Detrital zircon U-Pb ages of Paleozoic sedimentary rocks from the eastern Hexi Corridor Belt (NW China): Provenance and geodynamic implications

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• 作者：Xiaochen Zhao ; ^{zxcnwu@126.com" class="auth_mail" title="E-mail the corresponding author} ; Chiyang Liu ; Jianqiang Wang ; Yan Zhao ; Lei Wang ; Qihang Zhang
• 关键词：Eastern Hexi corridor ; Paleozoic ; Detrital zircon ; Tectonic evolution ; Eastern Gondwana
• 刊名：Sedimentary Geology
• 出版年：2016
• 出版时间：15 June 2016
• 年：2016
• 卷：339
• 期：Complete
• 页码：32-45
• 全文大小：4167 K

文摘

The Paleozoic tectonic framework of the eastern Hexi Corridor Belt is ambiguous. However, thick Paleozoic sediments from the eastern Hexi Corridor Belt can provide clues to this problem. In this paper, we deal with the detrital zircon provenance of Middle Ordovician to Late Devonian strata using LA-ICP-MS U–Pb dating, documenting the temporal and spatial changes of provenance. Detrital zircon U–Pb ages indicate that the primary provenance was the Qilian Orogenic Belt and the Alxa Block. However, two samples from Late Devonian strata show different provenance characteristics, from the North Qilian Orogenic Belt, and the Alxa Block and the North China Block, respectively. Different age distributions through time reflect provenance changes due to continuous convergence of the Central Qilian Block and the Alxa Block from the Middle Ordovician to Late Devonian. A significant age cluster ranging from 2000 to 1800 Ma, which is a detrital zircon signature of the North China Block, appeared in the Late Devonian Zhongning Formation. Our preferred interpretation is that the amalgamation of the Alxa Block and the North China Block likely occurred at that time. Moreover, similar Paleozoic fossils, paleolatitudes and detrital zircon distribution indicate that the Hexi Corridor Belt has an affinity to eastern Gondwana.