Character and Origin of Cambrian Hydrothermal Dolomite Conglomeration in the Northwestern Margin of Tarim Basin
详细信息
- 责任者：Zhang Juntao (Exploration & Development Research Institute ; SINOPEC ; Beijing 100083 ; China) ; Hu Wenxuan
- 刊名：Acta Geologica Sinica
- 出版年：2011
- 卷期：85(2)
- 关键词：白云岩 ; dolostone ; 白云石 ; dolomite ; 塔里木盆地 ; Tarim Basin
- 页码：p.234-245
- 图表：12 illus., 2 tables, 47 refs.
- 分类号：0803
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Hydrothermal conglomerated dolomite developed mainly in the Cambrian in the northwestern margin of the Tarim Basin and show distinct strata-bound feature. Geochemical analysis shows that hydrothermal dolomite has higher Ca/Mg values and Sr contents,slightly higher Fe,Mn and Ba contents, and more depleted δ18O values (-10.1‰~-12.2‰) than those of matrix dolomite (-6.1‰~-7.8‰). The δ13C values of hydrothermal dolomite in different locations vary greatly, but are similar to those of related host dolomite. The homogeneous temperatures of primary inclusions in the dolomites range from 90 ℃ to 120 ℃. The field geometry, petrography and geochemistry of hydrothermal dolomites indicate that higher temperature at which hydrothermal dolomite deposited resulted from the depth of deep burial and temperature gradient of the earth. Study of the forming mechanism of hydrothermal dolomite of this kind has some significance for understanding of evolution of the carbonatic rock reservoir in the Tarim Basin.