Holocene left-slip rate determined by cosmogenic surface dating on the Xidatan segment of the Kunlun fault (Qinghai, China)

Cosmogenic dating, using in situ {sup 26}Al and {sup 10}Be in quartz pebbles from alluvial terrace surfaces, constrains the late Holocene slip rate on the Xidatan segment of the Kunlun fault in northeastern Tibet. Two terrace risers offset by 24 {+-} 3 and 33 {+-} 4 m, having respective ages of 1799 {+-} 388 and 2914 {+-} 471 yr, imply a slip rate of 12.1 {+-} 2.6 mm/yr. The full range of ages obtained ({le}22.8 k.y., most of them between 6.7 and 1.4 k.y.) confirm that terrace deposition and incision, hence landform evolution, are modulated by post-glacial climate change. Coupled with minimum offsets of 9--12 m, this slip rate implies that great earthquakes (M {approximately}8) with a recurrence time of 800--1000 yr, rupture the Kunlun fault near 94 E.

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