First geochronological data on felsic lavas from the Ezop-Yamalin volcanoplutonic zone, Khingan-Okhotsk volcanogenic belt

Abstract

The Khingan–Okhotsk volcanogenic belt [3, 7, 10,and others], which includes a series of NE-trending vol-canic zones, has been studied by several researchers [4–7, 9–11, and others] because of the presence of veryhigh-grade tin ore deposits. However, the age and com-position of the host rocks and their geodynamic settingstill remain debatable.According to literature data [3–8, 10, 11, and oth-ers], the belt is subdivided into the Khingan–Olonoi,Ezop–Yamalin, Komsomol’sk, Badzhal, and otherzones (Fig. 1), including several volcanic fields on thecoast of the Tugur and Ul’ban bays, which are under-lain by complexes of three regional structures of differ-ent ages: the Mongol–Okhotsk orogenic belt, Badzhalterrane, and Bureya–Jiamusi superterrane [8]. Applica-tion of precise methods yielded new geochemical andage data on the magmatic complexes of the Khingan–Olonoi, Komsomol’sk, and Badzhal zones [4–6, 10, 11,and others], whereas only scanty data are available onthe composition and age of the Ezop–Yamalin zone.Previous works were devoted to study of the composi-tion of felsic rocks of the zone [6] and the dating of thecomagmatic granitoids [1].In the present paper, we attempted to determine theage of lavas in the Ezop–Yamalin zone that includes theEzop and Yamalin volcanic structures with a total areaof 5000 km