Title

E.A. SADIKHOV, N.V. SHATOVA (VSEGEI)

U­Pb dating (SHRIMP II) and geodynamic condition of intrusions of the gabbro-­tonalite complexes of the Lok-­Karabakh, Lesser Caucasus (Azerbaijan)

Lok-­Karabakh tectonomagmatic zone is one of major structures in the Lesser Caucasus. It represents a complex fold­block structure composed of en echelon anticlinal and synclinal structures. In plan view, the system forms a northward convex arc 350–400 km long and 30–40 km wide. In the northwest, among the Mesozoic volcanic rocks, pre-­Alpine basement rocks are outcropping. Was studied geochemical and petrographic composition of the next intrusions, Gabahtepe, Novogorevolka, Barum of the gabbro-­tonalite complex and was made the firs isotopic U-­Pb (SHRIMP II) radiometric age. The complex formed in the volcanic island-­arc system in hypabyssal conditions, source rock was oceanic basalts with the next continental contamination. Radiometric age based on dating zircons is 145–157 Ma (oxford­-kimmeridgian).
Keywords: Lesser Caucasus, geochemistry, U­Pb age, Lok­-Karabakh tectonomagmatic zone, gabbro­tonalite, geodynamic.