Chalcopyrite Intergrowths in sphalerite in the Meixian Lead—Zine Deposit,Fujian Province and their Metallogenic Significance

Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains,intergrown chalcopyrite also occurs as rods,myrmekites and lamellae aligned along cleavages and twin boundaries of the host sphalerite.The majority of the intergrowths could have been formed by replacement of sphalerite by chalcopyrite,albeit part of them may have resulted from exsolution,Not only copper,but also iron were introduced into the sphalerite by replacive fluids.While the front of the replacing fluid was moving forward through a sulphide orebody,Zn and Pb were dissolved and Cu was precipitated,resulting in zonal refining of the sulphide ores,The remobilized zinc and lead were precipitated at favourable sites with changed physico-chemical conditions .This is a possible mechanism for the formation of copper-poor zinc and lead ores above or lateral to the copper orebodies in some of the massive sulphide deposits reworked and overprinted by late-stage granites and their hydrothermal fluids.

Chalcopyrite intergrowths in sphalerite in the Meixian lead-zinc deposit, Fujian Province and their metallogenic significance

Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as rods, myrmekites and lamellae aligned along cleavages and twin boundaries of the host sphalerite. The majority of the intergrowths could have been formed by replacement of sphalerite by chalcopyrite, albeit part of them may have resulted from exsolution. Not only copper, but also iron were introduced into the sphalerite by replacive fluids. While the front of the replacing fluid was moving forward through a sulphide orebody, Zn and Pb were dissolved and Cu was precipitated, resulting in zonal refining of the sulphide ores. The remobilized zinc and lead were precipitated at favourable sites with changed physico-chemical conditions. This is a possible mechanism for the formation of copper-poor zinc and lead ores above or lateral to the copper orebodies in some of the massive sulphide deposits reworked and overprinted by late-stage granites and their hydrothermal fluids. This project was supported by the National Natural Science Foundation of China (No. 49733120).