The Devonian Maoniushan Formation of the northern Qaidam basin is characterized by alluvial fan coarse- grained sediments and intermediate- acid volcanic rocks, recording core rocks exhumation process of the North Qaidam tectonic belt from collisional to post orogenesis. LA- ICP- MS U- Pb weighted mean ages of the upper and lower Maoniushan Formation tuff deposited around the Gahainanshan Mountain are 396. 6±2. 4 Ma (MSWD=0. 39, n=14) and 396. 9±2. 5 Ma (MSWD=0. 052, n=14), respectively, indicating the depositional time of the Maoniushan Formation is almost late Early Devonian. Different detrital zircons collected from different outcrops are characterized by diverse LA- ICP- MS U- Pb populations, that is, sample 20QH- 19 collected from the field investigation A, which is located in the Gahainanshan Mountain, is characterized by multiple- peak ages dated at about 532~505 Ma, 935~891 Ma, 1136~1064 Ma and 3110~1309 Ma; sample 20QH- 21 collected from the field investigation B, which is located in the Gahainanshan Mountain, is characterized by multiple- peak ages dated at about 537~443 Ma, 1073~798 Ma and 2463~1785 Ma, and sample 20QH- 22 is featured by a predominantly unique peak age dated at ~420 Ma, whose pattern is similar to the sample 20QH- 26 collected from the field investigation C. Diverse U- Pb age populations indicate that the detrital materials of the Maoniushan Formation were mainly sourced from the Silurian- Devonian syn- orogenesis igneous rock, the Cambrian- Ordovician Tanjianshan Group, the Shaliuhe Group of the North Qaidam tectonic belt and the Olongbuluke terrane. Rock assemblage characteristics, developments of depositional systems, U- Pb ages of tuff rocks and sediment dispersal patterns of the Maoniushan Formation indicate that autochthonous sedimentation, rapid deposition, scattered and disconnected sedimentary environments. Provenance analysis of the Maoniushan Formation sediments indicate that the source areas had undergone rapid exhumation process and probably evolved into the extensional collapse stage followed the post- orogenesis during the deposition of the Maoniushan Formation.