摘要
对采自五台群底部的角闪黑云斜长片麻岩样品进行了较为细致的研究工作，探讨了样品遭受变质变形的温度条件及样品中变形双晶类型和斜长石的晶格组构型式。研究表明：变形时的温度条件是影响变形双晶类型的主要因素，高温变形条件下趋向于形成肖钠双晶。随着变形温度的变化，斜长石的晶格优选和双晶滑移系也发生相应变化。本文论及的斜长石组构特点是较高变形温度条件下形成的一种新的组构类型。
Plagioclase is a major rock-forming mineral,but studies on its fabric isless emphasized than that of quartz or calcite. Some new conclusions have been gotthrough study on the sample W9216 from Wutai Group.The type of twinning developedin plagioclase is related to deformation temperature,pericline twin is dominant atdeformation temperature higher than 600℃,albite twin is prevailing at lowertemperature. Our sample shows,that at 620℃, the(100)plane of plagioclase parallelsto schistosity and the prefered orientation of a-axis is perpendicular to the stretching,the prefered orientation of b-axis parallels to schistosity and is perpendicular to,thestretching direction. This lattice fabric pattern differs from the works of formerresearchers. It means that the deformation fabric of plagioclase also depends on thedeformation temperature,there are different prefered orientation with varioustemperature.
基金
国家自然科学基金
关键词
斜长石
变形温度
肖钠双晶
晶格组构
角闪岩
plagioclase,deformation temperature,pericline twin,lattice fabric
