摘要
鞍子山超单元中的四个单元，不同程度地发育就位叶理及同源闪长质包体。从早期单元到晚期单元随着就位叶理强度的减弱，同源闪长质包体数量减少，压扁变形程度降低，二者产状一致。同源闪长质包体应变指数ｋ值总体为０＜ｋ＜１，属三轴压扁型应变椭球体，楔形侵入膨胀式就位机制。根据同源闪长质包体应变测量结果，运用Ｘ／Ｒｉ＝Ｙ／Ｒｆ公式计算出鞍子山超单元发生气球膨胀后的体积比初始体积大１．７０倍，岩浆体积横向拓宽了７０％。
Anzishan ultra unit can be divided into 4 units:Daheishantun unit(J 3D),Jiangyoufang unit(J 3J),Bandao unit(J 3B) and Huangbaishu unit(J 3H), in which emplacement foliations and homology diorite inclusions developed at defferent degrees.From early to late stages,with the intensity of the emplacement foliations got weaken and the number of homology diorite inclusions got fewer,the flattening deformation degree of the ultra unit was getting lower, but the attitude of these foliations and inclusions kept consistent.The strain index k value of homology diorite inclusions,overall being between 0 and 1,shows that the strain type of Anzishan ultraunit is of a triaxial flatten strain ellipsoid( X>Y>1>Z ).Analysis on the overall shape and the regional tectonic location of the ultra unit,the structural development degrees in various units and their surrounding rocks,features of deformation and rotation direction of the dirorite inclusions, and optical characteristics of mineal deformation on orientated sections indicate that the emplacement mechanism of the ultra unit magma is wedge form intrusive expansion style.According to the strain measurement results of homology diorite inclusions,and by the formula X/R i =Y/R f , the existing volume of the ultra unit after balloon expansion is 1.7 times of the original volume when the ultra unit magma intruded ,and the laterally widen volume has been expanded 70%.
关键词
鞍山子
超单元
应变类型
横向拓宽体积
花岗岩
anzishan
ultra unit
emplacement
foliation
homology diorite inclusion
strain type
laterally widen volume
