STRUCTURE AND AGE OF MESOZOIC SEDIMENTARY-VOLCANOGENIC DEPOSITS OF THE PALANA SECTION (WESTERN KAMCHATKA)

Abstract

It is difficult to reconstruct the pre-Cenozoic history of western Kamchatka, because Mesozoic deposits are fragmentarily exposed here. The Palana section, the most complete one among Mesozoic sections of the region, is described and subdivided into volcanogenic and olistostrome sequences. Based on radiolarians, the volcanogenic sequence is attributed to the Campanian-Maastrichtian. The siliceous olistoliths have been formed in the Late Jurassic to Late Cretaceous time. Data on radiolarians indicate the late Campanian-Maastrichtian age of the olistostrome matrix, but volcanogenic olistoliths suggest that the tectonic imbrication and related olistostrome formation took place after the early Maastrichtian. According to published data, the general deformation of the Palana section, which brought about a sharp unconformity at the base of the Anadyrka Formation, has been finished by the mid-Danian.