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熔积岩指的是侵入、混合到未固结或弱固结的湿沉积物中的熔浆分解、原位形成的一类特殊岩石。正确地认识该类岩石,有利于增进人们对岩浆-水(沉积物)相互作用过程的理解,恢复古环境。在青海南部沱沱河地区发现了一套角砾为撕片状、锯齿状及浑圆状的安山岩,胶结物为铁硅质组合的特殊熔积岩。研究表明,该熔积岩的角砾为岩浆遇水后快速淬火、裂解的产物,铁硅质组合为海底喷气沉积形成的含铁建造;且安山岩与含铁建造发生混合时,含铁建造尚未固结。该套熔积岩的发现,改变了长期以来对开心岭铁矿为火山热液交代安山岩而形成的认识,对于在矿区寻找VMS型矿床、区域内寻找海底热水喷流沉积型矿床具有重要的启示意义。
Sedimentary rock refers to a special type of rock that invades, mixes, and dissolves in unconfined or weakly consolidated wet deposits to form in situ. Correct understanding of this type of rock helps to improve understanding of the magmatic-water (sediment) interaction and restore the paleoenvironment. In the Tuotuohe area of southern Qinghai, a series of petrological and sedimentary andesite breccias have been found. The cements are special sedimentary rocks of iron-siliceous assemblage. The study shows that the breccia in the sedimentary rocks are the products of rapid quenching and cracking after the magma encounters water, and the iron-siliceous assemblages are iron-bearing structures formed by the sea-bottom jet deposition. When the andesite and the iron-containing structures are mixed, the iron content has not been built yet Consolidation. The discovery of this set of sedimentary rocks has changed the understanding that the Kaixinling iron ore has been formed by volcanic hydrothermal replacement of andesite over a long period of time. It is of great importance to search for the VMS deposits in the mining area and to search for the submarine hot water stream sedimentary deposit in the area Apocalyptic meaning.