Though stratigraphic correlations are abundant in the Cordilleran basin-fill, they rarely include along-strike transects providing a spatio-temporal sense of deformation, sediment-supply and subsidence. A new, high-resolution, regional strike-correlation of the Castlegate Formation reveals progressive northward-growth of the San Rafael Swell during two embryonic episodes of Laramide-style deformation in central Utah. The intrabasinal deformation-events produced gentle lithospheric-folding punctuated by erosional-truncation of upwarped regions. The earliest episode occurred at 78 Ma in the southern San Rafael Swell likely causing soft-sediment deformation and stratal-tilting. Following this the alluvial-plain was leveled and rapid, extensive-progradation took place. A second episode, at 75 Ma, where deformation was focused in the northern San Rafael Swell, also caused sediment-liquefaction and erosional beveling. The stratal-tilting and sediment-liquefaction is attributed to seismicity induced by basal-traction between a subducting flat-slab and continental-lithosphere. The south-to north time-transgression of uplift is spatio-temporally consistent with NE-propagation of an oceanic-plateau subducted shallowly beneath the region.
| Identifer | oai:union.ndltd.org:uno.edu/oai:scholarworks.uno.edu:td-3217 |
| Date | 13 May 2016 |
| Creators | Cross, David B |
| Publisher | ScholarWorks@UNO |
| Source Sets | University of New Orleans |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of New Orleans Theses and Dissertations |
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