He and Ar Isotopic Components of Main Tin Deposits from Central Nanling Region and Its Signification
He and Ar isotopic components of the fluid inclusions in pyrites from the main tin deposits in the central Nanling region are studied to discuss the genesis and material sources of these deposits. The results indicate that the 40Ar/36Ar ratio varies between 288 and 371 and 3 He/4 He 0. 09~28. 58 Ra. He and Ar concentrations change greatly in different area while 40Ar/36Ar and 3He/4He ratios are more consistent in the same area. 40Ar/36Ar ratios are between that of the atmosphere saturation water(including meteoric precipitation and seawater) (40 Ar/36 Ar≈295. 5)and that of Hawaii hotspot (40Ar/36Ar = 350~360);Their 3He/4 He ratios are apparently above those of the continental crust (3 He/4 He≈ 0. 03Ra) and are within the range of the averaged crust, of the primitive mantle(3 He/4 He≈8. 57 Ra) and of the characteristic Hawaii hotspot (3He/4 He≈27. 14 Ra). Above features indicate that the metal-logenic fluids are related to the activation of the mantle plume, and they probably are the mixing product of the mantle-and crust-derived fluids and of the meteoric water. The results provide new evidences that the tin deposits are product of the crust-mantle interaction and that the mantle plumes had existed in the Nanling region.
He,Ar isotopefluid inclusionstin depositcentral Nanling region
NETL
NSTL
万方数据
维普
