Abstract:
In East Kamchatka, Cretaceous oceanic rocks are known on the Cape Kamchatskiy peninsula and in the melange zones of the East Ranges. The authors' investigations in 1985-1987 revealed oceanic rocks in the eastern part of the Kumroch Range as well. The previously-identified Veltovaya Formation of this region, consisting of basalts and cherty, carbonaceous and clastic rocks, was thought to be a single stratigraphic section dated as Late Cretaceous to Miocene. Two rock complexes of different compositions (cherty-clastic and cherty-basaltic) and exhibiting tectonic relationships can be identified in the Vetlovaya Formation. In the eastern Kumroch Range there are oceanic rocks that constitute tectonic slabs in similar-age rocks of the ocean-side slope of the island arc. This phenomenon is best explained by accretion of oceanic blocks in middle Paleogene time.