TY - JOUR

T1 - Traces of intra-oceanic arcs recorded in sandstones of eastern Kazakhstan: implications from U–Pb detrital zircon ages, geochemistry, and Nd–Hf isotopes

AU - Safonova, Inna

AU - Perfilova, Alina

AU - Obut, Olga

AU - Kotler, Pavel

AU - Aoki, Shogo

AU - Komiya, Tsuyoshi

AU - Wang, Bo

AU - Sun, Min

N1 - Funding Information: The authors would like to thank the reviewers, Drs. T. Zhou and J. Yin, for their efforts and advices. The study was supported by the Russian Science Foundation (project # 20-77-10051; isotope studies), Ministry of Science and Education of Russia (project #FSUS-2020-0039; petrographic studies), Russian Foundation for Basic Research (project # 20-35-90091; geochemical studies). Additional support came from the Ministry of Science and Education of Kazakhstan (project # AP08855920), Hong Kong Research Grants Council (HKU17302317), National Nature Science Foundation of China (projects # 41772225, 42011530146), SAFEA: OEI under "Belt and Road Initiative" (project # DL2017NJDX020). Contribution to IGCp#662. Publisher Copyright: © 2021, Geologische Vereinigung e.V. (GV). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2022/11

Y1 - 2022/11

N2 - This paper presents first U–Pb detrital zircon ages, major and trace element geochemical data and whole-rock Nd and Hf-in-zircon isotope data from sandstones of the Char and Zharma zones of eastern Kazakhstan. Petrographically the sandstones represent greywackes. The U–Pb ages of detrital zircons show unimodal distributions peaked at 345–340 and 330–325 Ma indicating post-Early Carboniferous deposition. The sandstones have high CIA values (60–68), suggesting moderate to weak chemical weathering. Their high ICV values (1.1–1.3) and relatively high MgO and low Y, Nb indicate an immature probably mafic–intermediate igneous source (low La/Th, medium Hf). Positive whole-rock εNd(t) and zircon εHf(t) indicate dominantly juvenile character of igneous rocks in the provenance. In total, the unimodal character of U–Pb detrital zircon age patterns, the chemical composition of sandstones similar to that of associated volcanic rocks and the positive values of εNd(t) and εHf(t) suggest their derivation from one or more intra-oceanic arcs. The data from eastern Kazakhstan fit those obtained from late Paleozoic greywacke sandstones of NW China. The new geochemical and geochronological data from sandstones and published data from oceanic and supra-subduction ophiolites of eastern Kazakhstan suggest an extended Pacific-type subduction system in the western Paleo-Asian Ocean in Devonian–early Carboniferous time.

AB - This paper presents first U–Pb detrital zircon ages, major and trace element geochemical data and whole-rock Nd and Hf-in-zircon isotope data from sandstones of the Char and Zharma zones of eastern Kazakhstan. Petrographically the sandstones represent greywackes. The U–Pb ages of detrital zircons show unimodal distributions peaked at 345–340 and 330–325 Ma indicating post-Early Carboniferous deposition. The sandstones have high CIA values (60–68), suggesting moderate to weak chemical weathering. Their high ICV values (1.1–1.3) and relatively high MgO and low Y, Nb indicate an immature probably mafic–intermediate igneous source (low La/Th, medium Hf). Positive whole-rock εNd(t) and zircon εHf(t) indicate dominantly juvenile character of igneous rocks in the provenance. In total, the unimodal character of U–Pb detrital zircon age patterns, the chemical composition of sandstones similar to that of associated volcanic rocks and the positive values of εNd(t) and εHf(t) suggest their derivation from one or more intra-oceanic arcs. The data from eastern Kazakhstan fit those obtained from late Paleozoic greywacke sandstones of NW China. The new geochemical and geochronological data from sandstones and published data from oceanic and supra-subduction ophiolites of eastern Kazakhstan suggest an extended Pacific-type subduction system in the western Paleo-Asian Ocean in Devonian–early Carboniferous time.

KW - Arc-derived sediments

KW - Central-Asian orogenic belt

KW - Char zone

KW - Paleo-Asian Ocean

KW - U–Pb zircon geochronology

KW - Zharma zone

UR - http://www.scopus.com/inward/record.url?scp=85108327229&partnerID=8YFLogxK

U2 - 10.1007/s00531-021-02059-z

DO - 10.1007/s00531-021-02059-z

M3 - Article

AN - SCOPUS:85108327229

VL - 111

SP - 2449

EP - 2468

JO - International Journal of Earth Sciences

JF - International Journal of Earth Sciences

SN - 1437-3254

IS - 8

ER -