The Early Cambrian Age and Crustal Sources of Granitoids of the Goryachinskiy Pluton (Northern Baikal): Geodynamic Implications

Abstract

New results of U–Pb zircon and Nd–isotope analyses of the Goryachinskiy Pluton adakite granites have been obtained. The pluton is exposed along the Baikal coast in the section where a section of sheared tectonic sheets of the Baikal–Muya Belt wedges out. The determined Early Cambrian (545 ± 6 Ma) age of the granitoids is unusual in the Northern Baikal region. These new geological and isotopic data are interpreted as an indication of the formation of the granitoids studied at the final stage of the Late Baikal strike–slip tectonics, which caused the pulse of the adakite magmatism within the Baikal–Muya belt.