Extensive charnockitic-granitic magmatism in the crystalline crust of West Lithuania

A number of plutons of charnockitic and granitic rocks have been revealed in the West Lithuanian Granulite Domain in the course of the recent geological mapping. The largest, Kur iai (Curonian), batholith has been identified by gravity and magnetic anomalies and drill cores of 86 wells. Intrusions are composed of rocks of intermediate to felsic composition systematically attributed to charnockite, enderbite, mangerite, opdalite and granite. Rocks, characterized by 53 new ICP-MS and ES analyses, combine geochemical patterns characteristic both of A and S type granites being predominantly ferroan, alkali-calcic and calc-alkaline, high potassic to shoshonitic, but at the same time mainly peraluminous. Four U-Pb ID-TIMS zircon dates suggest formation of a charnockitic-granitic suite at around 1.85-1.82 Ga, presumably in the transitional period from the late orogenic to cratonic stages of formation of the continental crust.