Mesozoic-Cenozoic tectonic uplift events of Xiangshan Mountain in northern North-South Tectonic Belt, China

The North-South Tectonic Belt is located in the conjunction region among the Ordos Block, the Alxa Terrane, the Qin-Qi Orogenic Belt and the Xing-Meng Orogenic Belt, which has a special tectonic location and complex evolutionary history. This paper is designed to take the Xiangshan Mountain located in the north segment of the North-South Tectonic Belt as the study area for discussing its Mesozoic-Cenozoic uplifting history. Apatite and zircon fission track dating and time-temperature thermal history modeling are carried to analyze on nine samples in the Xiangshan Mountain. The results indicate that the Xiangshan Mountain underwent four cooling events which occurred in Late Triassic-Early Jurassic, Late Jurassic-Early Cretaceous, Late Cretaceous and Eocene, respectively. The four cooling events have a good response to the regional background and field geology. In addition, the thermal history modeling indicates that the uplifting process of the Xiangshan Mountain can be divided into two stages of rapid uplifting events since the Late Cretaceous, one occurred in the Eocene was the response of the Ningnan area to the Cenozoic peripheral rifting and breakup event of the Ordos Block. It is worth noting that the analysis results do not reflect the rapid uplift of the study area at about 8Ma, indicating the uplift of the Tibet Plateau had a limited impact on the Xiangshan area.