Early Cretaceous Adakitic Rocks in the Northern Great Xing'an Range, NE China: Implications for the Final Closure of Mongol‐Okhotsk Ocean and Regional Extensional Setting

et al. 2022

Preprint

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Apatite fission-track (AFT) tests of clastic samples from the Greater Khingan Mountains (GKM) in China show a center age of 260-62 Ma. Thermal modeling of observed fission-track-length distributions shows three stages of rapid cooling that may have been caused by extensions between 130 and 94 Ma, 30 and 15.3 Ma, and 45 and 0 Ma, and a heating event that may have been caused in part by changes in the subduction direction of the Pacific plate between 64 and 45 Ma. The cumulative exhumation since the Early Cretaceous, is approximately 3 km. The steady-state terrain model in the three-dimensional numerical simulation is highly consistent with the time and rate of the two-dimensional thermal history simulation for the Early Cretaceous exhumation event. The cooling age clusters of ˜160 to 100 Ma are similar in the GKM and Hailar-Erlian Basins.This correlation provides a basin-mountain link for the two tectonic domains. Such a basin-mountain coupling lasted through 100-42 Ma, as supported again by the shared cooling ages of samples from the GKM and detritus from the range-bounded basins on the two sides of the mountain range. We interpreted the 130-94 Ma cooling event recorded in the GKM as a result of crustal thickening in response to the closure of the Mongolia-Okhotsk Ocean. An increase in the subduction velocity of the Pacific plate since ca. 45 Ma may have created a post-arc extensional tectonic setting that has prevailed to the present in the GKM. Hosted fileessoar.10511322.1.docx available at https://authorea.com/users/535183/articles/598679-latemesozoic-cenozoic-apatite-fission-track-aft-cooling-history-of-the-greater-khinganmountains-and-its-implications-for-regional-tectonics Hosted file supplemental material.docx available at https://authorea.com/users/535183/articles/598679late-mesozoic-cenozoic-apatite-fission-track-aft-cooling-history-of-the-greater-khinganmountains-and-its-implications-for-regional-tectonics

Section: Regional Tectonic Implicationsmentioning

confidence: 96%

Late Mesozoic-Cenozoic apatite fission-track (AFT) cooling history of the Greater Khingan Mountains and its implications for regional tectonics

Wang

et al. 2022

Preprint

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“…Furthermore, the geological history of Northeast China has been shaped by the convergence and subduction of two major tectonic plates, the Mongolia-Okhotsk plate and the Paleo-Pacific plate, towards the Eurasian continent since the Late Jurassic period. These geological events have played a crucial role in the formation and evolution of the region, leading to the development of complex geological structures and the sediment of diverse rock types [7][8][9][10][11][12][13][14]. Northeast China has a long and complex tectonic evolution, and thus plays a key role in studying the history of the three tectonic domains present in the region.…”

Section: Introductionmentioning

confidence: 99%

Late Triassic Tectonic Setting in Northeastern Margin of North China Craton: Insight into Sedimentary and Apatite Fission Tracks

Tang

et al. 2023

Minerals

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The closure timing of the Paleo-Asian Ocean and the terminal stage of the Central Asian Orogenic Belt have been widely debated in the geological community. It’s known that the gradual scissor-like closure of the Paleo-Asian Ocean occurred from west to east during the Paleozoic period. However, it was not until the Triassic period that the complete closure of the ocean occurred at the northeastern margin of the North China Craton. Nevertheless, there is still much uncertainty regarding the Late Triassic tectonic setting in Northeast China. In this study, we focused on the Upper Triassic Dajianggang Formation, located in the Shuangyang area of central Jilin Province, which is situated on the northeastern margin of the North China Plate. Our aim was to determine the formation age of the Dajianggang Formation by analyzing the detrital particle composition, petrogeochemistry, detrital zircon U-Pb isotope dating, and apatite fission track thermochronology. Our results indicated that the primary sandstone provenance area of the Dajianggang Formation in the Shuangyang area is the island arc orogenic belt. The tectonic background of the sandstone provenance area is mainly a continental island arc environment. The provenance area is mostly composed of felsic rocks with sedimentary tendencies, and some of its material may have originated from the northern margin of the North China Craton or the eroded recycle orogenic belt. LA-ICP-MS U-Pb dating of detrital zircons shows that the Dajianggang Formation formed after 226.8 ± 5 Ma. Moreover, analysis of the thermal evolution history modelling shows that the Dajianggang Formation in the Shuangyang area continued to be deposited and heated in the early stage, and then experienced rapid exhumation around 30 Ma. This suggests that the study area underwent an orogenic process during the early stage of formation, but then transitioned into a post-orogenic extension period, which constrained the final closure of the Paleo-Asian Ocean prior to the Late Triassic period. In addition, our study indicates that the remote effect of the Pacific subduction did not reach the study area until 30 Ma. The central age of the detrital apatite fission track of sample 19DJ-1 is 94.2 ± 8.3 Ma, which is younger than its corresponding stratigraphic age. The two peak ages of the fission track analysis are 62.9 ± 5.4 Ma and 126 ± 11 Ma. These findings provide new evidence for the tectonic evolution of Northeast China and shed light on the Late Triassic tectonic setting, as well as the influence time of subsequent tectonic domains in the southern part of Northeast China.

