189 Stratigraphy (Posters) II
IDENTIFICATION OF SUBTLE TECTONIC SIGNATURES IN NON-MARINE STRATA UTILIZING REGIONAL CROSS-SECTION CONSTRUCTION
Paper number: 189-10
Program: Technical Sessions
Time: 1:30 PM – 5:30 PM
Authors
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Anton F. WroblewskiUniv of Illinois-Chicago, Chicago, IL
Abstract
An example of such a succession is within the Upper Cretaceous Castlegate Formation in the Book Cliffs of Utah. There, a succession of fluvial/estuarine strata can be traced basinward into time-equivalent open marine strata. Regional cross-sections utilizing a flooding surface datum would indicate significant relief on the unconformity (~100 m) at the top of the succession, just below the Bluecastle Tongue. Accompanying this relief is variable thickness in the middle Castlegate interval from 50 m up to approximately 160 m. An alternative reconstruction using the unconformity as a datum suggests that the thickness changes are related to folding associated with uplift on the San Rafael Swell. This type of reconstruction would indicate beveling of the fold crest with subsequent deposition of the Bluecastle Tongue.