RUI/Collaborative Research: Plio-Quaternary history of basin evolution, climate change, and fold growth in the Qaidam Basin- investigating wind-enhanced climate-tectonic feedback relationships.

The project aims to document acceleration in fold-growth due to increased wind erosion within the hyperarid western Qaidam Basin, China, and thus would provide the first example of wind-enhanced tectonics on Earth. In addition to understanding climate-tectonic feedbacks, this project will yield multiple high-resolution records of environmental change in the western Qaidam Basin across the late Pliocene climate crash and onset of Northern Hemisphere glaciations. This integrated, basin-scale dataset will provide evidence for desertification rates resulting from this climate shift, and may be useful as an analogue for comparable climate changes observed today. Moreover, the resultant new stratigraphic and structural datasets will be incorporated into a geoscience lab and made freely available via the Science Education Resource Center for educators across the country to use as a teaching tool. The project develops STEM workforce by training of graduate and undergraduate and the international collaboration provides an opportunity for international research experiences for those students. The project is supported by the Tectonics Program (Division of Earth Sciences) and International Science and Engineering (Office of International and Integrative Activities).

Global climate changed to cooler, more arid conditions near the Plio-Pleistocene transition (3.6 to 2.6 Ma), causing environmental changes worldwide. In many regions, concurrent tectonic activity during this time period has evoked hypotheses of climate-tectonic feedbacks, but a causal relationship between observed depositional changes and local tectonics is difficult to quantify. One possible mechanism for climate-enhanced tectonics includes focused erosion across fold crests, or decreased overburden due to lake-level drop, both of which would enhance the isostatic response of uplift. This project, in collaboration with scientists from Lanzhou University (China) and Universite de Rennes (France), will test the hypothesis that climate change (manifested by enhanced aridity in central Asia) at about 3 Ma initiated episodic and spatially non-uniform wind erosion in the western Qaidam Basin in China, which in turn led to an acceleration and enhancement of fold growth. This research focuses on 8 stratigraphic sections spaced evenly throughout the Qaidam Basin and located on the flanks of active anticlines and involves: measurement of detailed sections; magnetostratigraphy; measurements of magnetic susceptibility, O and C stable isotopes; mapping of lithofacies, bed thickness, growth strata, and intraformational unconformities; and construction of 3-D structural models and palinspastic kinematic restorations of the folds. Data from each fold will be synthesized to test hypotheses that lake desiccation resulting from global climate aridification at about 3.0 Ma facilitated wind-erosion that enhanced fold growth on the basin floor; and that the western Qaidam Basin underwent alternating episodes of lake-level lowstands (and wind deflation) and lake-level highstands during Plio-Quaternary glacial and interglacial periods, respectively, in phase with the loess-paleosol successions of the Loess Plateau located to the east. The research project will provide basin-scale data on the relationship between aridification and deformation, allowing a test of whether wind erosion led to accelerated fold-growth.