“…However, as the basin boundary is far away from the two subduction zones, whether and how these two tectonic domains exerted control on the growth of the basin remains controversial (Li, Xu, et al, 2020; Xu et al, 2013). Several geodynamic mechanisms have been proposed to explain the formation and evolution of the Songliao Basin, including (a) subduction and the rollback of the Palaeo‐Pacific Plate (Ji, Meng, Wan, Ge, et al, 2019; Ji, Meng, Wan, Zhu, et al, 2019); (b) the influence of mantle plume activity (Ge et al, 1999) or other intraplate processes (Shao et al, 2001); (c) subduction of the Mongol–Okhotsk Oceanic plate or lithospheric extension after the closure of the Mongol–Okhotsk Ocean (Feng et al, 2021; Zhang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

“…Several geodynamic mechanisms have been proposed to explain the formation and evolution of the Songliao Basin, including (a) subduction and the rollback of the Palaeo-Pacific Plate Ji, Meng, Wan, Zhu, et al, 2019); (b) the influence of mantle plume activity (Ge et al, 1999) or other intraplate processes (Shao et al, 2001); (c) subduction of the Mongol-Okhotsk Oceanic plate or lithospheric extension after the closure of the Mongol-Okhotsk Ocean (Feng et al, 2021;Zhang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Development of Songliao Basin by Palaeo‐Pacific slab rollback: Evidence from Early Cretaceous rhyolites in SK2 Borehole, NE China

Huang

et al. 2022

Geological Journal

As the largest petroliferous basin in northeast (NE) China, Songliao Basin preserves continuous Cretaceous sedimentary-volcanic records, providing an excellent opportunity to recover the palaeo-environment. The Yingcheng Formation in the Songliao Basin contains ample gas reservoirs that attract widespread attention. Whereas the timing, petrogenesis and geodynamic mechanism of the volcanic rocks in the Yingcheng Formation are still controversial, which largely constrain our understanding of the formation and evolution of the Songliao Basin. Here, we present an integrated investigation of zircon U-Pb ages and Hf isotope, as well as whole-rock elements and Sr-Nd isotopes data for a suite of rhyolites of Yingcheng Formation from the SK2 Borehole of NE China. Zircon U-Pb age dating results of nine samples have yielded a concentrated age of $110 Ma. These Yingcheng rhyolites are characterized by high SiO 2 (66-78 wt%) and alkali (Na 2 O + K 2 O = 7.80-11.70 wt%) content, high 10000*Ga/Al (1.26-3.82, mostly >2.6) and FeO T /(FeO T + MgO) ratios (0.81-0.95), which show geochemical affinities with A-type rhyolites. They have relatively low Y/Nb (0.69-1.78, average 1.19) and Rb/Nb (1.58-6.52, average 4.34) ratios, suggesting that the Yingcheng volcanic samples belong to A 1 -type rhyolites which formed in an intraplate environment. These Yingcheng rhyolites show depleted Nd-Hf isotopic compositions (ε Nd (t) = 2.43-4.87 and zircon ε Hf (t) = 4.22-9.88) comparable with the Early Cretaceous A-type and I-type rhyolites in the Songliao Basin, suggesting that they were originated from a juvenile continental crust. They were most likely derived from the partial melting of anhydrous lower crust instead of differentiation of mantle-derived or mixing with alkaline basaltic magma, due to their low Mg # and absence of the coeval mafic rocks. Combined with the previous studies, A-type rhyolites in the Yingcheng Formation erupted lasting at least 10 Myr and were widely distributed in the rifts of the Songliao Basin. We propose that the Yingcheng rhyolites were most likely generated from the rollback of the Palaeo-Pacific Plate in the Early Cretaceous, thus highlighting the significance of the subduction of the Palaeo-Pacific Plate during the secular evolution of the Songliao Basin.