Late Cretaceous-Cenozoic Exhumation of Northwestern Guangxi (China) and Tectonic Implications: Evidence from Apatite Fission Track Dating

Abstract The study of the Late Cretaceous-Cenozoic uplift and tectonic evolution of the Northwestern Guangxi area in the Youjiang Basin is relevant for understanding the origin and preservation of hydrothermal deposits with ore-hosting potential. Apatite fission-track dating and time-temperature thermal history modelling were performed using six rock samples from the study area. The ages were found to range from 14 to 81 Ma, and in particular, three distinct time intervals could be defined using the apatite fission-track ages: 81–77 Ma, 58–35 Ma, and 17–14 Ma, each corresponding to a specific tectonic-thermal event. The 81–77 Ma event indicates the age of early magmatic activity in northwestern Guangxi. The earliest Himalayan tectonic phase could be attributed to the subduction–collision of the Indo-Asian plate at 58–35 Ma, followed by a second phase of rapid wedging of the Indian plate during the 17–14 Ma interval. We surmise that some hydrothermal deposits, including medium-temperature Cu, Pb, Zn deposits and high-temperature W, Sn, Mo, Bi deposits such as polymetallic Cu–Fe–Mo, and Cu–Mo–(Pb–Zn) porphyry types and skarn types, may be locally present below the low-temperature Carlin-type gold deposits, or at variable depths in northwestern Guangxi. And sand gold deposits may be a relevant prospecting target.