Thermodynamics Interpretation for Albitization of Detrital K-Feldspar of T3x2 Member in Western Sichuan Depression
详细信息
- 责任者：Huan Jinlai (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Huang Sijing
- 刊名：Fault-Block Oil and Gas Fields
- 出版年：2011
- 卷期：18(3)
- 关键词：热力学 ; thermodynamics ; 钾长石 ; K-feldspar ; 钠长石化 ; albitization ; 四川盆地 ; Sichuan Basin
- 页码：p.289-292
- 图表：illus., 13 refs.
- 分类号：1003
- issnNo：ISSN1005-8907
- isbnNo：CN41-1219/TE
摘要
Based on the calculation of chemical thermodynamics and the data of current formation water,the thermodynamic principle and diagenetic mechanism of albitization of detrital K-feldspar of T3x2 Member in western Sichuan Depression were discussed in this paper.The results show that if the content of K+ and Na+ keeps constant,there will be a growing tendency for albitization of K-feldspar with the increase of buried depth and temperature.The equilibrium state of fluid and K-feldspar and albite is another factor controlling whether albitization of K-feldspar can carry out if temperature is unchanging;influenced by acid fluids in overburden mudstone strata,the plagioclase of T3x2 Member in western Sichuan Depression is largely dissolved from syngenetic period to the early stage of diagenesis,but the Na+ generated by dissolution of plagioclase is not the main source of Na+ of albitization of K-feldspar in later period because it is removed in the way of spread and convection;with the further increase of buried depth(at 120-140 ℃),the system approaches to be closed and acid fluids in overburden mudstone strata can hardly affect the inside of thick-bedded sandstone,which hinders the dissolution of K-feldspar for the more limited of H+.Meanwhile,the illitization of smectite consumes K+ and provides extra Na+ to formation water,the albitization of K-feldspar turns to be a reaction closely associated with the illitization of smectite at this time,it does not stop until the smectite completely consums out.Thus,the illitization of smectite is the major route of migration of K+ and Na+ in the process of albitization of K-feldspar of T3x2 Member in western Sichuan Depression.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |