The GEAT department welcomes Dr. Andrew Hutsky from the University of Mount Union as our next seminar speaker.
Title: Structural controls on sedimentation patterns in the Cretaceous Western Cordillera foreland basin, USA
When: Friday, April 13 @ 4:10 pm
Where: 152 Science Hall
Abstract: Structural forcing is increasingly being invoked to explain delta progradation in foreland basins. Nonetheless, the recognition of structural forcing and the consequences for the distribution of sediment often rely on incomplete data sets and indirect sequence stratigraphic criteria. This study on the Cenomanian–Turonian Frontier Formation of northern Utah, north-west Colorado and south-west Wyoming (‘Vernal Delta’) provides detailed facies and sequence stratigraphic analyses based on outcrop sections and wireline log suites from the Uinta, Piceance and Green River basins in order to evaluate potential structural forcing claims. Four intervals (Intervals 1-4) were defined and mapped by using regionally traceable stratigraphic horizons (flooding surfaces and sequence boundaries). In general, intervals 1-4 form a major basinward projection of coarse clastic strata generated in response to four separate, high-frequency sea-level regressions. Furthermore, a change through time from southward projection of elongate lobes (Intervals 1 and 2) to eastward dispersal and development of a broad, arcuate planform (Intervals 3 and 4) can be explained in terms of changes in prevailing tectonic forcing mechanisms. North–south trending Sevier Orogeny forebulge structures controlled Intervals 1 and 2. West–east progradation (Intervals 3 and 4) was probably controlled by Proterozoic basement lineament reactivation due to Laramide foreland uplifts (Uinta Mountains). These findings contribute to a more complete understanding of structural forcing of coastal to shallow marine successions in foreland basins and the tectonic evolution of the western USA.