北秦岭二郎坪群低压变质作用研究  

Low-pressure metamorphism of Erlangping Group in North Qinling Mountains

作　　者：张阿利[1] 魏春景[1] 田伟[1] 张翠光[1] 

机构地区：[1]北京大学地球与空间科学学院,北京100871

出　　处：《岩石矿物学杂志》2004年第1期26-36,共11页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目 (4 0 172 0 3 1)

摘　　要：在对二郎坪群低压变质带进行相图分析后发现 ,二郎坪群低压变质带是叠加变质带 ,低压变质作用是在早期中压变质的抬升过程中发生的 ,中压变质的温压条件为 0 .5～ 0 .6GPa、5 6 0～ 5 80℃ ,低压变质的压力为 0 .3～ 0 .4 5GPa ,红柱石十字石带的温度为 5 10～ 5 80℃ ,堇青石带为 5 90～ 6 2 0℃。 pT视剖面图在区分岩石中不同条件和期次的矿物组合及分析岩石温压演化历史和温压条件时显得更行之有效。It has been found through phase diagram analysis that the low-pressure metamorphic belt of Erlangping Group is a superimposed metamorphic belt. During the uplift of middle-pressure metamorphism, the low-pressure metamorphism took place. pT conditions of middle-pressure metamorhpism are 0.5～0.6 Gpa and 560～580℃. The pressure of low-pressure metamorphism is 0.3～0.45 GPa, and the temperatures of the andalusite-staurolite zone and the cordierite zone are 510～580℃ and 590～620℃, respectively. The pT pseudosection is a powerful tool for analyzing the pT evolutionary process and pT conditions when there exist several mineral assemblages formed in different periods and under different conditions.

关 键 词：低压变质作用 pT视剖面图 pT演化THERMOCALC程序 二郎坪群 

分 类 号：P588.33[天文地球—岩石学]