Analysis On Geologic And Geochemical Features And Metellogenic Prediction Of Qianmiaodi Granite In Taipus Area, Inner Mongolia

Qianmiaodi area is located in the northern margin of North China Block, and which belongs to eastern Zhengxiangbai-Doran gold lead-zinc poly-metals area of Proterozoic valley rift type copper-zinc-gold ore belt. And its great metallogenic potentiality is recognized by more and more scholars. However, only a little geological work has done in it, so the prospecting work has not been a great breakthrough.Through done deeply field geological survey, collected a lot of geological information, sampled a large number of rock and mineral samples and specimens, combined with the use of petrology, structural geology, mineralogy, mineral deposit geology, geochemistry, ore predictions, exploration science and other subjects of knowledge, started with the geological features of the northern margin of North China Block, stratigraphy, structure, magmatic rocks and their relations, the mineralization in Qiaomiaodi area have been detailed discussed. And then focused on the analysis of the area granite petrology and geochemistry, the metallogenic potentiality has been summed up, and the prospecting targets has been circled.By comparing the analysis of lithology characteristics and geochemical characteristics of Qianmiaodi granite and Shagou granite, the conclusion is induced:All of the granites are high silica (more than 56%), calc-alkaline (σis 0.98-1.57), metaluminous (A/CNK close to 1.1) and granodiorite-tonalite granite rock and K-feldspar granite, and their types are sodium-rich rocks as (Na2O more than K2O) ofⅠ-type intrusive rocks. And the former is partly like "S"-type granites, alkaline materials are more than the latter, and low differentiation index is the other feature (DI less than 88), Mg# index (0.20-0.33) andδEu (the Qianmiaodi granite for the weak negative anomalies to positive anomalies) show that the initial magmatic rocks derived from direct partial melting of lower crust. They are the magnetite series granite. They are low total REE (40.39×10-6-46.91×10-6), and REE differentiation is not obvious (ω(LaN)/ω(YbN) 1.68-6.35). First time, the thesis put forward the viewe that Qianmiaodi granite is mother rock of gold mineralization. And the invasion of the Qianmiaodi granite is provides the power source for the gold mineralization, and there is an excellent condition for mineralization in study area.Based on comprehensive analysis of the geological background, geological conditions, ore control factors and alteration of information, four prospecting targets is circled.