The Itmurundy Accretionary Complex, Northern Balkhash Area: Geological Structure, Stratigraphy and Tectonic Origin
- Authors: Safonova I.Y.1,2, Perfilova A.A.1,2, Obut O.T.1,3, Savinsky I.A.1,2, Chyornyi R.I.1,2, Petrenko N.A.1,2, Gurova A.V.1,2, Kotler P.D.1,2, Khromykh S.V.1,2, Krivonogov S.K.1,2, Maruyama S.1,4
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Affiliations:
- Novosibirsk State University
- Sobolev Institute of Geology and Mineralogy, SB RAS
- Trofimuk Institute of Petroleum Geology and Geophysics SB RAS
- Tokyo Institute of Technology
- Issue: Vol 13, No 3 (2019)
- Pages: 283-296
- Section: Article
- URL: https://journals.rcsi.science/1819-7140/article/view/211641
- DOI: https://doi.org/10.1134/S1819714019030072
- ID: 211641
Cite item
Abstract
The Itmurundy zone of the northern Balkhash area is a Pacific-type orogenic belt. It possesses a complex geological structure and hosts rocks of mantle, accretionary and post-orogenic associations. The volcanic and sedimentary rocks of the accretionary association belong to three suites: Itmurundy (O1-2), Kazyk (O2-3) and Tyuretai (O3-S1). The suites are separated by tectonic unconformities or faults of three orders: 1) large regional faults; 2) medium faults separating mantle and oceanic accreted rocks; 3) small faults separating packages consisting of oceanic sediments. The Itmurundy Fm. (O1-2) is the most lithologically variable consisting of oceanic basalt, pelagic chert, hemipelagic siliceous mudstone and siltstone, and trench greywacke sandstone. The packages, each consisting of chert-siliceous mudstone, are separated from each other by 2nd and 3rd order faults of probably thrust nature, i.e. they are parts of duplex structures. The presence of duplex structures and the high degree of deformation of Itmurundy Fm. rocks are typical of accretionary complexes. The associations of volcanic and sedimentary rocks under study represent a full section of oceanic plate stratigraphy (OPS): basalt (MORB, OIB)—chert (pelagic)—siliceous mudstone, siltstone and shale (hemipelagic)—trench sandstones (greywacke). The structural position and the lithology of Itmurundy rocks accord well with the model of formation of accretionary complexes at Pacific-type convergent margins, in particular, those in the western Pacific.
About the authors
I. Yu. Safonova
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Author for correspondence.
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
A. A. Perfilova
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
O. T. Obut
Novosibirsk State University; Trofimuk Institute of Petroleum Geology and Geophysics SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
I. A. Savinsky
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
R. I. Chyornyi
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
N. A. Petrenko
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
A. V. Gurova
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
P. D. Kotler
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
S. V. Khromykh
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
S. K. Krivonogov
Novosibirsk State University; Sobolev Institute of Geology and Mineralogy, SB RAS
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; Novosibirsk, 630090
Sh. Maruyama
Novosibirsk State University; Tokyo Institute of Technology
Email: inna03-64@mail.ru
Russian Federation, Novosibirsk, 630090; MeguroTokyo, 152-8550