地学前缘 ›› 2016, Vol. 23 ›› Issue (4): 29-45.DOI: 10.13745/j.esf.2016.04.003

• 大别造山带构造与成矿 • 上一篇    下一篇

北淮阳东段佛子岭群变质岩地球化学特征及其地质意义

 柴广路, 李双应   

  1. 合肥工业大学 资源与环境工程学院, 安徽 合肥 230009
  • 收稿日期:2015-12-20 修回日期:2016-01-12 出版日期:2016-07-15 发布日期:2016-07-15
  • 通讯作者: 李双应(1956—)，男，教授，博士生导师，沉积地质学和地层学专业。E-mail:lsystevsn@126.com
  • 作者简介:柴广路(1989—)，男，博士研究生，古生物与地层学专业。E-mail:chaiguanglu001@163.com.
  • 基金资助:

    中国地质调查局项目(12120113094300)；安徽省公益性地质工作项目(2014-g-9)；国家自然科学基金项目(41172097)

CHAI Guanglu, LI Shuangying. Geochemical characteristics and geological implications for the metamorphic rocks of Foziling Group in Eastern of North Huaiyang Tectonic Belt.

 CHAI  An-Lu, LI  Shuang-Ying   

  1. School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
  • Received:2015-12-20 Revised:2016-01-12 Online:2016-07-15 Published:2016-07-15

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摘要：

北淮阳地区的佛子岭群是一套经受了多次变形、变质作用的低级变质岩系。佛子岭群主量元素平均含量为SiO2 75.42%、Al2O3 8.13%、MgO 1.52%、Fe2O3 3.23%、Na2O 1.61%、K2O 1.67%、TiO2 0.41%；特征微量元素 Th、U、Hf、Sc、Zr、Y 平均含量分别为8.49×10-6、1.47×10-6、4.85×10-6、170.66×10-6、193.69×10-6、18.97×10-6；Th/U、La/Y、Th/Sc、La/Sc比值分别为4.92、3.56、1.51、1.38；∑REE含量125.3×10-6，δEu=0.67，轻稀土富集，La/Yb=14.99，(La/Yb)N=10.11。下部的祥云寨组主要为一套变质石英砂岩，原岩为砂岩和杂砂岩，构造环境以被动大陆边缘为主，物源以石英岩沉积岩物源区为主，并显示了亲扬子陆块的特征。而诸佛庵组和潘家岭组为一套云母石英片岩、石英云母片岩和二云片岩，原岩为杂砂岩、亚岩屑砂岩、岩屑砂岩及页岩，构造背景为大陆岛弧和活动大陆边缘，物源区主要为石英岩沉积岩物源区和长英质火成岩物源区，并显示了亲华北陆块的特征，表明佛子岭群经历了由扬子北缘被动大陆边缘向华北南缘活动大陆边缘的构造转化。

关键词: 地球化学, 原岩恢复, 构造背景, 佛子岭群, 北淮阳

Abstract:

Foziling group of North Huaiyang is a set of lower metamorphic rocks which had undergone multiple deformations and metamorphism. The average contents of Foziling Group are SiO2 75.42%, Al2O3 8.13%, MgO 1.52%, Fe2O3 3.23%, Na2O 1.61%, K2O 1.67%, TiO2 0.41%; a part of characteristic trace elements like Th, U, Hf, Sc, Zr, Y have average of 8.49×10-6, 1.47×10-6, 4.85×10-6, 170.66×10-6, 193.69×10-6 and 18.97×10-6, respectively; and the ratio of Th/U, La/Y, Th/Sc, La/Sc are respectively 4.92, 3.56, 1.51 and 1.38; the average of ∑REE is 125.3×10-6, δEu is 0.67, light REE enrichment, La/Yb is 14.99 and (La/Yb)N is 10.11. The lower part of Foziling group which named Xiangyunzhai Formation is a set of metamorphic quartz sandstone whose protolith are sandstone and greywacke rock, and it has a tectonic setting of passive continental margin and a provenance of quartzite and sedimentary rocks which indicates the Yangtze(phile) geochemical features. However, the upper part of Foziling Group metamorphic rocks including Zhufoan Formation and Panjialing Formation mainly consists of a set of quartzmica schist, micaquartz schist, mica schist and minor quartz quartzite and its protolith are greywacke, sublitharenite, litharenite and shales. Its tectonic setting is continental island arc and active continental margin and its provenance are mainly quartzite sedimentary rocks and felsic igneous provenance. That shows the characteristics of North China Plateaffinitive. The above information suggests that Foziling Group has undergone the tectonic transformation from the passive continental margin of northern Yangtze to the active continental margin of southern margin of North China.

Key words: geochemistry, protolith reconstruction, tectonic setting, Foziling Group, North Huaiyang

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