成矿裂隙的成生和充填及其脉动性

成矿裂隙(简称矿裂)和自然界其他事物一样,有它自己发生、发展以至消亡的历史。矿裂与无脉体充填的断裂构造区别在于:它直接表现出来的是矿脉(或岩脉)。矿裂的发展过程可分为三个阶段:成生阶段、张开充填阶段和破坏阶段,各阶段的应力状况和表现形式可以不同。

GENESIS AND FILLING OF ORE-FORMING FRACTURES AND THEIR PULSATORY NATURE

Starting from the viewpoint of development, this paper divides the history ofore-forming fractures into three stages——the genetic stage, the gaping and fillingstage and the destructive stage——and an analysis is made with examples on thetwo former stages related to ore-forming. The genetic stage of ore-forming fractures results principally from horizontal compressive stress, and deformation-fracturing process reflects in general the stereoscopic characteristics. The gaping and filling of ore-forming fractures is formed chiefly under conditions of structural tension, which is associated with the uneven uplift of an ore-forming region. Consequently, the ore-forming fracture system is motivated by compressive stress and completed by tensile stress.Ore-forming fractures are closely related with veined ore-deposits, which indicate that both ore-forming structural activities and metallogenetic process often take place many times intermittently, in other words they are of a pulsatoty nature. Two types of characteristic structural pulsation are recognized: 1. multiple genesis of ore-forming fractures and 2. multiple gaping and filling of ore-forming fractures in a single genesis.Finally, the tectonic origin of the problems treated above and the significance of their application to practical work are also discussed.