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采集了皖北新元古代沟后组和寒武纪猴家山组石灰岩,进行系统的岩石学和稀土地球化学分析,研究了灰岩中稀土的来源及其特征,并据此对灰岩形成的海水稀土配分模式进行反演,探讨了皖北新元古代-寒武纪大地构造背景。结果表明:沟后组石灰岩稀土元素总量较高(10.66～30.68 ppm),轻重稀土分异明显,轻稀土富集,NdSN/YbSN在1.12～1.46之间,受陆源碎屑混染影响严重;猴家山组石灰岩稀土总量偏低(1.63～7.79 ppm),轻重稀土分异微弱,轻稀土略亏损,LaSN/NdSN在0.35～1.28,受陆源影响较小;石灰岩样品均具有程度不同的La正异常、Ce负异常和Y正异常;猴家山组灰岩反演海水稀土特征与新元古代海水略有差异,与现代海水稀土组成特征一致;沟后组和猴家山组石灰岩分别形成于大陆岛弧和大洋岛弧环境。
The Neoproterozoic Gouhou Group and the Cambrian Houjiashan Formation limestone in northern Anhui were collected for systematic petrology and rare earth geochemical analysis. The origin and characteristics of rare earths in limestone were studied, With the inversion of distribution patterns, the paper discusses the Neoproterozoic-Cambrian tectonic setting in Northern Anhui. The results show that the total amount of rare earth elements in the limestone in the Gouhou Formation is relatively high (10.66-30.68 ppm), with significant differences between light and heavy rare earths, enrichment of light rare earths, and NdSN / YbSN ranging from 1.12 to 1.46. The total amount of rare earths in the limestone in the Houjiashan Formation is relatively low (1.63-7.79 ppm), the light and heavy rare earths are slightly different, and the light rare earths are slightly depleted. The LaSN / NdSNs range from 0.35 to 1.28 and are less affected by terrestrial sources. Abnormal, Ce anomaly and Y positive anomaly. The characteristics of REE in the Houjiashan limestone are slightly different from that of the Neoproterozoic seawater, which is consistent with the characteristics of the modern marine REE. The limestones of the Duguian and Houjiashan formations are formed on the continental island Arc and ocean island arc environment.