PALEOZOIC TECTONICS AND GEODYNAMICS OF VOLCANIC ARCS IN NORTHERN KAZAKHSTAN
V.V. Korobkin and A.V. Smirnov*
Kazakhstan-British Technical University, 59 ul. Tolibi, Alma-Ata, 480091, Kazakhstan
* Institute of Natural Resources, 168 ul. Bogembai Batyra, Alma-Ata, 480012, Kazakhstan
Keywords: Island arc, microcontinent, accretion, collision, thrust, olistostrome, suture zone, nappe
Pages: 458-470
Abstract
Based on summarized and correlated structural, paleogeographical, and geochronological data, we propose new concepts of the intricate multistage Cambrian-Middle Ordovician evolution of an island-arc system in northern Kazakhstan. It is shown that in the Early Ordovician, the Selety island arc was rebuilt to give rise to the Stepnyak island arc. This rebuilding was intimately related to the collision of the Selety island arc with the Kokchetav microcontinent, which led to the formation of a nappe-thrust structure, exhumation of high- and ultrahigh-pressure rocks, and jump of subduction zone with the emergence of a new island arc.
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