松潘—甘孜造山带中巴西金-矽卡岩矿床成矿热液系统演化的(REE、Sr、O)证据

本文通过对巴西典型金-矽卡岩矿床的解剖，探讨了成矿流体来源、组成演化，以及流体和岩石之间的质量转移程度和机理的信息，揭示金成矿过程中成矿流体演化的规律。研究认为，成矿作用两阶段的成矿流体分别为变质流体和大气降水，它们在开放系统中水岩质量比分别为0．02，2．11，并且获得矽卡岩可能是由围岩转向岩体方向的变质流体交代形成的认识。

REE AND ISOTOPE (Sr,O) DATA FOR THE EVOLUTION OF ORE-FORMINO HYDROTHERMAL SYSTEM:EVIDENCE FROM THE BAXI GOLD-SKARN DEPOSIT IN SONGPAN-GANZI OROGENIC BELT,SICHUAN,CHINA

Based on the comprehensive studies of rare-earth elements and strontium and oxygen isotopes from the Baxi gold-skarn deposit in the Songpan-Ganzi orogenic belt, Sichuan,China,which provide in formation on the sources of hydrothermal fluids,their compositional evolution,and the extent and mechanism of mass transfer between fluids and rocks,a deeper understanding has been obtained on the evolution regularity of ore-forming hydrothermal fluids. This study indicates that the ore-forming hydrothermal fluids are metamorphic fluid and meteoric water,and fluid/rock ratios on the order of 0. 02~2. 11 are calculated for an open-system at two stages of hydrothermal mineralization, respectively. A genetic hypothesis has been presented for the skarn which was mainly formed through hydrothermal replacement by metamorphic fluid,which transported from host rock to rockbody.