The northern Alxa orogenic belt, located in the middle segment of the Central Asian Orogenic Belt, is a junction between the North China Craton, Tarim Craton and Mongolian microcontinents. However, its Permo-Carboniferous tectono-palaeogeographic evolution has not been well established. In this study, new zircon U–Pb–Hf isotopic data for the Permo-Carboniferous clastic rocks were used to address the above issue. Based on our dating work and fossil assemblages, we confirmed that the Amushan, Maihanhada, Aqide and Haersuhai formations were formed in the late Carboniferous to early Permian, early to middle Permian, middle Permian and late Permian periods, respectively. The Amushan Formation sandstone in the Zhusileng area contains abundant Palaeozoic zircons (with age peaks at 440 Ma, 475 Ma and 539 Ma) and some Precambrian zircons. These zircon ages and the southeast transgressive direction suggest the provenance to be the local Zhusileng–Hangwula block and the nearby Yagan continental margin. The zircon age pattern with a high proportion of detrital zircons much older than the depositional time and no detrital zircons close to the depositional time suggest an extensional basin depositional setting. The clastic rocks of the Maihanhada, Aqide and Haersuhai formations inherited the source for the Amushan Formation, with a greatly increased input of Permo-Carboniferous volcanic rocks with post-collision or intraplate chemical affinity. Accordingly, a Permo-Carboniferous extensional stage was suggested. Finally, a tectono-palaeogeographic model was reconstructed for the northern Alxa orogenic belt, evolving from a late Carboniferous transgression with crustal extension to early to middle Permian rapid basin filling and a late Permian marine regression.

中文翻译：

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阿拉善北部二叠纪-石炭纪沉积物碎屑锆石U-Pb-Hf同位素：中亚造山带中段物源及构造意义

阿拉善北部造山带位于中亚造山带中段，是华北克拉通、塔里木克拉通和蒙古微大陆的交界处。然而，其二叠纪-石炭纪构造-古地理演化尚未得到很好的证实。在这项研究中，新的锆石 U-Pb-Hf 同位素数据用于二叠纪-石炭纪碎屑岩，用于解决上述问题。根据我们的年代学工作和化石组合，我们确认阿木山组、麦罕哈达组、阿奇德组和哈尔苏海组分别形成于石炭纪晚期至二叠世早期、二叠世早期至中二叠世、中二叠世和二叠纪晚期。朱思棱地区阿木山组砂岩中含有丰富的古生代锆石（年龄峰在440 Ma、475 Ma和539 Ma）和一些前寒武纪锆石。这些锆石年龄和东南海侵方向表明其物源是当地的朱斯棱-杭乌拉地块和附近的雅干大陆边缘。具有高比例碎屑锆石的锆石年龄模式远早于沉积时间，并且没有接近沉积时间的碎屑锆石，表明伸展盆地沉积环境。麦罕哈达组、阿奇德组和哈尔苏海组碎屑岩继承了阿木山组的物源，具有碰撞后或板内化学亲和力的二叠系-石炭系火山岩的输入量大大增加。因此，提出了二叠纪-石炭纪伸展阶段。最后，重建了阿拉善北部造山带的构造古地理模型，