铵(氮)在岩石和矿物中地球化学行为研究进展

DEVELOPMENT OF THE GEOCHEMICAL BEHAVIOR OF AMMONIUM (NITROGEN) IN ROCKS AND MINERALS

地壳中的氮大都以NH4+储存在矿物中。由于成岩时含氮有机物质的分解作用,氮广泛分布在沉积岩和低级变质岩中;在岩浆岩和变质岩中,氮主要以NH4+存在于含钾硅酸盐(长石和云母类)中;岩浆岩的δ(15N)值和氮浓度明显地不同于沉积物和变沉积岩,主要是由于有机物的缺乏。具有明显铵含量的火成岩主要是含钾矿物的深成岩。因而NH4+可以作为一个“示踪元素”而用于成矿作用等方面的研究。文章还提出了未来的研究方向。

Nitrogen in earth crust, primarily as structural bound [NH4^＋ ], can substitute for K＋ in potassium-bearing silicate minerals such as muscovite, biotite, or K-feldspar and rocks. Compared to other geochemical systems （such as O, H,C, S etc. ）, nitrogen isotopic geochemistry has been rarely studied before but recently, the research of ammonium （nitrogen） isotopic geochemistry has developed rapidly. Value and concentration of δ（^15 N） in magmatic rock are quite different from those of sedimentary and meta-sedimentary rocks thus NH4^＋ can be used as a tracing element in the researches of ore-forming processes. This paper points out the future reseach direction.