The Itmurundy Accretionary Complex, Northern Balkhash Area: Geological Structure, Stratigraphy and Tectonic Origin

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 (...

Full description

Saved in:
Bibliographic Details
Published in:Russian journal of Pacific geology 2019-05, Vol.13 (3), p.283-296
Main Authors: Safonova, I. Yu, Perfilova, A. A., Obut, O. T., Savinsky, I. A., Chyornyi, R. I., Petrenko, N. A., Gurova, A. V., Kotler, P. D., Khromykh, S. V., Krivonogov, S. K., Maruyama, Sh
Format: Article
Language:English
Subjects:
Accretion
Active margins
Basalt
Chert
Deformation
Earth and Environmental Science
Earth Sciences
Fault lines
Faults
Geological structures
Geological time
Geology
Lithology
Mantle
Mudstone
Sandstone
Sedimentary rocks
Shale
Siltstone
Stratigraphy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 (O 1-2 ), Kazyk (O 2-3 ) and Tyuretai (O 3 -S 1 ). 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. (O 1-2 ) 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 2 nd and 3 rd 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.
ISSN:1819-7140
1819-7159
DOI:10.1134/S1819714019030072