西南石油大学学报(自然科学版) ›› 1998, Vol. 20 ›› Issue (3): 26-30.DOI: 10.3863/j.issn.1000-2634.1998.03.008

• 石油地质勘探 • 上一篇    下一篇

川东南地区志留纪稀土元素分布及其地质意义

张廷山1 陈晓慧1 兰光志1 俞剑华2 边立曾2 

  

  1. 1.西南石油学院勘探系四川南充 2.南京大学   
  • 收稿日期:1997-12-02 修回日期:1900-01-01 出版日期:1998-08-20 发布日期:1998-08-20
  • 通讯作者: 张廷山

Distribution and Geological Significance of REE in the Silurian of Southeast Sichuan

Zhang Ting-shan1 Chen Xiao-hui1 LanGuang-zhi1 Yu Jian-bua2 Bian Li-zeng2

  

  1. (Dept. of Petroleum Exploration,SWPI, Sichuan, 637001 )
  • Received:1997-12-02 Revised:1900-01-01 Online:1998-08-20 Published:1998-08-20
  • Contact: Zhang Ting-shan

摘要: 以川南綦江观音桥志留系剖面为代表,通过48个样品中子活化检测出的8种稀土元素分析,详细讨论了REE在该剖面上的分布演化特点及表现形式;研究了本区早志留世古海洋演化及古环境特点:(1)龙马溪组为滞流浅海盆沉积;(2)从龙马溪组到石牛栏组,其 REE逐渐减少,Ce anom从正异常向负异常演化,海平面趋于上升,至石牛栏组达最高;(3) REE分析结论与用沉积学、大地构造及其它地化分析所得出的结论相吻合,证明REE作为环境演化的“示踪剂”有较大意义。

关键词: 志留纪, REE, 分布, 演化, 川东南地区

Abstract: Instrument neutron activation analyses ( IN-AA) were carried out on 48 Silurian samples from Guanyinqiao section in Southeast Sichuan, and 8
REEs were detected. Based on the analytic results, a detailed discussion is made on the distribution and occurrence pattern of REEs and the characteristics of Early- Silurian oceanic evolution and sedimentary
environments in the area. And the following conclu-sion is reached: (1) the Longmaxi Formation was deposited in a shallow euxinic basin; (2) from the
Longmaxi Formation to the Shiniulan Formation,∑REE decreases gradually and Ce shifts from negative to positive anomalies, indicating a trend of rise of the
sea level. The highest sea level was reached during deposition of the Shiniulan Formation. (3) the con-clusions drawn from REE analyses are consistent with those from sedimentological, tectonic and other
geochemical studies, indicating that REEs can be used as indicators of evolution of sedimentary envi-ronments.

Key words: REE, Distribution, Sedimentary environ-ment, Silurian, Sichuan Basin

中图分类号: