Objective The changes in the material composition of detrital sediments in a sedimentary basin are intimately associated with the uplift and denudation processes of provenance areas. The southern margin of the North China Craton, a primary tectonic unit of the continental area of China, preserves relatively complete geological records of the Permian. The Zhongtiao Mountain area is located in the core of the Fen-Wei graben system on the southern margin of the North China Craton, with the southern margin of the North China Craton and the adjacent Qinling orogenic belt potentially serving as its provenance areas. Therefore, the Zhongtiao Mountain area is an ideal site for exploring the tectonic evolutionary processes of the Qinling orogenic belt and its adjacent areas during the Permian.
Methods This study examined the detrital zircon U-Pb chronology of the coal-bearing rock series of the tidal flat-lagoon facies in the Permian Shanxi Formation and sediments of the alluvial fan-fluvial facies in the overlying Lower Shihezi Formation within the Mitanggou section of the Zhongtiao Mountain area. Then, this study delved into the correlation and tracing of sediment provenance areas. Finally, this study comprehensively explored the coupling between sediment provenance and tectonic processes in the provenance areas.
Results and Conclusions The results indicate that the coal-bearing rock series of the tidal flat-lagoon facies in the Permian Shanxi Formation exhibit nine primary detrital zircon age peaks: 297, 327, 443, 921, 969, 1826, 1990, 2272, 2443 Ma. In contrast, the sediments of the alluvial fan-fluvial facies in the Lower Shihezi Formation manifest five detrital zircon age peaks, namely 305, 1755, 1882, 2284, 2490 Ma, lacking the age records of Neoproterozoic and Eopaleozoic detrital zircons. The analysis reveals that the coal-bearing rock series originate primarily from the North Qinling orogenic belt and the southern margin of the North China Craton. In comparison, the sediments of the alluvial fan-fluvial facies are merely derived from the southern margin of the North China Craton. The differences in sediment provenance respond to the interactions between the North China Plate and the Qinling-Dabie plate during the Early-Middle Permian, suggesting that tectonic activity gradually migrated from south to north. In the early and middle stages of the Early Permian, the overall low uplift of the southern margin of the North China Craton allowed the sediments from the North Qinling orogenic belt to enter the Zhongtiao Mountain area. From the late stage of the Early Permian to the early stage of the Middle Permian, the rapid and significant uplift of the southern margin of the North China Craton blocked the sediments from the North Qinling orogenic belt. As a result, the Zhongtiao Mountain area failed to receive sediment supply from the North Qinling orogenic belt. This study provides new sedimentological evidence for the Permian tectonic processes of the southern margin of the North China Craton and the adjacent Qinling orogenic belt.
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