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位于合肥盆地南部安徽肥西地区的中生代地层,包括防虎山组、园筒山组和周公山组,主要由砂岩组成。虽然初步研究表明物源主要来自大别造山带,但是,进一步限制物源区类型、建立和大别山造山带构造单元之间的对应关系、查清大别山造山带和华北陆块作为物源在研究区的影响范围,具有重要地质意义。本文根据砂岩主元素、REE和微量元素研究表明,研究区砂岩主要是杂砂岩、岩屑砂岩和长石砂岩,主元素含量比较接近晚元古代造山带砂岩。砂岩非常一致的REE模型,基本显示了同一的物源和相同的构造背景。REE和微量元素特征显示肥西地区中生代砂岩物源主要为佛子岭群和卢镇关群,大别杂岩的影响比较局限,更没有来自华北克拉通的物质。同时,在中生代,大别山造山带的物源没有影响到华北陆块南部沉积。Th-Co-Zr/10和Th-Sc-Zr/10判别图以及微量元素比值都支持碎屑岩的物源形成于大陆岛弧构造背景,这不仅验证了已有的结论,同时也揭示了在造山带周缘盆地中碎屑岩地球化学特征具有构造背景的继承性。
The Mesozoic strata, located in the Feixi area of Anhui Province in the south of the Hefei Basin, include the anti-Hulushan Formation, the Yuanbaoshan Formation and the Zhougongshan Formation, which are mainly composed of sandstone. Although preliminary studies indicate that the source of the source rocks mainly come from the Dabie orogenic belt, the type of the provenance area is further limited and the corresponding relationship with the tectonic units of the Dabie orogen is established. The Dabieshan orogenic belt and the North China terrane are identified as provenances in the study area The scope of influence, has important geological significance. Based on the main elements of sandstone, REE and trace elements, the study shows that the sandstone in the study area is mainly composed of miscellaneous sandstone, lithic sandstone and feldspar sandstone, and the main element content is relatively close to the Late Proterozoic orogenic belt sandstone. The sandstone very consistent REE model basically shows the same provenance and the same tectonic setting. The characteristics of REE and trace elements show that the source rocks of the Mesozoic sandstones in Feixi area are mainly Fuziling Group and Luzenguan Group. The influence of Dabie Complex is rather limited and there is no substance from North China Craton. Meanwhile, in the Mesozoic, the provenance of the Dabieshan orogenic belt did not affect the sedimentation in the southern part of North China. Th-Co-Zr / 10 and Th-Sc-Zr / 10 discrimination diagrams and trace element ratios support the origin of clastic rocks formed in the continental island arc tectonic setting, which not only validates the existing conclusions, but also reveals The geochemical characteristics of clastic rocks in the peripheral margin of the orogenic belt have tectonic background inheritance.