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The Rushan gold deposit, explored in recent years in the Jiaodong area, Shandong Province is a quartz vein-type gold deposit hosted in granite. The temperature of its major mineralization episode is between 220℃ and 280℃. The salinity of the ore-forming fluid is 5 % to 9% NaCl equivalent, with H2O and CO2 as the dominant gas constituents. The fluid is rich in Na+, Ca+ and Cl-, but relatively impoverished in K+ and F-, characterized by either Ca2+ >Na+ >K+ (in three samples) or Na+ > Ca2+ > K+ (in six samples). Hydrogen and oxygen isotopes in the ore-forming fluid are highly variable with δ18 OH2O ranging between -7. 70‰ and 5. 97‰ and δDH2O between - 128‰ and - 71‰. The possibility of lamprophyre serving as the source of gold can be excluded in view of its low gold content on the order of 2. 5 × 10 -9. Rb-Sr isochron ages of the deposit and the host Kunyushan granite are (104. 8±1. 5) Ma and 134. 6 Ma respectively with the respective initial Sr ratios of 0. 71307 and 0. 7096. It is considered that the emplacement of the lamprophyre under a tensile environment had provided sufficient heat energy to facilitate deep circulation of meteoric water by which ore metals were extracted from the Kunyushan granite through long-term water-rock reaction.
The Rushan gold deposit, explored in recent years in the Jiaodong area, Shandong Province is a quartz vein-type gold deposit hosted in granite. The temperature of its major mineralization episode is between 220 ° C. and 280 ° C. The salinity of the ore-forming The fluid is rich in Na +, Ca + and Cl-, but relatively impoverished in K + and F-, characterized by either Ca2 +> Na +> K + ( in three samples or Na +> Ca2 +> K + in six samples. Hydrogen and oxygen isotopes in the ore-forming fluid are highly variable with δ18 OH2O ranging between -7. 70 ‰ and 5. 97 ‰ and δDH2O between - 128 ‰ and - 71 ‰. The possibility of lamprophyre serving as the source of gold can be excluded in view of its low gold content on the order of 2. 5 × 10 -9. Rb-Sr isochron ages of the deposit and the host Kunyushan granite are (104. 8 ± 1. 5) Ma and 134. 6 Ma respectively with the respective initial Sr ratios of 0. 71307 and 0. It is considered that the emplacement of the lamprophyre under a tensile environment had provided sufficient heat energy to facilitate deep circulation of meteoric water by which ore metals were extracted from the Kunyushan granite through long-term water-rock reaction.