| Determining the temporal and spatial relationships amongst topography of mountain belts, tectonics, and climate change is an important, yet poorly understood, problem in the earth sciences. The research presented here applies stable isotope based paleotopographic methods to unresolved questions regarding the links and feedbacks between topography, tectonics, and climate in the Great Basin region. In the northern Great Basin, the terrestrial authigenic mineral stable isotopic records produced suggest the region experienced ∼2km of surface uplift during the Eocene, and ∼1.5km of surface subsidence since the middle Miocene. In the southern Great Basin, the authigenic mineral stable isotope records produced suggest the region experienced ∼1--2km of surface subsidence since the early Miocene. In contrast, a pre-extensional surface uplift event is interpreted from the authigenic mineral isotopic record from the Lake Mead area. This pattern of north to south surface uplift and subsidence is similar to the timing of magmatism in the Great Basin region. These spatial patterns reinforce tectonic models for the western United States that link mantle-derived magmatism to surface uplift, such as convective removal of lower lithosphere after Laramide tectonic thickening or post-Laramide removal of the subducting Farallon slab. The terrestrial isotopic records presented here capture the Tertiary topographic evolution of the Great Basin, and allow links to be recognized between topographic evolution and significant tectonic events in the region. |
