安徽沙溪含和不含铜(金)矿斑岩斜长石斑晶粒度统计及其岩浆结晶动力学和成矿意义  

Size Statistics of Plagioclase Phenocrysts in Mineralized and Barren Porphyries in Shaxi Porphyry Copper Gold Deposit, Anhui Province and Its Significance for Studying Magma Crystallization Kinetics and Ore Forming Process

作　　者：徐文艺[1] 傅斌[1] 任启江[1] 胡文暄[1] 徐兆文[1] 

机构地区：[1]南京大学地球科学系

出　　处：《岩石学报》1997年第2期180-188,共9页Acta Petrologica Sinica

基　　金：国家自然科学基金

摘　　要：通过对沙溪矿区含矿与不含矿斑岩中斜长石斑晶的粒度统计，计算出平均矿物粒度（Ｓ）、矿物分布密度（Ｄ）及矿物分布均匀度（Ｈ）；再根据晶体大小分布理论（ＣＳＤ），计算出斜长石的晶体生长速率、成核密度及成核速率等岩浆结晶动力学参数；发现含矿斑岩较无矿斑岩有高的成核密度和成核速率，而晶体生长速率则较低；Through size statistics of plagioclase phenocrysts in mineralized and barren porphyries in Shaxi porphyry copper gold deposit, the three parameters, i.e. average grain size ( S ),grain density ( D ) and homogeneity of distribution ( H ), have been calculated. On the basis of the crystal size distribution (CSD) theory, the growth rates, nucleation density and nucleation rates of plagioclase have been worked out. Comparing these parameters of mineralized porphyries with those of barren ones, we find that nucleation rates and nucleation density of mineralized porphyries are higher than those of barren ones, but crystal growth rates of mineralized porphyries are slower. This study shows that a slight difference of the characteristics of magma crystallization kinetics among the porphyries having similar petrochemical and geochemical composition, may result in obviously distinctive ore bearing potentiality.

关 键 词：斜长石 斑晶粒度 斑岩 含铜矿 岩浆结晶 含金矿 

分 类 号：P588.13[天文地球—岩石学] P578.968[天文地球—地质学]