The Mongol-Okhotsk Ocean in Mongolia (Hangai-Hentei Basin). Restoring the geodynamic situation of the Late Paleozoic northern active continental margin of the Mongol-Okhotsk Ocean

      Аннотация: The Mongol-Okhotsk Belt extends from the present Sea of Okhotsk in the northeast to Central Mongolia in the southwest and represents a part of the widespread Central Asian Orogenic Belt. The Mongol-Okhotsk suture zone was generated during the Late Paleozoic to Mid Mesozoic by the subduction of the Mongol-Okhotsk Ocean. The remnant permits to study the enigmatic tectonic evolution of the paleo-ocean. A suitable place for analyzing the geodynamic development of the Mongol-Okhotsk Ocean is given by the Hangai-Hentei basin in Mongolia that is regarded as an accretionary wedge terrane located northwest of the suture zone. This research yielded new data from lithostratigaphic and sedimentological investigations as well as provenance analyses on the Silurian to Carboniferous northern active continental margin of the Mongol-Okhotsk Ocean. The work is focused on the Carboniferous trench basin turbidite series of the Gorkhi Formation within the Hangai-Hentei basin. Field work and sample collection in the Hangai-Hentei basin provided new data for defining the type and timing of ocean formation, the subduction and the opposing margins.

Ключевые слова: Sandstone Provenance, Central Asian Orogenic Belt, Mongol-Okhotsk Ocean Mongolia, Accretionary prism, Palaeo-Pacific seamount accretion, detrital zircon, U–Pb geochronology, Hf isotope analyses