Geology of the Copenhagen Canyon area, Monitor Range, Eureka County, Nevada

Abstract

Rocks of an eastern miogeosynclinal and a western eugeosynclinal assemblage have been thrust into juxtaposition in the western portion of the Copenhagen Canyon area. In the eastern portion of the area, only rocks of the eastern assemblage are present. The eastern assemblage is composed predominantly of clastic limestones ranging in age from Lower Ordovician to Helderbergian. The western assemblage is represented by the Ordovician Vinini formation. Lower Pennsylvanian fusulinid-bearing rocks overlie the Vinini formation in the highest thrust plate and are considered part of the overlap assemblage. Four imbricate thrusts overlie the Helderbergian limestones, which have been severely deformed locally. Deformation is mild in the lower thrusts, but extreme in the uppermost thrust.