【摘要】 个旧花岗岩,从斑状黑云母二长花岗岩→中粗粒黑云母钾长花岗岩→二云母碱长花岗岩构成了较完整的同源多阶段演化系列,岩浆是以分离结晶方式演化的。不同类型花岗岩的lg(Rb/Sr)-lgSn,lg(Rb/Ba)-lgSn,lgLa-lgSr,lgCe-lgSr,lgEu-lgSr等具有很好的线性关系,REE分布模式的演化也反映了岩浆分异特征。晚期二云母碱长花岗岩是强烈分异的锡多金属矿化花岗岩,其以高Rb/Sr,Rb/Ba比值和低K/Rb、∑Ce/∑Y比值以及Eu强烈亏损为特征。更多还原

【Abstract】 The evolution characteristics of Gejiu granites, Yunan Province are described in terms of their petrology, especially their trace element and REE geochemistry. The three major types of Gejiu granites: the porphyritic biotite monzonitic granite (stage Ⅰ), the medium-grained biotite-K-feldspar granite (stage Ⅱ), and the two-mica alkali-feldspar granite (stage Ⅲ) are thought to have been formed successively from the same magmatic source through fractional crystallization (Rayliegh fractionation), because linear correlations are observed in log(Rb/Sr)-logSn, log(Rb/Ba)-logSn, logLa-logSr, logCe-logSr, logEu-logSr, etc. In addition, the evolution of REE distribution patterns in these three major types of granites also reflects the magmatic differentiation features of Gejiu granites. Of granites of the three major stages, the two-mica alkali-feldspar granite of stage Ⅲ, underwent strong differentiation, and thus has the closest genetic relationship with Gejiu Sn-polymetallic ore deposits. Such Sn-polymetal mineralized granites are characterized by high Rb/Sr and Rb/Ba ratios, low K/Rb and ΣCe/ΣY ratios, and a remarkable Eu depletion.更多还原