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This dissertation investigates the structural geology and tectonic evolution of the eastern Tibetan Plateau, a region shaped by the far-field effects of the Cenozoic India–Asia collision. Despite its importance for understanding collisional tectonics, the mechanisms of crustal deformation driving its uplift remain poorly understood. A fundamental issue is the lack of surface constraints due to limited systematic geologic field mapping in this region—a problem highlighted by recent large-magnitude earthquakes rupturing previously unmapped faults. To address this gap, new geologic mapping conducted over a ~30,000 km2 region is integrated with seismic reflection profile interpretations to construct balanced cross-sections, tectonic models, and maps that quantify and constrain deformation in the Longmen Shan, Min Shan, and surrounding Songpan-Ganzi terrane. Specific findings include: (1) systematic along-strike variations in the style, timing, and magnitude of shortening in the Longmen Shan; (2) a previously unrecognized crustal-scale tectonic wedge beneath the Min Shan; and (3) a regionally distributed conjugate strike-slip fault system across eastern Tibet. These findings are synthesized into a three-dimensional tectonic framework that encompasses active crustal deformation, surface uplift, and basin development.
The results of this study resolve several long-standing enigmas of the region, including high topography despite unusually slow geodetic slip rates, restricted Cenozoic foreland basin development along the plateau margin, and the inability of range-bounding faults to account for uplift of the Min Shan. The details of crustal deformation outlined in these models contribute to the debate of ductile channel flow versus brittle thrusting for the development of the eastern plateau, where results align most closely with a modified version of the thrust model that features wedge and duplex structure development. The pre-Cenozoic shortening and along-strike structural transitions highlighted by this study are additional features not captured by the previously proposed endmember models. Another contribution of this work is the synthesis of new and previously mapped active faults across this region, which are significant due to the numerous large earthquakes that have occurred along previously unmapped faults in this region, thus improving understanding of seismic hazards. More broadly, this work advances understanding of mechanisms of continental deformation and orogenic plateau growth in collisional settings.