[Objective and Methods]Triassic strata are considered absent in the Yungang Basin in northcentral North China,while the Shihezi Formation at the top of the Yangquantou section within the Yungang Basin belongs to the Lower Triassic Liujiagou Formation based on the regional geological survey results of the 1:50000 Shijiatun map. To settle the dispute and determine the reliability of this new understanding,this study conducted lithostratigraphic correlation and detrital zircon dating of the Shihezi Formation from the Madaotou and Yangquantou sections within the Yungang Basin,and compared with other contemporaneous stratigraphic sections in northcentral North China to de-termine its deposition age.[Results and Conclusions]It shows that the 'so-called' Liujiagou Formation identified in the upper part of Yangquantou section has similar lithofacies associations and gravel compositions with the Shihezi Formation in the Madaotou section,and they are both characterized by grey-green or yellow-green medium-to thick-bedded medium-to coarse-grained sandstone interbedded with thin-bedded purple-red siltstone and sandy mudstone,as well as several layers of thick conglomerates. This differs from the diagnostic characteristics of the Liujiagou Forma-tion in the Fugu,Ningwu,Taiyuan Xishan,and Qinshui Basins in North China,which are characterized by abun-dant light to fresh red thick-bedded medium-to fine-grained arkose. Moreover,the youngest detrital zircons ages (288.0±4.7 Ma) constrained the maximum depositional age to the Middle Permian. Therefore,the strata at the top of the Yangquantou section belongs to the Middle Permian Shihezi Formation,not the Liujiagou Formation. It is inferred that the orogenic belts in the northern margin of North China likely experienced intense compression and uplift during the Late Triassic,resulting in the denudation of the Triassic strata within the Yungang Basin,which was then uncon-formable overlain by the Lower Jurassic strata.
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