阿拉善地区花岗岩中的同心多环带球体

The Poiyclic Sphroids in the Granites of Alxa Zuoqi Region

一九八一年,我们在内蒙古阿拉善左旗北部地区进行岩体调查时,在巴音诺尔公复式花岗岩体中发现一些球状体(图版Ⅰ—1),单个球体直径为10—14厘米(图版Ⅰ—3),常有破裂和剥落现象。球体之间为花岗质岩石。在通过球体中心的切面上,可以见到同心多环带构造,矿物呈辐射状生长。我们认为它是一种少见的具有重要地质意义的现象。

In making a survey of Bayinuoergong rock mass in the north of Alxa Zuoqi region,Nei Monggol(Inner Mongolia),the authors have discovered a kind of polyclic spheroids with diameter of 10-14cm.They occur in the Hercynian granites in the form of accumulation and may have been the paticular granitic inclusions resulted from the transformation of sedimentary nudules during the long geology history.The authors suggest the following sequence in development of transformation:development of sedimentary nudules-metamorphism-remel-ting and granitization.This sequence was supported both by the composition(mineral and chemistry)and the texture(or structure)of the spheroids and their round rocks.