The Identification Of Magmatic Origin Biotite To Mineralization

The family of mica minerals are widely distributed in nature,a kind of common rock forming minerals.Their macroscopic and microscopic morphology,chemical composition,crystal structure,physical properties and spectroscopy have obvious typomorphic characteristics.So they can become a kind of important and sensitive trace minerals.This article summarizes the typomorphic characteristics of mica systematically.The research is mainly focused on the chemical typomorphic characteristics of magmatic origin biotite,related to the mineralization about Au,Fe,Cu,Mo,W,Sn,U;Getting by the comparative study about the biotite in U-bearing and U-barren rock mass;moreover,getting by the comparative study about the biotite of typical rock mass in jiaodong area.The typomorphism of main chemical composition about the family of mica minerals can provide important information about the magma origin,rock formation,tectonic environment,physical and chemistry conditions of diagenesis and enrichment of ore-forming elements.The magmatic origin biotite associated with different mineralization,its change characteristics of main composition is regular,roughly divided into two categories: one kind is Mg-rich biotite in magmatic rocks related to the mineralization about Au,Fe,Cu,Mo,the other kind is Fe-rich biotite in magmatic rocks related to the mineralization about W,Sn,U.The biotite related to the mineralization about Au,Fe,Cu,Mo instructs: the magma comes from the mantle-crust interaction melting,the formation of ore deposit is related to syntexis-type granite(I-type),this kind of biotite is formed in shallow environment with high temperature and high oxygen fugacity.The biotite related to the mineralization about W,Sn,U instructs: the magma comes from the crust partial melting,the formation of ore deposit is related to reworking-type granite(S-type),this kind of biotite is formed in deep environment with low temperature and low oxygen fugacity.The biotite in U-bearing granite is mainly iron biotite-isiderophyllite,the type of rock belongs to peraluminous granite(S-type),the magma comes from the crust partial melting;The biotite in U-barren granite is mainly iron biotite,the type of rock belongs to the alkaline complex orogenic belts regions(I-type),the source rock material has the characteristics ofmantle-crust interaction melting.The biotite in U-bearing granite has the characteristic of relative low temperature and low oxygen fugacity.Guo Guling and San Foshan rock mass in jiaodong area over the same period with gold belong to Mg-rich biotite,The magma comes from the mantle-crust interaction melting,the rock type belongs to type I granite,Ling Long and Kun Yushan rock mass nothing to do with gold belong to Fe-rich biotite,between the crust partial melting and mantle-crust interaction melting,the rock type belongs to type I-S granite.The typomorphism of trace elements about the family of mica minerals can indicate the magma source material.Co and Ni play the tracer role for the study of metallogenic specificity about Cu,Mo,Au.The changes about F,Ba,Li,Rb,Cs can reflect the evolution trend of pegmatite and the degree of evolution differentiation.The typomorphism of rare earth elements can indicate the genesis of granite and the evolution trend about diagenesis and mineralizationThe typomorphism of morphology and micro morphology,crystal structure,physical properties,spectroscopy about the family of mica minerals can reflect metallogenic pressure,temperature and oxygen fugacity environment,the causes of rock and containing ore about rock mass.