物源分析是判断古侵蚀区位置和恢复盆山格局特征的重要方法之一.应用古流向、砾石组分、砂岩组分和碎屑锆石年龄研究,分析北祁连—北山地区下白垩统的物源,进一步探讨早白垩世盆山格局.综合研究认为,早白垩世北祁连-北山地区的沉积物源分别来自南、北两大物源区.南部物源区由奥陶纪北祁连洋火山孤、中-晚志留世—泥盆系中祁连与阿拉善地块碰撞造山花岗岩、新元古代中祁连裂解岩浆岩与变质岩基底、早中生代南祁连岩浆岩组成；北部物源区则主要为华北克拉通西北缘古生代—中生代早期增生造山与后碰撞期花岗岩、塔里木板块东部敦煌-库鲁克塔格地块古元古代岩浆岩和深成变质岩.早白垩世初期,走廊带的沉积物源主要来自北部物源区,早白垩世早期南、北部物源同时存在,早白垩世中期则逐渐以南部源区为主,早白垩世晚期西北部和南部同时为物源供给区.整个早白垩世期间,北祁连-北山东部为统一的内陆湖盆群.%Provenance analysis is an effective and important approach to tracing the origin of sedimentary basin fills and reconstructing the orogenic history of basin-bounding uplifts. In this paper, the authors used palaeocurrents, gravel components, detrital compositions and U-Pb ages of detrital zircons to systematically analyze the provenance of the Lower Cretaceous basin in the North Qilian Moun-tain-Beishan area and, furthermore, discussed the basin-mountain framework in the Early Cretaceous period. In Beishan area, the On such a basis, two provenances were identified. The south provenances were composed of metamorphic basement and Neoproterozoic magmatic rocks from the Central Qilian Terrance, the North Qilian Volcanic Arc (O), magmatic rocks originated from the collision (S2-3-D) and the Early Mesozoic igneous rocks in the South Qilian Mountain. However, the north provenances were composed of Pa-leoproterozoic magmatic rocks and deep metamorphic rocks from the Dunhuang-Kuruktag terrance, located in the northeast of Tarim Block, and the granites were produced by the collision and post-collision in the northwest of North China in Paleozoic-Early Mesozoic period. Besides, the evolution of the source suggests that the north source provided sediments for the Corridor in the initial period, and then both provenances existed in the early period. In the middle stage, the south provenance became the main source, while the northwest and south sources supplied sediments together finally. In a word, the eastern North Qilian Mountain-Beishan area seems to be a unified interior basin.
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