Ranch and Thompson Creek include large amounts of gypsum. At Mt. Sopris, however, only 60 feet of gypsum is present and none was observed at Schofield Park. The Maroon formation increases in thickness from approximately 1900 feet at Glenwood Springs to a maximum of about 7100 feet at Crystal River Ranch. Thereafter it thins rapidly to only 1200 feet at Schofield Park. Several limestones occur within the Maroon between Mt. Sopris and Glenwood Springs but are not present to the south.