秦岭杂岩中牛角山花岗质古深成岩体变形作用的初步研究及其构造意义  

A PRELIMINARY STUDY ON DEFORMATIONS OF THE NIUJIAOSHAN GRANITIOD PLUTON IN THE QINLING COMPLEX AND ITS SIGNIFICANCE

作　　者：王涛[1,2] 王晓霞[1,2] 李伍平 

机构地区：[1]西北大学地质系 [2]西安工程学院资源系

出　　处：《西安工程学院学报》1998年第3期5-10,共6页Journal of Xi'an Engineering University

基　　金：国家自然科学基金

摘　　要：该岩体已变形改造为线状花岗质片麻岩体。除残留少量的岩浆流动组构外，主要表现为岩体定位后期或固结稍后的高温固态变形；以强烈的条带状片麻理发育为特征，并发育流褶皱、面理置换、小型韧性剪切带等。斜长石、钾长石多呈眼球状、条带状，为动态重结晶集合体；石英多呈矩形带状；变形温度在７００℃～５５０℃。应变测量显示其变形为压剪应变形，ｖ＝０．１９～０．５８，强度ＥＳ＝１．４６～１．２２。该岩体的变形揭示了该区晋宁期区域变形的特点和强度，并限定了其峰期变形时间。The granitiod pluton was deformed into granitiod gneiss. The deformations were characterized by high temperature state deformation during the later stage of the emplacement or slight later emplacement, in addition to some preserved fabrics formed by magmatic flow. Banded foliations, flow folds, foliation displacement and small scale ductile shear zones were developed. Plagioclases and k feldspars occured in dynamic recrystallized aggregates with the form of lens or band. Quartzs also occured in band. The deformation temperature was about 700～550 ℃. Strain measurements show that the types of the deformations are oblate simple shear (v=0.19～0.58), and the strength is high (E S=1.46～1.22) . The deformations of the pluton indicate the characteristics and strength of the regional deformations during the Jinning period, and constrain the period of its strongest deformation.

关 键 词：古岩体 秦岭 杂岩 花岗质深成岩体 变形作用 

分 类 号：P588.36[天文地球—岩石学]