摘要
Multi-constraints are used in this paper to discuss the ΣCO<sub>2</sub> source in oreforming hydrothermal solution of granite-type uranium deposit in South China. The studies show that highly acidic and uraniferous granitic magma cannot produce the fluid rich in ΣCO<sub>2</sub>. Controlled by three periods of crust extension and corresponding to three major periods of U-mineralization in South China respectively, the ΣCO<sub>2</sub> in each ore-forming hydrothermal solutions is all mantle-derived. Our studies reasonably explain why the mineralization did not occur immediately after the end of differentiation of the granitic magma rich in uranium, and why the ore-forming time of granite-type uranium deposit focuses on the time of crust extension after the formation of the uraniferous granites.
Multi-constraints are used in this paper to discuss the ΣCO_2 source in oreforming hydrothermal solution of granite-type uranium deposit in South China. The studies show that highly acidic and uraniferous granitic magma cannot produce the fluid rich in ΣCO_2. Controlled by three periods of crust extension and corresponding to three major periods of U-mineralization in South China respectively, the ΣCO_2 in each ore-forming hydrothermal solutions is all mantle-derived. Our studies reasonably explain why the mineralization did not occur immediately after the end of differentiation of the granitic magma rich in uranium, and why the ore-forming time of granite-type uranium deposit focuses on the time of crust extension after the formation of the uraniferous granites.
基金
Project supported by the National Natural Science Foundation of China, and by the Fund of Laboratory of Ore Deposit Geochemistry, Academia Sinica.
