Jurassic Wanakah and Morrison Formations in the Telluride-Ouray-Western BlackCanyon Area of Southwestern Colorado

摘要

Several aspects of the Wanakah Formation and the basal part of the MorrisonFormation are discussed in the report. The Wanakah Formation and its subdivisions are correlated from the Wanakah mine area near Telluride and Ouray into western Black Canyon. As a consequence the Wanakah Formation in western Black Canyon is revised to agree with the formation in the Wanakah mine area. The relationship between the lower part of the Morrison Formation and the Wanakah Formation is described as is the areal distribution of gypsum in the two formations. The stratigraphic nomenclature and previous correlations of Jurassic rocks in the study area are reviewed. Finally, a reference section is established in western Black Canyon for the Wanakah Formation and the lower part of the Morrison Formation.