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J4 ›› 2011, Vol. 17 ›› Issue (3): 415-.

• 岩浆作用、成矿作用与地球动力学专栏 • 上一篇    下一篇

花岗岩中常用压力计的应用评述

李小伟, 黄雄飞, 黄丹峰   

  1. 北京大学 地球与空间科学学院
  • 收稿日期:2011-04-22 修回日期:2011-08-09 出版日期:2011-09-20 发布日期:2011-09-20
  • 作者简介:李小伟,男,1985年生,在读博士生,矿物学、岩石学、矿床学专业;E-mail: lixiaowei@pku.edu.cn
  • 基金资助:

      国家973项目(2009CB421002,2011CB403102);国家自然科学基金项目(40873023,40830317,40973062,40973026);中国地质调查局工作项目(1212011121260,1212011121066);中央高校基本科研业务费专项资金项目(2010ZD02)和教育部新世纪优秀人才项目(NCET-10-0711)联合资助

Review on Application of Geobarometry for Granitic Rocks

 LI Xiao-Wei, HUANG Xiong-Fei, HUANG Dan-Feng   

  1. School of Earth and Space Sciences, Peking University
  • Received:2011-04-22 Revised:2011-08-09 Online:2011-09-20 Published:2011-09-20
  • About author:Li Xiaowei, Ph.D. candidate. E-mail: lixiaowei@pku.edu.cn

摘要:

       本文简要讨论了花岗岩中常用压力计的应用限制条件和误差。对于钙碱性花岗岩推荐使用角闪石全铝压力计;对低
压矿化岩体建议使用黑云母全铝压力计即可;奥长环斑花岗岩中可应用富铁斜方辉石-铁橄榄石-石英组合压力计;存在两
种长石和石英平衡共结的花岗岩可利用Q-Ab-Or-H2O相图获得它们的共结压力。花岗岩矿物中流体包裹体的内压可以通过
热力学状态方程或者拉曼光谱获得;特殊的岩浆矿物如绿帘石有时候也可以指示岩浆结晶时所处的最低压力。此外,通过
THERMOCALC计算的视剖面是约束共生矿物组合及熔体形成温压条件的最后方法。

关键词: 花岗岩, 压力计, Q-Ab-Or-H2O相图

Abstract:

       This paper briefly and critically discusses several common geobarometers applied  to granitic systems, especially
the specific  rock  types, and  their  limitation and error analysis. The Al-in-hornblende barometer can be applied  to calc-alkaline granites and  is  suitable  for  low-pressure mineralized granitic pluton. The Fe-rich orthopyroxene-fayalite-quartz assemblage barometer can be used  to calculate  the crystallization pressure condition of  rapakivi granites, and  the crystallization pressure of coexisting alkali  feldspar, plagioclase and quartz can be obtained via projecting onto  the Q-Ab-Or-H2O phase diagram  for granites. The hydrostatic pressure of  fluid  inclusion  in granites can be acquired by  thermodynamic state equations or    raman spectroscopy. Some  indicative minerals  like magmatic epidote  sometimes can constrain  the  lower pressure  limit. Moreover, the pseudosection calculated by THERMOCALC   eventually can define  the pressure scope  for a specific coexisting mineral assemblage and specific pressure and temperature.

Key words:  granite, geobarometry, Q-Ab-Or-H2O phase diagram

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