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Uranium in the Cochetopa District, Colorado, in relation to the Oligocene erosion surface

Jerry Chipman Olson
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Abstract

In the Cochetopa district, Colorado, the sequence of Mesozoic and Cenozoic events is as follows: development of a relatively smooth, planar erosion surface in Jurassic time; deposition, on this surface, of the Junction Creek Sandstone and Morrison Formation of Jurassic age, followed by deposition of the Dakota Sandstone and Mancos Shale of Cretaceous age; Laramide tilting and faulting; erosion to form a terrane of moderate relief in Oligocene time; deposition of lava flows and volcanic breccia of intermediate composition and of ash-flow tuff, all of Oligocene age; and subsequent erosion and canyon-cutting by Cochetopa Creek, a superimposed stream, and its tributaries.

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Jerry Chipman Olson. 1976. Uranium in the Cochetopa District, Colorado, in relation to the Oligocene erosion surface. https://doi.org/10.3133/ofr76222

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