Constraining the crustal structure under the central and western Tian Shan based on teleseismic receiver functions and gravity anomalies

A study of the Tian Shan, a vast Asian mountain range, reveals significant lateral variations in crustal thickness and the ratio of P- to S-wave velocities (vP/vS), providing insights into its tectonic evolution. Researchers used a novel H-stacking method combining teleseismic receiver functions and gravity anomalies to analyze 91 seismic stations across the central and western Tian Shan. Findings indicate a ∼45-km-thick crust with intermediate-high vP/vS ratios in the Kazakh Shield and Tarim Basin, suggesting a mafic crystalline basement and lower crust. The central Tian Shan exhibits variable crustal thickness (40–64 km) and vP/vS ratios (1.65–2.00), potentially due to crustal shortening, mafic underplating, and melting, while the western Tian Shan shows a thinner crust (42–50 km) with intermediate vP/vS ratios (~1.78). These differences imply that the Talas-Fergana Fault may extend through the lithosphere.

Li, Y., Tang, H., & Shi, L. (2023). Constraining the crustal structure under the central and western Tian Shan based on teleseismic receiver functions and gravity anomalies. Earthquake Science, 36(1), 1–14. https://doi.org/10.1016/j.eqs.2023.02.005