幔源铀成矿作用探讨

Discussion on Mantle-derived Uranium Mineralization

地幔流体及深源铀成矿作用是当前铀矿地学界备受关注的前沿课题。文章扼要阐述了幔源铀成矿的地球动力学背景,评述了热点铀成矿理论。通过地幔流体参与铀成矿的现实性与地幔含铀性的论证,结合粤北"交点型"铀成矿地质地球化学特征,认为地幔中铀含量存在不均一性,在大陆型热点活动(地幔柱)区的岩石圈地幔通常含有较高的铀丰度;提出在热点驱动下,地幔流体(如CO2、F等)能够溶解或萃取地幔岩中的铀并得以浓集形成富铀成矿流体,幔源铀成矿是可能的。对幔源铀成矿作用机理作了初步探讨。

Studies of mantle-derived fluids and deep-sourced uranium mineralization have become one of the most interesting researches for uranium geoscientists in the world. The geodynamic regime of mantle-derived uranium metallogenesis and theory of hotspot uranium metallogenesis are briefly discussed. Through analysis on mantle-derived fluids attached to uranium minerlization and content of uranium in mantle, combining with geological—geochemical characteristics of ＂intersection-type＂ uranium ore-deposits in north Guangdong, it is showed that the content of uranium in mantle was inhomogeneity , lithospheric mantle relation to continental-type hotspot generally contained higher uranium abundance, and concluded that, within the activity of hotspot, mantle fluids（e.g CO2,F） were capable of dissolving or extracting uranium contained in mantle rocks to form mineralization fluid,mantle-derived uranium to form ore-deposit may be actualized. Mechanism of mantle-derived uranium metallogenesis was also discussed.