Integrated stratigraphic, geomorphic, sedimentologic, numeric, and experimental study of hangingwall ramp architecture in continental half grabens

University Of New Mexico, Albuquerque NM

Investigators

Abstract

Integrated stratigraphic, geomorphic, sedimentologic, numeric, and experimental study of hangingwall ramp architecture in continental half grabens. By Gary A. Smith and John W. Geissman EAR-0344146 This project integrates geomorphic and sedimentologic field studies with experimental and computational approaches to elucidate tectonic and climatic controls on the development of stratigraphic sequences within differentially subsiding and tilting, nonmarine extensional basins. The research is motivated by the hypothesis that differential subsidence across the hangingwall ramp, or sediment flux from large drainage basins on the hangingwall ramp, or both, controls the accumulation, stratigraphic architecture, sediment preservation, and caliber of sediment throughout much of the basin, as well as the development of unconformities and sedimentary bypass surfaces. Numerical simulations predicting specific facies patterns will be tested using experimental methods and field data collected in a well-mapped, well-dated extensional basin in the Rio Grande rift of New Mexico. New magnetostratigraphic data will enhance the chronological database required for the project. PIs research approach differs from traditional stratigraphic methods primarily through integration of geomorphic and stratigraphic methods for modeling aggrading continental successions to predict patterns of sediment dispersal in half graben settings. The resulting insights into the origin of basin-fill architecture will have immediate implications for conceptualizing aquifer structure in the arid western United States.