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Ordovician supra-subduction, oceanic and within-plate ocean island complexes in the Tekturmas ophiolite zone (Central Kazakhstan): age, geochemistry and tectonic implicationsстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Degtyarev Kirill, Yakubchuk Alexander S., Luchitskaya Marina V., Tolmacheva Tatiana Yu, (Pilitsyna) Anfisa V.Skoblenko, Tretyakov Andrey A.
- Журнал: International Geology Review
- Том: 64
- Номер: 15
- Год издания: 2021
- Издательство: Taylor & Francis Group
- Местоположение издательства: Abingdon, U.K., England
- Первая страница: 2108
- Последняя страница: 2150
- DOI: 10.1080/00206814.2021.1969691
- Аннотация: The Junggar-Balkhash region in the west of the Central Asian orogenic belt comprisesPalaeozoic flysch, dismembered ophiolites, chert, basalt, and olistostrome within its accretionarywedges. The Tekturmas ophiolite zone in the north of the Junggar-Balkhash regionhosts Ordovician to Early Silurian complexes, mostly formed with a convergent margin infront of the Baydaulet-Akbastau magmatic arc. The northern part of the Tekturmas zonecomprises Middle to Late Ordovician (465–455 Ма) Bazarbai supra-subduction (SSZ) ophiolites,which were formed in the fore-arc settings. At the south of the Tekturmas zone EarlyOrdovician (~470 Ма) Tortaul SSZ ophiolites, Middle Ordovician Karamurun oceanic islandbasalts (OIB) and Middle to Late Ordovician Tekturmas deep water cherts are present. Thereare also concurrent Middle Ordovician (~460 Ma) high-temperature granulites, related toa partial melting of the subducted metasedimentary complexes.Since the second half of the Late Ordovician until the Early Silurian, the stratigraphic data constrain in front of the Baydaulet-Akbastau island arc the emergence of the Nura fore-arc trough.In the north of the Tekturmas zone, it is represented by the chert-tuffaceous Bazarbai Formation; southward, the zone can be interpreted as a concurrent accretionary wedge made up by the fragments of the Bazarbai and Tortaul ophiolites, Karamurun OIB basalts, and Tekturmas deep water cherts, accompanied by chaotic olistostrome. In the Early Silurian, growth of the accretionary wedge migrated to the south into the Uspenskу zone.We propose that while subduction was steadily directed underneath the Baydaulet-Akbastauisland arc, the near-surface thrusting OIB and deep water cherts was also directed northward ontothe fore-arc in the Late Ordovician to the earliest Silurian, whereas from the middle Llandovery it reversed southwards.In the end of the Palaeozoic to the Mesozoic, the Tekturmas ophiolite zone was offset intoa number of segments by the sinistral strike-slip faults.
- Добавил в систему: Якубчук Александр Сергеевич