The Age and Petrogenesis of Felsic Volcanics of the Algan Mountains, Koryak Highland, Northeast Russia

Autor: A. V. Moiseev, P. I. Fedorov, E. S. Bogomolov, S. A. Palandzhyan, I. V. Gul’pa
Rok vydání: 2021
Předmět:
Zdroj: Russian Journal of Pacific Geology. 15:85-101
ISSN: 1819-7159
1819-7140
Popis: U–Pb zircon dating of felsic volcanic rocks from the Konachan Complex (Algan Mountains, northwestern Koryak Highland) confirmed their Late Miocene age (34.6 ± 0.5–38.8 ± 0.4 Ma, Priabonian). It is shown that these rocks are represented by moderate-potassium peraluminous (ASI = 1.23–1.30), moderate- and high-Mg varieties, frequently with high Cr and Ni contents. The Sr, Y, and Yb contents are similar to those of adakites. The high 143Nd/144Nd and low 87Sr/86Sr ratios in the rocks of the complex in combination with their trace and rare-earth distribution patterns suggest that metabasites weakly contaminated by sedimentary material were one source of silicic melt. The magmatic rocks of the Konachan Complex were formed during accretion of the terranes of the Olyutorka–Eastern Kamchatka island-arc system; the compression locked the upwelling front of continental asthenosphere, thus initiating crustal anatexis and silicic magmatism.
Databáze: OpenAIRE
Externí odkaz: