TY - JOUR

T1 - The Kataevo Island Arc System of the Paleoasian Ocean (Transbaikalia): Composition, Age, Paleomagnetism, and Formation Geodynamic Settings

AU - Gordienko, I. V.

AU - Metelkin, D. V.

AU - Lantseva, V. S.

AU - Elbaev, A. L.

N1 - We are sincerely grateful to corresponding member of the RAS A.N. Didenko and Dr. A.B. Perepelov for useful remarks and comments concerning this paper. This study was financially supported by the Earth Sciences Division of the Russian Academy of Sciences, Section of fundamental and exploration research: program 1.5.2.3. “Structure and formation history of global and regional tectonic structures” in the budget assignment of the Laboratory of geodynamics of the Dobretsov Geological Institute (Project No. АААА-А21-121011890029-4). This study was supported by grants from the Russian Foundation for Basic Research and the Russian Science Foundation (Nos. 19-05-00312, 21-17-00052, and 22-27-20141).

PY - 2023/3

Y1 - 2023/3

N2 - Based on new data on the geology, composition, U–Pb isotopic age, and paleomagnetism of the metavolcanic rocks of the Kataevo Formation, we consider the geodynamic conditions of their formation and alteration. The Kataevo Formation metavolcanic rocks belong to the K–Na-high-alumina andesite–andesibasalt–basalt volcanic series. Results for U–Pb analysis of magmatic zircon (SHRIMP II, 8 spots) from a metaandesibasalt sample of the stratotype section on Ungo River yielded and age of 852 ± 9 Ma. Isotope systems for Sm– Nd yield a positive εNd(852) = +9.29, which indicates a juvenile magmatic source, close to depleted mantle (DM), with a Neoproterozoic protolith TNd(DM) model age. The content of the less mobile HFSE and REE (ppm) is consistently low for Nb (8–15), Ti (7074–12,410), Ta (0.32–0.93), Eu (1.80–2.29), Се (50–79), Y (21–25), Yb (2.1–2.8), Rb (10–24) and elevated for Sr (1000–1500), Zr (170–270), La (25–41), and Ba (600–800). All studied parameters place the metavolcanic rocks close to the contemporary Kurile–Kamchatka type of developed island arcs. Paleomagnetic analysis of the section of metavolcanic rocks shows a complete remagnetization ca. 120 Ma. This is synchronous with manifestations of intraplate basaltoid magmatism in the studied region, the most typical example of which is the Lower Cretaceous Khilok Formation.

AB - Based on new data on the geology, composition, U–Pb isotopic age, and paleomagnetism of the metavolcanic rocks of the Kataevo Formation, we consider the geodynamic conditions of their formation and alteration. The Kataevo Formation metavolcanic rocks belong to the K–Na-high-alumina andesite–andesibasalt–basalt volcanic series. Results for U–Pb analysis of magmatic zircon (SHRIMP II, 8 spots) from a metaandesibasalt sample of the stratotype section on Ungo River yielded and age of 852 ± 9 Ma. Isotope systems for Sm– Nd yield a positive εNd(852) = +9.29, which indicates a juvenile magmatic source, close to depleted mantle (DM), with a Neoproterozoic protolith TNd(DM) model age. The content of the less mobile HFSE and REE (ppm) is consistently low for Nb (8–15), Ti (7074–12,410), Ta (0.32–0.93), Eu (1.80–2.29), Се (50–79), Y (21–25), Yb (2.1–2.8), Rb (10–24) and elevated for Sr (1000–1500), Zr (170–270), La (25–41), and Ba (600–800). All studied parameters place the metavolcanic rocks close to the contemporary Kurile–Kamchatka type of developed island arcs. Paleomagnetic analysis of the section of metavolcanic rocks shows a complete remagnetization ca. 120 Ma. This is synchronous with manifestations of intraplate basaltoid magmatism in the studied region, the most typical example of which is the Lower Cretaceous Khilok Formation.

KW - Kataevo volcanic arc

KW - Neoproterozoic

KW - Paleoasian Ocean

KW - Siberian paleocontinent

KW - U–Pb age

KW - geochemistry

KW - paleomagnetism

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85149037489&origin=inward&txGid=3c0877d0ee05ec6af24a8ca3b90a47f9

UR - https://www.mendeley.com/catalogue/6629e981-497a-3093-99b5-65864a882fe6/

U2 - 10.2113/RGG20224519

DO - 10.2113/RGG20224519

M3 - Article

VL - 64

SP - 319

EP - 333

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 3

ER -