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The Tuwaishan, Baoban, Erjia, Bumo and other gold deposits in western Hainan occur in Precambrian metamorphic clastic rocks and are structurally controlled by the Gezhen shear zone. Fluid inclusion studies have been carried out of the gold deposits mentioned above. The homogenization temperatures of the whole fluid inclusion population range from rrrrrrrrn140℃ to 370℃, indicating that gold was precipitated mainly at 240-250℃. The salinities are within the range of 2.0-9.2 wt% NaCl equiv. and the pressure of formation of the deposits was estimated at about 270×105-500×105Pa, corresponding to a depth of about 1.1-2.0 km under lithostatic confinement. Chemical studies show that the ore fluid is of the Na+(K+)-Ca2+-Cl-(F-) type. The δ18O and δD values of the fluid vary from -2.7‰- +4.4‰ and -50‰-87‰. Evidence developed from fluid inclusions and geological setting indicates that the ore fluid was a mixture of mag-matic and meteoric-hydrothermal waters. Changes in chemical composition and δ18O and δD of
The Tuwaishan, Baoban, Erjia, Bumo and other gold deposits in western Hainan occur in Precambrian metamorphic clastic rocks and are structurally controlled by the Gezhen shear zone. Fluid inclusion studies have been carried out of the gold deposits mentioned above. The homogenization temperatures of the The whole fluid inclusion population range from r r r r r r r n 140 ° C to 370 ° C, indicating that the gold was precipitated mainly at 240-250 ° C. The salinities are within the range of 2.0- 9.2 wt% NaCl equiv. And the pressure of formation of the deposits was estimated at about 270 x 105-500 x 105 Pa, corresponding to a depth of about 1.1-2.0 km under lithostatic confinement. Chemical studies show that the ore fluid is of the The δ18O and δD values of the fluid vary from -2.7 ‰ - + 4.4 ‰ and -50 ‰ -87 ‰. Evidence developed from fluid inclusions and geological settings indicates that the ore fluid was a mixture of mag-matic and meteoric-hydrothermal waters. Changes in chemical composition and δ18O and δD of