Eclogite trace in evolution of Late Cenozoic alkaline basalt volcanism on the southwestern flank of the Baikal Rift Zone: Geochemical features and geodynamic consequences
- Authors: Perepelov A.B.1, Kuzmin M.I.1, Tsypukova S.S.1, Demonterova E.I.2, Ivanov A.V.2, Shcherbakov Y.D.1, Puzankov M.Y.3, Odgerel D.4, Bat-Ulzii D.5
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Affiliations:
- Vinogradov Institute of Geochemistry, Siberian Branch
- Institute of the Earth’s Crust, Siberian Branch
- Institute of Volcanology and Seismology, Far East Branch
- Institute of Paleontology and Geology
- Mongolian University of Science and Technology
- Issue: Vol 476, No 2 (2017)
- Pages: 1187-1192
- Section: Geochemistry
- URL: https://journals.rcsi.science/1028-334X/article/view/191098
- DOI: https://doi.org/10.1134/S1028334X1710018X
- ID: 191098
Cite item
Abstract
Eclogitized material from the oceanic lithosphere are the most likely source of alkaline basalt magmas in the formation of Late Cenozoic volcanic areas on the southwestern flank of the Baikal Rift Zone. Basaltic trachyandesites of the early stage of volcanism (Pg32 ~ 28–23 Ma) are rich in high field strength elements (HFSE), P2O5, F, Zn, Ga, Sr, Sn, and light rare earth elements (LREE); they are characterized by high values of the following ratios: Fe/Mn = 72–77, Sm/Yb = 7.7–8.5, Sr/Y = 57–63, and Ga/Sc = 2.1–2.3. At this stage, magmas are formed under conditions with a 2–8% degree of partial melting of the mantle substrate enriched with the material of the eclogite source (50–70%) (Cpx/Grt = 1.5–1.7). Basaltoid magmas of the final stage of volcanism (N13–N21 ~ 6–4 Ma) are formed from melting (1.5–4%) of a less fertilized mantle (Cpx/Grt = 2.1–3.1, Fe/Mn = 62–71, Sm/Yb = 3.5–4.6, Sr/Y = 29–44, Ga/Sc = 1.0–1.4). The directed variations of the compositions of the successive basaltoid magmas, which were formed in the Late Cenozoic, create an “eclogite trace” in this area.
About the authors
A. B. Perepelov
Vinogradov Institute of Geochemistry, Siberian Branch
Author for correspondence.
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 650033
M. I. Kuzmin
Vinogradov Institute of Geochemistry, Siberian Branch
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 650033
S. S. Tsypukova
Vinogradov Institute of Geochemistry, Siberian Branch
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 650033
E. I. Demonterova
Institute of the Earth’s Crust, Siberian Branch
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 664033
A. V. Ivanov
Institute of the Earth’s Crust, Siberian Branch
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 664033
Yu. D. Shcherbakov
Vinogradov Institute of Geochemistry, Siberian Branch
Email: alperdig@irk.ru
Russian Federation, Irkutsk, 650033
M. Yu. Puzankov
Institute of Volcanology and Seismology, Far East Branch
Email: alperdig@irk.ru
Russian Federation, Petropavlovsk-Kamchatsky, 683006
D. Odgerel
Institute of Paleontology and Geology
Email: alperdig@irk.ru
Mongolia, Ulan-Bator
D. Bat-Ulzii
Mongolian University of Science and Technology
Email: alperdig@irk.ru
Mongolia, Ulan-Bator