Warm versus cold crust in the Tien Shan orogenic belt revealed by seismic Lg attenuation tomography

Seismic Lg-wave attenuation tomography reveals distinct thermal structures within the Tien Shan orogenic belt, highlighting a 'warm versus cold crust' dichotomy. The central Tien Shan exhibits prominent low-QLg anomalies, indicating hot mantle upwelling and associated surface uplift driven by lithospheric compression. In contrast, the eastern and western regions show high-QLg values, suggesting colder, more stable crustal conditions. Notably, a low-Q anomaly at the Pamir Plateau-western Tien Shan junction points to thermal subduction-induced processes tied to the India-Eurasia collision. The Kazakh Shield's high-QLg values imply it acts as a cold, rigid barrier, mitigating far-field tectonic effects. This study leverages high-resolution Lg-wave attenuation modeling (0.05–10.0 Hz) to infer crustal thermal variations, offering insights into the dynamic interplay of compression and mantle upwelling in shaping the region's topography.

Ma, X., Zhao, L.-F., Xie, X.-B., Chang, X., & Yao, Z.-X. (2023). Warm versus cold crust in the Tien Shan orogenic belt revealed by seismic Lg attenuation tomography. Geophysical Journal International, 233(3), 2142–2154. https://doi.org/10.1093/gji/ggad055