Tectonic geomorphology and numerical surface-process modeling in the Pamir

• Applicant: Professor Dr. Richard Gloaguen
• Subject Area: Palaeontology
• Term: from 2009 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 140678784

We aim to establish the Late Cenozoic deformation field of the Pamir by localizing and characterizing active and neotectonic deformation structures, and setting up the drainage-basin, river-capture, river-reversal, and regional erosion history. Our hypothesis is that the neotectonics is governed by subduction beneath the frontal part of the orocline, E–W extension in the intra-plateau Karakul-lake rift, and transtension (east) and transpression (west) along the lateral margins of the orocline, a result of oroclinal formation, rotation of the Indian indenter, and focused precipitation caused by the Westerlies. The model for the evolution of the drainage system involves: growth of the Pamir by N-ward propagating deformation, establishing E-trending belts of shortening and rivers/drainages; diversion and blocking of these rivers by the development of the lateral boundaries of the orocline that resulted in river capture and reversal. Even the present-day Panj (Amu Darya) is affected by ongoing uplift: tilted river terraces, wind gaps, and abnormal intersection of streams of different order indicate that large parts of the river have changed flow direction. The determination of a number of geomorphic indices with remote sensing techniques will identify areas experiencing tectonic deformation. Locally, we will quantify the deformation by leveling and dating of river terraces. Regionally, we will determine bedrock uplift and erosion by remote sensing and low- temperature geochronology. Our hypotheses will be tested by means of 3D numerical modeling of landscape evolution coupled with lithospheric-scale thermomechanical models of the Pamir–Tien Shan orogen. For that we are developing a new, highly efficient numerical model for surface processes that is able to simulate precipitation, erosion, and mass transport on high-resolution DEMs. Results of the field studies will be used to calibrate model parameters and to constrain modeling results.

• DFG Programme: Research Grants
• Participating Persons: Dr. Matthias Krbetschek (†); Professor Dr. Lothar Ratschbacher