The Tectonic event of the Zaire-Hala’alate thrust belt in Junggar Basin,China

Abstract

Abstract The Yanshanian tectonic activity intensity effect of The Zaire- Hala’alate thrust belt, which is located in the northwest margin of Junggar Basin, have been in dispute for a long time. The distribution characteristics of the FT peak age in the narrower time domain is the key to understanding the dynamic mechanism of this important intracontinental deformation. In this study, apatite fission track dating and thermal history simulation analysis were carried out on 6 samples collected from this area. The results show that the fission track ages are mainly distributed in three intervals, corresponding to the geological ages of 130∼128Ma, 92∼89Ma and 72Ma, reflecting the obvious cooling and uplifting events in the three periods. At the same time, the thermal history simulation shows that the region experienced three rapid uplift events in the Early Cretaceous, the Early Late Cretaceous and the Late Cretaceous-Eocene. The comprehensive study shows that the main thrust fold in this area started from the end of Early Cretaceous, and the tectonic movement was the most intense in Late Cretaceous. As a whole, Tectonic activity migrated from south to north, which shows a retro-thrust expansion from the basin to the orogenic belt.