Seismically Triggered Soft-Sediment Deformation Structures In Tashkorgan Lacustrine Sediments, Northeastern Pamir, China

Soft-sediment deformation structures (SSDSs) are widely developed in the lacustrine sediments of paleo-dammed lakes in tectonically active regions and contain a wealth of information on regional fault activity. In this study, multiple SSDSs (load structures, small-scale slump structures, droplets, diapir and pillow structures, silty-clay pillars and large-scale slump structures) were identified in the strata of the Late Pleistocene lacustrine sedi-ments in the Tashkorgan River drainage in northeaster n Pamir. The deformation mechanisms of the SSDSs were related to the liquefaction, fluidization and thixotropic behaviors. The regional tectonic settings and SSDS fea-tures point toward a trigger mechanism with seismic activities and indicate that the seismogenic faults were possibly related to the southern part of the Kongur Shan extensional system. Accelerator mass spectrometr y (AMS) radiocarbon dating data showed that the SSDSs in the Tashkorgan lacustrine sediments formed 30,221-29,932 cal BP and 25,825-25,317 cal BP. The results of this study improve ou r understanding of fault activity and geodynamic processes in northeaster n Pamir during the Late Pleistocene.