Chuansong He

Seismic Evidence for a Geosuture between the Yangtze and Cathaysia Blocks, South China

South China, composed of the Yangtze and Cathaysia Blocks and the intervening Jiangnan orogenic belt, has been central to the debate on the tectonic evolution of East Asia. Here we investigate the crustal structure and composition of South China from seismic data employing the H-k stacking technique. Our results show that the composition and seismic structure of the crust in the Jiangnan orogenic belt are identical to those of the Cathaysia Block. Our data reveal a distinct contrast in the crustal structure and composition between the two flanks of the Jiujiang-Shitai buried fault. We propose that the Jiujiang-Shitai buried fault defines a geosuture between the Yangtze and Cathaysia Blocks, and that the felsic lower crust of the Cathaysia Block and the Jiangnan orogenic belt may represent fragments derived from the Gondwana supercontinent.

Continental dynamics in a multi-convergent regime: a receiver function study from the North–South-Trending Tectonic Zone of China

The North–South-Trending Tectonic Zone (NSTZ) marking the transition between West China and the North China Craton is an earthquake-prone region. The NSTZ is located along the junction between the Indian Plate–Tibetan Plateau collision and E–W extrusion, as well as the westward subduction of the Pacific Plate, thus constituting an important region for studies related to continental dynamics. Here, we investigate the structure of the crust and upper mantle along this zone by employing the H-k stacking of receiver function and the depth domain receiver function. Our results identify notable variation in crustal thickness, an elevation of the upper mantle discontinuities, and convective removal of the mafic lower crust through either delamination or Pacific Plate subduction beneath the region, generating a cold domain in the mantle transition zone. The converging tectonic stresses contribute to making the NSTZ an earthquake-prone zone.