The predominantly calcareous Taiyuan Formation was formed during the Late Paleozoic period in the southern part of the North China block in the eastern Palaeotethys. We present the rare earth elements (REE) and petrography data from nine limestone beds in the Zhangji mine of the Huainan coalfield as proxies to interpret the depositional environment of Taiyuan Formation. Thin-section petrography indicates that the limestones are mainly bioclastic, in-situ and are characterized by matrix-supported cementation. The REE concentrations and elemental patterns in the limestones reflect deposition in a normal marine environment. The REE analyses show the depletion of light rare earth elements, positive La anomalies, and negative Gd anomalies. Moderately negative δCe anomalies indicate that the limestones are most likely formed in an oxidized setting, typically a shallow marine environment. The positive Eu anomaly suggests deposition in a coastal environment with influx of clastics and terrestrial organic matter, thus indicating a more southerly provenance. Results from this study highlight the utility of REE and trace-element analyses of carbonate rocks for the reconstruction of depositional environments.

中文翻译：

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稀土元素解释的华北地块太原组灰岩沉积环境

以钙质为主的太原组形成于晚古生代，位于古特提斯东部华北地块南部。我们提供了淮南煤田张集矿 9 个石灰岩层的稀土元素 (REE) 和岩石学数据，作为解释太原组沉积环境的代理。薄片岩相学表明，石灰岩主要是原位生物碎屑岩，以基质支持胶结为特征。石灰岩中的稀土元素浓度和元素模式反映了正常海洋环境中的沉积。REE 分析显示轻稀土元素耗尽、La 正异常和 Gd 负异常。中度负的 δCe 异常表明石灰岩最有可能在氧化环境中形成，通常是浅海海洋环境。正的 Eu 异常表明沉积在沿海环境中，碎屑和陆地有机物流入，因此表明更靠南的来源。这项研究的结果突出了碳酸盐岩的稀土元素和微量元素分析在沉积环境重建中的实用性。