Beishan thermochronology 2022

We report apatite (U-Th)/He thermochronology from the Beishan fold-thrust belt, central Asia. Based on these data, we interpret ~140-133 Ma cooling in the Early Cretaceous to reflect hanging wall exhumation during thrust slip along the Hongqishan thrust in the Hongliudaquan area, southeastern Beishan. And we infer that the normal slip of the Suosuojing fault was responsible for footwall exhumation at ~124‒115 Ma in the Early Cretaceous. The late Mesozoic development of the Beishan fold-thrust belt in central Asia should be a far-field response to the closure of the Mongol‒Okhostk Ocean in the north and the Lhasa‒Qiangtang collision in the south, followed by collapse of thickened crust that triggered the post-thrusting extensional deformation.我们报道了中亚北山褶皱冲断带（Beishan fold-thrust belt）的磷灰石（U-Th）/He热年代学数据。基于该批数据，我们将早白垩世（Early Cretaceous）约140~133 Ma的冷却事件，解释为北山东南部红柳大泉地区红石山逆冲断裂（Hongqishan thrust）发生冲断滑移时，上盘遭受剥露的反映。同时我们推断，索索井断裂（Suosuojing fault）的正滑作用，是早白垩世约124~115 Ma下盘剥露的成因。中亚北山褶皱冲断带的晚中生代演化，应是北部蒙古-鄂霍次克洋（Mongol‒Okhostk Ocean）闭合、南部拉萨-羌塘碰撞（Lhasa‒Qiangtang collision）所引发的远场响应；随后加厚地壳（thickened crust）的垮塌，触发了逆冲后的伸展变形（post-thrusting extensional deformation）。