INTEGRATING IMMEDIATE FAR-FIELD RESPONSE AND PROGRESSIVE NORTHEASTWARD GROWTH OF THE TIBETAN PLATEAU: INSIGHTS FROM CENOZOIC SEDIMENTARY RECORDS IN JIUXI BASIN AT THE NE PLATEAU MARGIN

The Indo-Asian collision has created the >2000 km wide Tibetan Plateau. Opinions towards when the convergence-induced deformation arrived in the NE plateau margin fall into two contrasting models, immediate far-field response or progressive northeastward growth. In this study, we analyzed the Cenozoic strata and recognized a reorganization of sediment dispersal in Jiuxi Basin at ~17 Ma, before and after which the basin received sediments from the north and south source regions, respectively. Independent apatite fission-track analyses in the north source regions (Kuantan Shan-Hei Shan) revealed a rapid exhumation stage during the Paleogene. These results, combined other findings in the northeast Tibetan Plateau, indicate an integrating growth pattern combining an initial stage of immediate far-field response along inherited lithospheric weak zones followed by a later period of progressive northeastward plateau growth.