Potassic volcanics of Central Kamchatka and the Late Cretaceous-Paleogene Kuril-Kamchatka alkaline province

New and published geochemical data on the Late Cretaceous-Paleogene potassi c subalkalic and alkalic volcanic rocks of the Kuril-Kamchatka alkaline pro vince (Little Kurils, Central Kamchatka, Eastern Kamchatka, Belaya River, a nd Southern Koryak Range) were analyzed. In contrast to a widely accepted o pinion on the affiliation of these volcanics with the shoshonite series of the island-are type, the potassic alkalic and subalkalic volcanics of the p rovince are considered as part of the series of lamproite-like rocks. They show high Mg, Cr, and Ni contents, variable concentrations of a number of i ncompatible elements at restricted variations in potassium contents (define d by equilibrium with phlogopite under magmatic or metasomatic conditions), and depletion in Th, U, Zr, and Hf. These characteristics are typical of t he low-titanium varieties of lamproite-series rocks. The lamproite-like roc ks were distinguished into a particular series, which appears in the geodyn amic environment of incipient rifting in an island-are system.