Abstract
Framing of the Archaean greenstone belts of the Kursk Block (KB) of the East Sarmatia preserves rocks of the TTG association: those do not form massifs with distinct boundaries, but occur as fields gradually transiting into gneisses and migmatites. According to Sm–Nd isotope–geochemical data, the TTG are characterized by positive values of eNd(2960) = +0.3…+1.6 and protolith model ages of ТNd(DM) = 3100–3200 Ma. Magmatic protoliths of the Kursk Block TTG were formed about 2960 Ma by melting from a juvenile basite source. These age estimates are significantly younger than heterochronous (3.19, 3.13 and 3.07 Ga) TTGs of the Middle Dnieper granite–greenstone terrane. On the other hand, the similarity of eNd(T) implies a single source of their protoliths. Consequently, the KB TTGs, apparently, are a result of transformation of an older sial crust preserved within the Middle Dnieper Block.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
