论浅成侵入体伴生隐爆角砾岩及其在金属矿床形成中的作用

The Role of Cryptoexplosive Breccia Associated with Hypabyssal Intrusive in Metallization

在地壳内,围绕含矿浅成侵入体广泛地分布着爆发岩。来自深部的含矿岩浆,沿着运移通道上升至浅成带,进行着迅速而不均匀的岩浆分异和结晶作用,在岩浆柱顶部形成富含碱质和挥发分的热液以及盈余能量,并在岩浆作用结束阶段导致突然的爆发现象和岩浆角砾岩化作用,含矿热液渗入岩浆角砾岩化作用形成的裂隙中,进行着热液变质作用,并在有利条件时发生矿化。因为角砾岩化作用带同时是岩石强烈热液变质带,往往也是矿化作用带,角砾岩化作用、热液变质作用和矿化作用也是几乎同时先后进行的,角砾岩化与岩浆期后热液活动和矿石富集有着紧密的时空关系。所以在正常情况下,隐蔽爆发伴有含矿岩浆的剧烈分异,并且是产生热液成矿系统的最普遍的方式之一。

Cryptoexplosive breccia often occurs around ore-bearing hypabyssal magmatic intrusive.Ore magma undergoes rapid and uneven magmatic differentiation and crystallization during the ascending migration pathway to the shallow zone.A hydrothermal solution rich in alkali and volatile matter is formed at the top of the Magma Column.At the end stage of magmatism,sudden eruption and magmatic brecciation occur.The ore-bearing hydrothermal solution seeps into the fissures formed by magmatic brecciation.Thus hydrothermal metamorphism is carried out and mineralization occurs under favorable conditions.The brecciation is closely related to postmagmatic hydrothermal activity and ore-formation.Cryptoexplosion is often associated with violent differentiation of ore magma which is one of the most common ways of generating hydrothermal ore-forming systems.