喀拉通克铜镍矿床南带控矿构造与岩浆侵位动力学

Ore-Controlling Structures and Magmatic Transport Dynamics in the Southern Belt of Kalatongke Cu-Ni Deposit

喀拉通克矿床为中亚造山带中典型岩浆型铜镍硫化物矿床,矿区内发育NW向褶皱及NW向、NNW向、NE向断裂构造,基性含矿岩体与其关系密切。通过对矿区南岩带含矿基性岩体进行三维形态分布和坑道内断裂构造与矿体接触关系分析,认为矿区内岩矿体分布受NW向和NNW向构造控制,岩矿体具NNW向膨大变宽、NW向挤压变窄特征。矿区岩矿体分布及形态是在右行挤压剪切产生的NW和NNW向两组断裂控制下侵位的,含矿基性岩浆侵位时矿区处于挤压构造背景。指出构造挤压应力被中间岩浆房岩浆转为岩浆内压,岩浆内压的增加驱动岩浆房中分异的含矿岩浆依次往上搬运与侵位。这是铜镍矿床基性-超基性岩浆侵位的新动力学机制。

The Kalatongke deposit is a typical Cu-Ni sulfide deposit in Central Asian Orogenic Belt(CAOB).There are northwest trending folds and northwest(NW),north northwest(NNW)and northeast(NE)trending faults in Kalatongke mining area,and the basic ore bearing rock mass is closely related to it.Through the analysis of the three-dimensional shape distribution of the ore bearing basic rock mass in the Southern rock belt of the mining area and the contact relationship between the fault structure in the tunnel and the ore body,it is considered that the distribution of the rock ore body in the mining area is controlled by the NW and NNW structures,and the rock ore body has the characteristics of expansion and widening in NNW direction and compression and narrowing in NW direction.The distribution and shape of rock ore bodies in the mining area were emplaced under the control of two groups of faults in NW and NNW directions generated by dextral compressive shear.The mining area was in a compressive tectonic background when the ore bearing basic magma was emplaced.It is pointed out that the tectonic compression stress is transformed by the magma in the middle magma chamber into intra magma pressure,and the increase of intra magma pressure drives the migration and emplacement of the differentiated ore-bearing magma in the magma chamber.This is a new dynamic mechanism of basic-ultrabasic magmatic emplacement in Cu-Ni deposits.