贵州赫章天桥铅锌矿床围岩的氧、碳同位素研究

Oxygen and Carbon Isotop in Guizhou Tianqiao Pb-Zn Deposit

据远矿围岩和近矿蚀变围岩的δ18O和δ13 C ,计算了岩石形成时的介质温度、盐度 ,为讨论不同岩石的形成环境提供了有力的佐证。研究表明 ,远矿围岩的成因类型为准同生白云岩 ,近矿蚀变围岩的白云石化是原岩孔隙中的超咸水与较低盐度成矿溶液混合形成的。二种岩石的形成 ,既有正常沉积来源 ,亦有深源富12 C的CO2 、CH4流体混入。

The salinity and temperature of medium in rock formation are calculated by δ 18 O and δ 13 C of alteration rocks and unalteration rocks,which provides reliable evidence for discussing the formation environment of different rocks.Researches show that the formation cause of unalteration rock is of quasisyngenesis dolomitite type,while the dolmitization of alteration rock is caused by the mixture of lower salt mineralized fluid and supersaline water in the small opening of unalteration rock.The formation of the two kinds of rock involves both normal deposition and infiltration of the fluids rich in 12 C of deep focus CO 2 and CH 4.