Petrogenesis and rubidium enrichment indication of the Fuling rock mass in southern Anhui Province
The Fuling rock mass in southern Anhui Province,located in the eastern section of the Jiangnan uplift zone,is a complex granitic rock mass that has experienced multi-stage evolution.It primarily comprises two lithologies:Monzogranite and K-feldspar gran-ite.By investigating the geological,petrographic,and petrogeochemical characteristics of the Fuling rock mass,this study delved into its evolutionary characteristics,genetic types,and tectonic environment,aiming to clarify its indication significance for rubidium en-richment.The results of this study are as follows:① The geochemical characteristics of the Fuling rock mass demonstrate high SiO2,Na2 O,K2 O,and Al2 O3 contents,high w(K2O)/w(Na2 O)ratios,and aluminum saturation indices(A/CNK)ranging from 0.95～1.08(average:0.99),suggesting high-K calc-alkaline quasi-aluminous to peraluminous granites;② In terms of trace elements,the Fuling rock mass possesses high Li,Rb,Nd,and Ta contents and significantly low Sr and Ba contents,which may be associated with the fractional crystallization of feldspar;③ The w(Nb)/w(Ta)ratios ranging from 5.71～10.94(average:8.41)and Mg#values ran-ging from 0.02～0.31(average:0.13)indicate that the Fuling rock mass was primarily derived from the partial melting of lower crust rocks,suggesting A-type granites in a non-orogenic extensional environment;④ The Rb content in the Fuling rock mass increases with the magmatic evolution degree.Compared to monzogranites,K-feldspar granites with a higher evolution degree display higher Rb con-tent,implying that the Rb content in the Fuling rock mass is generally controlled by magmatic evolution.Overall,this study holds some reference significance for understanding the Yanshanian diagenesis and mineralization of southern Anhui Province.
granitepetrolgenesisgeochemistryrubidiumFuling rock mass
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