Abstract In the Yanliao Basin of the North China Craton, the Mesoproterozoic Xiamaling Formation contacted unconformably with the underlying Tieling Formation. This unconformity was caused by the Qinyu Uplift. Underneath this unconformity, the Tieling Formation experienced variably weathering with more extensive erosion of carbonates in the west than in the northeast of the basin. To constrain the timing of the Qinyu Uplift and the duration of subsequent unconformity, cyclostratigraphic analysis was conducted on the Tieling carbonate rocks. Referencing the periodicities of the eccentricity, obliquity and precession obtained from the Mesoproterozoic Xiamaling and Hongshuizhuang Formations, Milankovitch cycles during the Tieling Formation were recognized. A bentonite located at the middle of the Tieling Formation was recognized from the core at the Beizhangzi section, and was considered to be contemporaneous with those found at the Jixian and Liujiagou sections, which had a consistent age of 1441 Ma. Then a deposition rate from the bentonite layer to the top interface of the Tieling Formation was calculated to be 1.65 ± 0.22 cm kyr−1, and the duration time were ca. 9 million years. So the minimum age of the Tieling Formation was ca. 1432 Ma. Combined with our new 207Pb/206Pb weighted average age of 1418 ± 14 Ma obtained from the bottom of the Xiamaling Formation, the Qinyu Uplift was constrained to occur between 1432 Ma and 1418 Ma, older than the previously suggested age of 1400 Ma. The duration of this unconformity was suggested to be no less 14 million years, and might be longer in the western part.

中文翻译：

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利用旋回地层证据界定华北克拉通中元古代秦峪隆起不整合面

摘要 华北克拉通燕辽盆地中元古代下马岭组与下伏铁岭组不整合接触。这种不整合是由秦宇隆起引起的。在该不整合面之下，铁岭组经历了不同程度的风化作用，西部比盆地东北部的碳酸盐岩侵蚀更广泛。为了限制秦峪隆起的时间和随后不整合面的持续时间，对铁岭碳酸盐岩进行了旋回地层分析。参考从中元古代夏马岭组和红水庄组获得的偏心率、倾角和岁差的周期性，识别出铁岭组的米兰科维奇旋回。在北漳子剖面的岩心中发现了位于铁岭组中部的膨润土，认为与蓟县剖面和刘家沟剖面的膨润土是同时期发现的，其年龄一致，为1441 Ma。然后计算出从膨润土层到铁岭组顶部界面的沉积速率为 1.65±0.22 cm kyr-1，持续时间约为 九百万年。所以铁岭组的最小年龄约为。1432 马。结合我们从下马岭组底部获得的新的 207Pb/206Pb 加权平均年龄 1418±14 Ma，秦峪隆起被限制发生在 1432 Ma 和 1418 Ma 之间，比之前建议的年龄 1400 Ma 更老。建议这种不整合的持续时间不少于 1400 万年，