(U-TH)/HE AND (U-PB) DOUBLE DATING CONSTRAINTS ON THE DYNAMIC INTERPLAY BETWEEN THRUST DEFORMATION AND BASIN DEVELOPMENT ALONG THE SEVIER FORELAND BASIN, UTAH

Despite several decades of evolving concepts of thrust belt mechanics and foreland basin formation as either isolated or coupled systems, the in-depth understanding of process linkages and dynamic connectivity between foreland basins and thrust belts, in particular the temporal aspects of thrust deformation and clastic progradation, distinct sediment sources, flexural basin subsidence, thermal history and stratigraphic architecture remain hotly debated. This study aims to develop an unprecedented systematic U-Pb and (U-Th)/He detrital zircon double dating provenance record in the Sevier fold-thrust belt and foreland basin with the objective of spatially and temporally framing the Sevier foreland sedimentary successions in a detailed stratigraphic context as a function of thrust progression and hinterland exhumation. These will be accomplished by means of detailed isotopic provenance information based on crystallization ages and source area thermal history. In addition, data from pre- Mesozoic units exposed in the thrust sheets will be collected to provide a geo- and thermochronometric database that will provide crucial benchmarks for sediment source finger-prints and allow to improve detrital source to sink linkages, better understand larger-scale foreland basin evolution and dynamics, and to refine exhumational lag-time constraints. Our ambitious double-dating campaign in a detailed stratigraphic and structural context will help to (1) elucidate the linkage between thrust deformation (onset and magnitude), hinterland unroofing, and the foreland basin stratigraphic record through improved isotopic provenance analysis, (2) allow for correlation of thrust sheets to proximal and distal basin deposits, and (3) provide novel insights into the dynamic linkage between thrust tectonics, foreland subsidence and sequence stratigraphic architecture in an evolving Sevier foreland basin system in central and east-central Utah. The integration of these data should help improve conceptual models that relate temporal, thermal, and spatial aspects of thrust activity and basin flexural responses to tectonic unroofing, sediment removal and dispersal, and foreland basin sedimentary architecture, and ultimately help differentiate between tectonic, climatic and eustatic forcing factors.