胶东招平断裂带变形变质温度的显微构造分析

招平断裂带是胶东西北部金矿集中区一条重要的含金剪切带,断裂带岩石主要矿物长石、石英和方解石的显微构造具有脆-韧性变形共存的特点。通过矿物脆-塑性变形转换温度、石英位错特征以及动态重结晶石英颗粒分形统计等方法,估算出断裂带变形温度在150~400℃,局部达到400~500℃。运用显微构造方法估算的温度与断裂带热液蚀变矿物流体包裹体测温方法得出的结论基本一致;因此,显微构造分析方法可以广泛应用于含金剪切带的变形变质测温。

Microstructural analysis on the deformation and alteration temperatures of Zhaoping Fault Zone in Jiaodong Peninsular

Zhaoping Fault Zone is one of the most important gold-hosting shear zones in Northwestern Jiaodong where gold deposits are concentrated.The microscopic deformation of the main minerals,i.e.feldspar,quartz and calcite,in the fault zone show the characteristics of brittle-ductile deformation.The results of temperature estimation u sing the methods of brittle-plastic transition temperature of minerals,the dislocation characteristics and the fractal statistics of the dynamic recrystallized quartz indicates that the fault zone deformational temperature is about 150 ℃ to 400 ℃ and locally reaches 400 ℃ to 500 ℃.This is basically consistent with the results obtained by the thermometry using the fluid inclusions of hydrothermal alteration minerals in fault zones.Therefore,the microstructural analysis can be widely used in the estimation of the deformation and alteration temperature of gold-bearing shear zones.