估算钙碱性长英质侵入岩结晶压力的地质压力计评述  

A discussion on the geobarometers applied to estimate the crystallization pressure of calc-alkaline felsic intrusions

作　　者：徐鸿雪 汪洋[1] XU Hongxue;WANG Yang(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing,100083)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地质论评》2023年第6期2325-2334,共10页Geological Review

基　　金：中国地质调查局地质调查项目(编号:D1912)的成果。

摘　　要：笔者等对4种常见的矿物压力计(角闪石全铝压力计、黑云母压力计、榍石压力计和“石英”压力计)的适用性进行了经验性检验。基于国内外典型钙碱性长英质岩体的矿物化学和全岩化学成分数据,采用不同压力计估算岩体侵位压力,并与角闪石全铝压力计结果对比。结果表明:角闪石六次配位Al压力计与广泛使用的角闪石全铝压力计的估算值存在系统相关性;榍石压力计计算的压力与角闪石全铝压力计的估计结果相关性较为显著;基于Qtz—Ab—Or简并花岗岩体系的“石英”压力计可以用于估计准铝质—弱过铝质钙碱性(狭义)花岗岩的结晶压力。但是,经验性的黑云母压力计和基于实验数据的黑云母压力压计均不能很好地复现角闪石全铝压力计的结果。黑云母压力计不适用于估算钙碱性侵入岩的结晶压力。In this review,four commonly used geobarometers,i.e.,aluminum-in-amphibole,biotite,sphene(titanite),and“quartz”barometers,are testified for their suitability to estimate the crystallization pressure of calcalkaline felsic intrusive rocks.Using a compilation of mineral chemistry and whole-rock composition data from some typical calc-alkaline felsic intrusions in home and abroad,we found that there are systematic correlations between the results from the new proposed octahedral aluminum-in-amphibole barometer and those from the typical aluminum-in-hornblende barometer.Meanwhile,the pressures calculated by the sphene(titanite)Al2O3 content barometer are finely correlated with the estimations from aluminum-in-hornblende barometer.The“quartz”barometer which is established on the Qtz—Ab—Or hapalogranitic system,can be only used to constraints the crystallization pressures of the metaluminous to weak peraluminous granites(s.s.).However,neither the empirical biotite barometer nor the experiment-derived biotite barometer replicate the aluminum-in-amphibole barometry for natural rocks.Accordingly,it is suggested that the barometry from biotite is not suitable for calculating the crystallization pressure of calc-alkaline felsic intrusive rocks.

关 键 词：钙碱性长英质侵入岩 结晶压力 角闪石铝压力计 黑云母压力计 榍石压力计 “石英”压力计 

分 类 号：P588.12[天文地球—岩石学] P575[天文地球—地质学]