Tectono-thermal evolution of the northern Tarim Basin, Central Asia: New insights from apatite low-temperature thermochronometers

Abstract

The research on the tectono-thermal histories of the northern Tarim Basin, particularly the eastern Kuqa fold-and-thrust belt (KFTB) is crucial for comprehending the basin-mountain tectonic evolution and related coupling in the central Asia. This study aims to reconstruct the tectono-thermal history of the eastern KFTB with a combination of apatite fission track (AFT) ages, apatite (U-Th)/He (AHe) ages and vitrinite reflectance data. The central AFT ages of the samples range from 22.93 Ma to 156.59 Ma, which are younger than the corresponding stratigraphic ages. The single-grain AHe ages range from 4.23 Ma to 24.92 Ma and display some dispersion, likely due to radiation damage and/or grain size effects. Thermal modeling results indicate that the eastern KFTB mainly experienced the Cretaceous and Miocene rapid cooling events (althouth the timing and magnitude of these events varied among the samples), which were related to the collisions of the Qiangtang-Lhasa Terranes and India Plate with the southern margin of the Eurasia Plate. The paleo-heat flow of the eastern KFTB decreased from the Late Triassic (54 ∼ 55 mW/m2) to the Early Miocene (44 ∼ 47 mW/m2) and then increased since the Late Miocene due to thrust fault activity. Furthermore, we reappraised the maturation evolution histories of the source rock in the Huangshanjie and Yangxia formations using the new thermal hirtories, which were consistent with the hydrocarbon charging and accumulation time, as indicated by the homogenization temperature of fluid inclusions. Overall, this study provides valuable insights into the tectono-thermal histories of the eastern KFTB. It enhances our understanding of the tectonic evolution of Central Asia and holds great significance for further hydrocarbon exploration and development in the northern Tarim Basin.