Yang Zhong-fang

Rock-Forming and Ore-Forming Temperatures of Lianhuashan Tungsten Deposit,Guangdong Province

The Lianhuashan tungsten deposit occurs in the volcanic terrain in the coastal area of Southeast China, where rhyolite, quartz porphyry and granite constitute a complete magmatic series. The orebodies are located in the endo- and exo-contacts between the quartz porphyry and the metasandstone of the Xiaoping coal measures. Homogenization temperatures of melt inclusions in zircon and quartz are 1100°C and 1050°C for rhyolite, 1000°C and 860°C for quartz porphyry, and 950 – 1000°C and 820°C for granite, respectively, demonstrating that the rockforming temperatures dropped successively from the eruptive to the intrusive rocks and that the homogenization temperatures of melt inclusions in zircon are 50 – 180°C higher than those in quartz. Homogenization temperatures of gas liquid inclusions in quartz are 230 – 520°C (mostly 230 – 270°C) for quartz porphyry, 200 – 450°C (mostly 200 – 360°C) for ore-bearing quartz veins, 150– 210°C for granite and 170 – 200°C for the vein quartz in it. Quartz from the quartz porphyry and from the ore-bearing quartz veins show similar characteristics in inclusion type and homogenization temperature, indicating that intergranular solutions must have been formed upon cooling of magma and that ore-forming solutions for the tungsten mineralization were evolved mainly from ore-bearing intergranular solutions in the quartz porphyry.