Late Paleozoic Tectonic Evolution of the Qinling Orogenic Belt: Constraints of Detrital Zircon U-Pb Ages from the Southern Margin of North China Block

Abstract

The tectonic evolution of the Qinling Orogenic Belt in the Late Paleozoic has long been controversial, especially due to the limitation of the Mianlue Ocean subduction time. Basin formation and sedimentary development in the southern North China Block are closely related to the tectonic evolution of the Qinling Orogenic Belt, which is an effective entry point to study basin–mountain interaction. We present new detrital zircon U–Pb data from the Shihezi Formation in the Luonan area in the southern margin of the North China Block. The results show that the bottom sample has two major peaks at 288 Ma and 448 Ma, with weak peaks at 908, 1912 Ma and 2420 Ma. The top sample has one major peak at 297 Ma, with weak peaks at 1933 Ma and 2522 Ma. Combined with the published paleocurrent data and lithofacies paleogeography, the sediments of the bottom sample were sourced from the North Qinling Belt, Inner Mongolia Palaeo-Uplift and the basement of the North China Block. The top sample originated mainly from the Inner Mongolia Palaeo-Uplift and the basement of the North China Block. Comparing the obtained zircon U-Pb ages with the published relevant data in the North China Block, it is found that the provenance area shifted from the Qinling Orogenic Belt to the Inner Mongolia Paleo-Uplift in the Late Carboniferous–Permian, and the Qinling Orogenic Belt could hardly provide provenance for the southern North China Block in the Middle Permian. The uplift of the Qinling Orogenic Belt in the Late Carboniferous may be the continuation of Caledonian orogeny in the Early Paleozoic, whereas the uplift of the Inner Mongolia Palaeo-Uplift is related to the tectonic evolution of the Central Asian Orogenic Belt during the Late Paleozoic. This tectonic transformation occurred when the Qinling Orogenic Belt no longer supplied sediments to the southern North China Block in the Middle Permian, and the Mianlue Ocean subduction did not occur until at least the Late Permian.

Early Jurassic initiation of the modern drainage pattern of the Dabie orogen (East China) revealed by a multi‐proxy provenance approach

“…(2022) and from Wang et al. (2023) for the Yueshan Basin. All ages are displayed on the KDEs and histograms with a 20 Ma KDE bandwidth.…”

Organic and Inorganic Geochemistry of Upper Paleozoic Marine-to-Continental Transitional Shales and the Implications for Organic Matter Enrichment, Ordos Basin, China

“…The shales in the Shanxi formation were mainly deposited in the delta plain and delta front in a warm and humid climate. Due to the continuous uplift of the Yinshan Uplift in the north, the provenance supply becomes easy by fluvial processes. , Rivers carried extensive terrestrial sediments and organic matter that contributed to shale deposition. Research shows that terrestrial organic matter (plant waxes, lignins, and other substances) is more resistant to microbial decomposition, and the oxidation degradation rate is lower than that of marine organic matter. − In a study evaluating the sensitivity of terrestrial organic matter to oxidative degradation in the sedimentary environment, Prahl et al.…”

“…Due to the continuous uplift of the Yinshan Uplift in the north, the provenance supply becomes easy by fluvial processes. 39,40 Rivers carried extensive terrestrial sediments and organic matter that contributed to shale deposition. Research shows that terrestrial organic matter (plant waxes, lignins, and other substances) is more resistant to microbial decomposition, and the oxidation degradation rate is lower than that of marine organic matter.…”

“… The Qinling Orogenic Belt and the Inner Mongolia Paleo-uplift together provided extensive terrigenous sediment for the Ordos Basin, while sediments in the northern part of the Ordos Basin were mainly sourced from the northern Inner Mongolia Paleo-uplift, also known as the Yinshan Uplift (Figure ). , An epicontinental sea was developed across the whole North China Craton from the Carboniferous to the Permian, with frequent fluctuations in sea levels. , Stacked deposits of sandstones, shales, and coals developed in a variety of depositional environments, including barrier–coastal and fluvial–delta facies (Figure ). …”

Detrital zircon U–Pb geochronology and geochemistry of sandstones in the Siziwang Banner, Central Inner Mongolia: Implication for tectonic evolution

“…Over its tectonic evolution, this region developed within the framework of the PAO tectonic system. Furthermore, it underwent the complex superposition of the Mongolia-Okhotsk Ocean tectonic system and the Palaeo-Pacific tectonic system since the Mesozoic era (Chen et al, 2009;Sengör et al, 1993;Wang, 2014Wang, , 2021. This complicated history of "three systems, two superpositions" has transformed it into a significant area for studying the tectonic evolution of the PAO tectonic, Okhotsk tectonic, and the Palaeo-Pacific domains (Chen et al, 2009;Jian et al, 2008;Li, 2006;Miao et al, 2007Miao et al, , 2008Sengör et al, 1993;Tang, 1989;Xiao et al, 2003;Xu et al, 2015).…”