韧性剪切带中含金石英脉的就位机制

本文以韧性剪切带中含金石英脉的地质特征分析为基础。重点讨论:a.绿片岩相—低角闪岩相环境中的韧性剪切带内,变形岩石的韧—脆性转变既受温度、压力条件控制,又受高压流体相的广泛介入影响。对于多阶段金矿化过程,流体相的存在对岩石力学性质的转变具有更重要的意义;b.Roberts(1987)论述的含矿Riedal裂隙系(D、P、R、R′和T、P′)中不同类型裂隙内含金石英脉的就位机制有很大的差异;c.Ramsay的破裂—愈合机制可以很好地解释沿R、R′、T和某些沿D、P就位的含金石英脉的形成;d.本文作者提出液压扩容破裂机制是沿D、P方向就位的某些含金石英脉的重要就位过程。

THE EMPLACEMENT MECHANISM OF AURIFEROUS QUARTZ IN THE DUCTILE SHEAR ZONES

In this paper, on the basis of the geological features of auriferous quartz in the ductile shear zones, the following aspects are discussed. A. In the ductile shear zone of the greenschist facies and low amphibolite facies, ductil-brittel deformation of the rocks are controlled by the temperature and pressure as well as is intrusived by the pressure fluid phase. To the stage of gold minerization, the existence of the fluid phase has an important significance for the change of nature of rock mechanics. B. Roberts (1987) discussed ore-bearing Rieded system of fiffures (D. P. R. R' and T. P') and pointed out that the emplacement mechanism of auriferous quartz has a quite difference in different type fissures. C. The mechanism of Ramsay' s fracturehealing can explain the form of auriferous quartz along the R, R', and D. D. The author proposed that liquid epitaxy fracture mechanism is an important emplacement process of some auriferous quartz along the D, P direction.