Uplift of the west Kunlun Range, northern Tibetan Plateau, dominated by brittle thickening of the upper crust

• Published in: Geology (Boulder) 2013-04, Vol.41 (4), p.439-442
• Main Authors: Jiang Xiaodian, Jiang Xiaodian, Li, Zheng-Xiang, Li Haibing, Li Haibing
• Format: Article
• Language: English
• Subjects: applied (geophysical surveys & methods); Asia; Bouguer anomalies; brittle deformation; China; Correlation analysis; crust; crustal shortening; crustal thickening; deformation; Far East; faults; Geology; Geomorphology; geophysical methods; geophysical profiles; geophysical surveys; Geophysics; gravity anomalies; Kunlun Mountains; mechanism; Mohorovicic discontinuity; northern Tibetan Plateau; seismic methods; seismic profiles; Seismology; Structural geology; surveys; Tibetan Plateau; Topography; uplifts; upper crust; vertical seismic profiles; western Kunlun Mountains
• ISSN: 0091-7613; 1943-2682
• DOI: 10.1130/G33890.1

High-resolution seismic reflection data from the West Kunlun Range front show that crustal structures beneath the northwestern margin of the Tibetan Plateau are dominated by nappes of upper crustal rocks. Geological cross-section balancing suggests an average of 24.6-54 km (38%-52%) of upper crustal shortening. This horizontal shortening by brittle folding and faulting in the upper crust correlates positively with crustal thickening, an increase in Moho depth by 5-7 km, and the topography. Our work suggests that upper crustal shortening is a chief factor for topographic uplift and crustal thickening at the northwestern margin of the Tibetan Plateau. Such a mechanism is different from that proposed for the plateau south of the Karakax strike-slip fault, where crustal flow may have played a prominent role in plateau uplift.