【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；指出成分相近的斑岩在岩浆结晶动力学特征上的极细差别可能造成岩体含矿性明显不同更多还原

【Abstract】 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.更多还原