Basic Dikes Characteristics And Its Relationship With Uranium Metallogeny In Huangmeijian,Anhui Province

Luzong Basin is an important part of the metallogenic belt in the middle and lower reaches of the Yangtze River.The Huangmeijian intrusion and its surrounding areas are one of the important volcanic-type uranium metallogenic areas in China.Based on the systematic collection and collation of previous work,comprehensive analysis and field geological survey,the petrology,chronology and rocks of the Huangmeijian basic dike system have been developed.Geochemistry,isotope geochemistry and ore geochemistry have been studied.The basic dike rocks have been determined and the temporal-spatial and genetic relationship between the basic dike rocks and uranium mineralization has been discussed.The achievements and understandings as follows:?1?The study on geochronology indicates that diabase-porphyrite is formed with in107±Ma,the ages of urainium was 108.7±M.?2?The Petrogeochemical characteristics studies have shown that the diabase-p orphyritethe belongs to shoshonite The content of SiO₂ between 51.93%⁵8.87%,a lkaline rich,high K,poor Ti.The rocks enriched in LREE,LILE,and incompatible elements,no Eu depletion,and has similar distribution curves of rare earth elemen ts and trace elements with the oceanic basalt?OIB?.(⁸⁷Sr/⁸⁶Sr)i were in the ranges of 0.70575⁰.70588,?Sr=57.46⁵8.80,(¹⁴³Nd/¹⁴⁴Nd)iand?_Nd?t?were in the ranges of 0.512124⁰.512188 and of-6.1^-7.3 It is concluded that the diabase-porphyrit ethe in Huangmeijian area belongs to shoshonite which originated in enriched mantl e?EMI?.?3?Studies on trace elements in ores and isotopes show that uranium metallogenic materials are mainly derived from enriched mantle or related crust-mantle source areas,and that the metallogenic materials are of mantle or deep origin.?4?The evolution of magmatism in luzong basin were related to extensional environment and upwelling of asthenosphere material after the continental collision between Yangzi block and North China block;The age of shoshonite fundamental restrict a time limit for the lithospheric thinning in Luzong area;It was speculated that dynamic evolution of lithospheric thinning maybe play an important constraint on hydrothermal uranium mineralization.?5?The spatiotemporal relationship between basic dikes and uranium mineralization shows that basic dikes are closely related to uranium deposits in time and genesis,and basic dikes can be used as an important basis for identification and prediction of uranium mineralization vision zone.