欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
目的探讨天水地区上泥盆统大草滩群变砂岩形成的构造环境。方法利用砂岩常量元素、微量元素和稀土元素地球化学分析，结合区域地质研究。结果天水地区上泥盆统大草滩群主要为变砂岩、粉砂岩、泥质岩石，其中的变砂岩地球化学具有相对低SiO2，Na2O，高TiO2，MgO，Fe2O3，Al2O3的特征；富集Nb，Co，La，Ce，Nd，亏损Sc，Th，Hf以及La／Th，La／Sc，Th／Sc，Ti／Zr，Zr／Hf等特征参数与大陆岛孤和活动大陆边缘构造环境沉积物相似。结论天水地区上泥盆统大草滩群中的变砂岩碎屑来源于活动大陆边缘。
英文摘要：
Aim To study tectonic setting of the meta-sandstones of the Upper Devonian Dacaotan group in the Tianshui area. Methods The analysis of geochemical data about the major,trace and rare elements of sandstone, is combined with the investigation of regional geology. Results The Upper Devonian Dacaotan group in the Tianshui area is composed of metasandstones, aleurolites and pelites. The geochemistry of the metasandstones is characterized by low SiO2and Ne2O contents, and high TiO2, MgO, Fe2O3 and Al2O3 contents. In addition, they are also Enriched in Nb, Co, La, Ce and Nd, and depleted in So, Th and Hf. All these characteristics with the ratios of La/Th, La/Sc,Th/Sc,Ti/Zr, Zr/Hf are similar to that of the sandstones deposited in a continental island -arc and active continental margin setting. Conclusion Based on the study of the regional geology and all above evidences, it is suggested that the provenace of meta-sandstones of the Upper Devonian Dacaotan Group in the Tianshui Area is active continental margin setting.
同期刊论文项目
同项目期刊论文
期刊信息
位置：