Rheology of the lithosphere beneath the central and western Tien Shan

Research on the Western Tien-Shan reveals that the lithosphere beneath this region exhibits remarkable insensitivity to lateral temperature variations, with strength variations limited to a factor of 2 to 4 despite significant temperature differences. This suggests that the strength-controlling portion of the lithosphere is not strongly dependent on temperature, contrasting with expectations for high-temperature creep mechanisms. The study utilized crustal velocity data and seismic tomography to model strain rates and gravitational potential energy variations, estimating an effective viscosity lower bound of approximately 10^22 Pa s. Plastic deformation of dry, pyroxene-rich lower crust may also contribute to this temperature-insensitive strength profile.

England, P., & Molnar, P. (2015). Rheology of the lithosphere beneath the central and western Tien Shan. Journal of Geophysical Research: Solid Earth, 120(5), 3803–3823. Portico. https://doi.org/10.1002/2014jb011733