Cenozoic exhumation in the Tianshan is controlled by a complex interaction between tectonics and climate. However, the timing and magnitude of exhumation of the Tianshan and its contribution to climate change in Central Asia remains debated. In this study, we report new apatite fission track and (U‐Th)/He ages for granite samples from the roof of the South Tianshan that are significantly younger than those published for other parts of the South Tianshan. Inverse and forward modeling reveals two phases of accelerated cooling at 10∼6 Ma and since ∼3 Ma, which can be linked to (1) the reactivation of strike‐slip faults and hot asthenospheric upwelling during India‐Eurasia convergence and (2) the interplay between tectonics and glaciation, respectively. The 10∼6 Ma exhumation phase further corresponds to the timing of climate change, suggesting that this exhumation phase significantly contributed to the enhanced aridification of the Tarim Basin.

The Tarim Basin, which is the largest basin in Central Asia, experienced a complicated tectonic evolution along with the development of the South Tianshan, Kunlun Mountains, and the Tibetan Plateau during the Phanerozoic. This article provides a systematic overview of the thermal regime of the Tarim Basin based on new results and previous studies. The present-day average heat flow and geothermal gradient of the Tarim Basin are 42.5 ± 7.7 mW/m2 and 20.7 ± 2.9°C/km, respectively. The palaeo-geothermal gradient in the eastern and central parts of the Tarim Basin during the early Palaeozoic was 35–39°C/km, which is higher than the gradient of 28–34°C/km in the northwestern part of the Basin. The palaeo-geothermal gradient has decreased gradually since the late Palaeozoic. Except for the Southeast Uplift, the thickness of the thermal lithosphere in most of the Tarim Basin ranges from 164 km to 205 km, and the Moho temperature varies from 520°C to 614°C. The thermo-rheological structure of the lithosphere in the Tarim Basin can be approximated by a typical jelly sandwich model with the exception of the Southeast Uplift, which can be represented by a crème brûlée model. Generally, the long-term sedimentation and subduction of the adjacent mountains had an important effect on the spatial differentiation of the thermal regime in the Tarim Basin. This study provides a detailed description of the shallow and deep thermal states of the Tarim Basin, which are important for hydrocarbon exploration in the basin and structural research on Central Asia.

The Fukang Sag in the Junggar Basin is an important petroleum exploration and exploitation region. However, the geothermal regime and tectono-thermal evolution of the Fukang Sag, which control its hydrocarbon generation and conservation, are still controversial. This study involved a systematic analysis of the present-day geothermal gradient, heat flow, and thermal history of the Fukang Sag for better further exploration. According to the well log data and well-testing temperature data, we calculated that the geothermal gradient of the Fukang Sag ranges from 16.6 °C/km to 29.6 °C/km, with an average of 20.8 °C/km, and the heat flow ranges from 34.6 mWm⁻² to 64.3 mWm⁻², with an average of 44.6 mWm⁻². Due to the basement relief, they decrease from northeast to southwest. The weight averages of the single-grain apatite (U-Th)/He ages of the core samples are 1.3–85.2 Ma, and their apatite fission track ages range from 50.9 Ma to 193.8 Ma. The thermal modeling results revealed that the Fukang Sag experienced late Permian, late Jurassic, and late Cretaceous cooling events (although the timing and magnitude of these events varied among the samples), which were related to the continuous compression of the Junggar Basin. In addition, basin modeling indicated that the heat flow of the Fukang Sag decreased from 80 mWm⁻² in the Carboniferous to the current value of 44.6 mWm⁻². The Fukang Sag’s edge exhibits prolific hydrocarbon generation in the Carboniferous–Permian source rocks, while the Jurassic source rocks within the sag also undergo abundant hydrocarbon generation. This study provides new insights into the present-day geothermal field and tectono-thermal evolutionary history of the Fukang Sag, which are significant in terms of regional tectonic evolution and oil and gas resource assessment.