贵州半坡锑矿床的方解石C、O同位素地球化学研究

C and O isotopic geochemistry of calcite from Banpo antimony deposit,Guizhou

贵州半坡锑矿床位于扬子地台东南缘,是我国华南锑成矿带"半坡式"锑矿床的代表矿床之一,本文拟通过对该矿床成矿期方解石C、O同位素组成的研究,探讨矿床成矿流体来源及演化.研究发现:方解石的C同位素组成与海相碳酸盐岩相似,O同位素组成位于海相碳酸盐岩与幔源岩浆范围之间,靠近海相碳酸盐岩,且晚期脉状方解石O同为素组成较早期团块状方解石低,显示成矿流体可能受到幔源岩浆的影响,且影响效果随着成矿作用的进行而增大.厘清成矿流体来源为华南"半坡式"锑矿的找矿提供了依据.

The Banpo antimony deposit in Guizhou,located in the southeastern margin of the Yangtze platform,which is the representative deposits of the“Banpo type”antimony deposit in the antimony metallogenic belt of South China.This paper intends to discuss the source and evolution of metallogenic fluid through the study of the C and O isotope composition of calcite in the metallogenic stage.It is found that the C isotope composition of calcite is similar to that of marine carbonate rocks.The O isotope composition is located between marine carbonate rocks and mantle-derived magma,close to marine carbonate rocks,and the composition of late vein calcite is lower than that of early massive calcite,indicating that the metallogenic fluid may be affected by mantle-derived magma,and the effect increases with the progress of mineralization.Clarify the source of ore-forming fluid provides a basis for the prospecting of"Banpo type"antimony deposits in South China.