The upper mantle of Kamchatka in isotopic-geochemical and geophysical anomalies: The role of asthenospheric diapirism

Data of isotopic-geochemical, seismotomographic, and gravimetric studies of the mantle characteristics of the Kamchatka and Bering Sea regions are compared. It is shown that the revealed isotopicgeochemical anomalies are well verified by the geophysical materials. A hypothesis is put forward that the anomalies of the Central Kamchatka and Bering Sea regions are a consequence of the penetration of local diapirs into the lithosphere; their activity is associated with the appearance of rocks belonging to the intraplate geochemical type. The juncture region of the Kuril-Kamchatka and Komandor-Aleutian island arc systems is characterized by the higher participation of crustal material in the composition of the volcanic rocks of the mantle genesis and by a combination of manifestations of the island arc and intraplate types.