长江中下游铜、金矿床成矿流体系统的形成条件及机理

Forming Conditions and Mechanism for the Fluid Ore-forming System of the Copper,Gold Deposits in the Middle and Lower Reaches of the Yangtze River Area

长江中下游铜、金成矿带是我国最重要的金属成矿带之一。成矿流体系统形成的地球动力学背景及地质地球化学条件对比研究表明 ,赋存于石炭系中的层状铜、金矿床是海西期拉张背景下热卤水沿同生断裂经喷流作用形成的海底喷流 (热水 )沉积矿床 ;与燕山期中酸性侵入岩有关的铜、金矿床是在上地幔隆起、张性或向张性过渡背景下形成的 ,是中酸性岩浆经熔体 流体分离作用形成的岩浆热液与大气降水混合 ,经水 岩作用等复杂的输运和化学反应耦合过程的动力学产物。

There are two series of Cu,Au deposits,the stratiformed deposits and the intrusi ve\|related ones in the mineralization belt of the middle and lower reaches of t he Yangtze River area.Comparative studies on forming geodynamic backgrounds,geol ogical and geochemical conditions of the ore\|forming systems have been undertak e n in this paper.The stratiformed deposits were formed in Hercynian period by sub marine exhalation\|sedimentation (SEDEX) of hot brine through the synchronous ba sement faults in a tensional environmental,and the intrusive\|related deposits w ere formed in Yenshanian in a tensional or a transitional period to tensional en vironment during the upper mantle doming by water\|rock interaction and complex transport\|chemical reaction dynamic processes,the ore\|forming fluids were main ly magmatic water from melt\|fluid partition and some meteoric water.