Mn. Zakharov et al., Hydromagmatophile and rare earth elements in the Cretaceous-Paleogene basaltoids of the Verkhnyaya Kolyma megadome, GEOCHEM INT, 38, 2000, pp. S28-S38
The chemical composition of the Cretaceous-Paleogene bimodal trachyrhyolite
-basaltic association has been studied in the southwestern portion of the V
erkhnyaya Kolyma megadome. The first data have been presented on the concen
trations of REE, Nb, and other elements in the subalkaline basaltoids of th
e Magadan region. The higher P, Ti, and Zr contents in these rocks as compa
red to andesite rock associations of the Okhotsk-Chukotka volcanogenic belt
indicate a deep mantle origin of the parental alkaline picrite melts. Stro
ntium isotopic data suggest that acid volcanics of the studied bimodal asso
ciation were derived through crustal melting under the action of basaltic m
agma heat.