New data on the volcanism of the Central Chukotka segment of Okhotsk-Chukotka volcanogenic belt

The article presents new geochronological and geochemical data on the age and composition of the undifferentiated Cretaceous volcanics of the basin of the Palyavaam river Central Chukotka region. These data indicate the heterogeneity of the rocks of etchikun suites, which are divided into two groups. The andesites of the first group (actually etchikun suites ) are of early Cretaceous age and represent a magmatic phase preceding the formation of the Okhotsk-Chukotka volcanogenic belt (OCHVB). The andesites of the second group correlate well in age and composition to the volcanic rocks of OCHVB. They lie at the base section of Chaunskaya series of OCHVB and indicate gomodromos the evolution of volcanism in the Central-Chukchi sector OCHVB.