Title

V. A. Guryanov, A. Yu. Peskov

Ulkan paleorift structure: features of its development and geodynamic setting (south-eastern environs of the Siberian Platform)

A stage of Late Paleoproterozoic within-­plate magmatism as a contrasting series of sedimentary-­volcanogenic rocks, granitoids and basites of the Ulkan volcano-­plutonic complex is clearly recognized in the south­eastern flanking of the Siberian Platform. The formation of these anorogenic rocks in the intraplate settings was associated with mantle plume activity at 1.77–1.70 Ga. The Ulkan paleorift structure has features of a three-­armed geometry indicative of intense rifting due to hotspot activity. Granitoids and volcanics of the Ulkan complex were formed in the intra-­continental setting of stretching accompanied by rising of the mantle plume. The Ulkan alkali-­leucogranite massif was such a hotspot-­type diapir in the Late Paleoproterozoic.
Key words: paleorift, graben, massif, Ulkan volcano-plutonic complex, formation, plume, mantle diapir, hotspot.