Graduate Thesis Or Dissertation


Subsurface Stratigraphy of the Upper Cretaceous Lower Williams Fork Formation, Piceance Basin, Northwestern Colorado Public Deposited

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  • The lower Williams Fork is divided into five informal intervals which consist largely of interbedded sandstones, siltstones, shales, and coal deposited in shoreface, river channel, overbank, crevasse-splay, and swamp settings. The lower Williams Fork was deposited within the highstand-systems tract of a third-order sequence. This HST is bounded by a maxmum flooding surface at the top of the underlying Cozzette (75.1 Ma) and a sequence boundary at the base of the overlying middle Williams Fork (73.5 Ma). The width of the coal zone in the lower coastal-plain varied through time from 30-40 km for intervals 1 and 3, to about 15-20 km for intervals 2 and 4. The differences in widths are likely associated with variation in accommodation.
Date Issued
  • 2012
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  • 2019-11-17
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