Generation of lower-middle Jurassic trondhjemite series in the Lesser Caucasus (Republics of Armenia and Mountainous Karabakh)

The age and geotectonic history of trondhjemite (plagiogranite) magmatism of Mesozoic is especially important for unraveling the geological/geodynamic evolution of the east-southeastern segment of the Lesser Caucasus (LC). Issues for a more definite and comprehensive interpretation of tectonic implications of the LC ophiolites with adjacent Somkheto–Karabagh and Spitak–Kapan Jurassic–Cretaceous zones have been discussed anew. Evidently, these zones, particularly the geological units in them, are strongly associated with each other both spatially and temporally. U–Pb zircon dating of plagiogranites from Sevan ophiolite (central part of Amasia–Sevan–Hakari ASH suture zone) and from mentioned zones in LC provides more reliable geochronological constraints on the evolution of Neotethys (?). Obviously, all zircon ages are in the interval of late Early to late Middle Jurassic epoch (~180–165 Ma)