Provenance and tectonic setting of the Early and Middle Devonian Xueshan Formation, the North Qilian Belt, China

2017 ◽  
Vol 53 (4) ◽  
pp. 1404-1422 ◽  
Author(s):  
Qian Hou ◽  
Chuanlong Mou ◽  
Qiyu Wang ◽  
Zhiyuan Tan
Keyword(s):  
Middle Devonian ◽  
Tectonic Setting ◽  
The North ◽  
North Qilian

Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study: the Laojunshan conglomerate, Qilian orogen, northwest China

2007 ◽  
Vol 44 (7) ◽  
pp. 961-986 ◽  
Author(s):  
Zhen Yan ◽  
Wenjiao Xiao ◽  
Zongqi Wang ◽  
Jilian Li
Keyword(s):  
Tibetan Plateau ◽  
Middle Devonian ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Geochemical Data ◽  
The North ◽  
Northern Tibetan Plateau ◽  
Wide Range ◽  
Qilian Orogen ◽  
North Qilian

The Qilian orogenic belt in the northern Tibetan plateau connects the Altaids to the north with the Tethyan orogenic system to the south and occupies a key tectonic position in the evolution and assembly of Asia. The belt contains a wide range of subduction–accretion-related petrotectonic units. The Early–Middle Devonian Laojunshan conglomerate, deposited unconformably upon Cambrian–Silurian strata along the northern margin of the North Qilian terrane, contains a record of the late Paleozoic tectonism of the Qilian orogen. Its provenance and tectonic setting are critical in understanding not only the tectonic evolution of Tibetan plateau, but Paleozoic global reconstructions as well. The composition of clastic conglomerates and heavy mineral assemblages of sandstones suggests that coeval mafic, felsic, metamorphic, and sedimentary rocks were the main sources. The geochemistry of volcanic clasts and paleocurrent and paleogeographic data suggest derivation from subduction–accretion complexes in the North Qilian terrane. The geochemistry of siltstones and mudstones indicates that the Laojunshan conglomerate was derived from an arc and accumulated in an active continental margin. Geochemical data of granitoid clasts suggest that they were derived from Ordovician–Silurian subduction-related magmatic rocks. Mafic and ultramafic clasts, chromite, and magnetite decrease upwards in the stratigraphy whereas metamorphic, sedimentary and granitoid clasts, and garnet increase. These data imply that mafic rocks were the predominant source during initial deposition. Regional studies suggest that the North China plate subducted southwards and produced subduction-related arc magmatism along the southern margin of the North Qilian terrane during the Early–Middle Devonian. Therefore, we interpret the Laojunshan conglomerate as a fore-arc basin fill.

Origin of chert in the Upper Ordovician–Lower Silurian: implications for the sedimentary environment of North Qilian Orogen

2021 ◽  
pp. 1-16
Author(s):  
Qian HOU ◽  
Chuanlong MOU ◽  
Zuozhen HAN ◽  
Xiangying GE ◽  
Qiyu WANG
Keyword(s):  
Volcanic Ash ◽  
Tectonic Setting ◽  
Sedimentary Environment ◽  
Late Ordovician ◽  
Upper Ordovician ◽  
Lower Silurian ◽  
The North ◽  
Qilian Orogen ◽  
North Qilian ◽  
Deep Water Basin

ABSTRACT During the Upper Ordovician–Lower Silurian, chert was widely distributed in the Zhongbao Formation in the eastern part of the North Qilian Orogen. The origin and the tectonic setting of these chert were largely unknown. In order to analyse the material provenance, sedimentary environment, their formation and the tectonic setting, we present petrology and geochemical research on chert samples collected from Shihuigou Section. The evidence provided by radiolarite occurrences, Aluminium (Al)–iron (Fe)–manganese diagram and the silicon(Si)/Si + Al + Fe + calcium ratios suggesting a non-hydrothermal input and the biogenic origin chert. The geochemical features and the petrographic signatures have shown that the chert was also influenced by a terrigenous origin. It is considered that the deposition of the Late Ordovician chert is mainly affected by tectonic collision and volcanic ash events. During the Late Ordovician–Early Silurian transition, huge amounts of volcanic ash were released by massive volcanic activity that fell into the ocean, triggering the proliferation of radiolarians. Finally, in the Late Ordovician–Lower Silurian the tectonic setting of the North Qilian Orogen was not a typical deep-water basin, nor a typical continental margin, but a multi-island deep-water basin, which is closed to the mainland.

Petrography and geochemistry of the Lower Silurian sandstones from the Angzanggou Formation in the North Qilian Belt, China: implications for provenance, weathering and tectonic setting

2019 ◽  
Vol 157 (3) ◽  
pp. 477-496
Author(s):  
Qian Hou ◽  
Chuanlong Mou ◽  
Zuozhen Han ◽  
Qiyu Wang ◽  
Zhiyuan Tan ◽  
...  
Keyword(s):  
Sedimentary Cover ◽  
Tectonic Setting ◽  
Orogenic Belt ◽  
Source Rocks ◽  
Petrographic Analysis ◽  
The Tibetan Plateau ◽  
Lower Silurian ◽  
The North ◽  
North Qilian Orogenic Belt ◽  
North Qilian

AbstractThe North Qilian Orogenic Belt is on the northeastern margin of the Tibetan Plateau. It is connected with the Alxa Block in the north and the Tethyan orogenic assemblage in the south. The Lower Silurian Angzanggou Formation, deposited in the northern area of the North Qilian Orogenic Belt, is the most important for revealing the architecture and orogenic processes of the North Qilian Belt. Provenance analysis of the Angzanggou Formation can reveal not only the tectonic evolution of the central orogenic belt of China but also Palaeozoic Asia plate reconstructions. Petrographic analysis indicated that the compositional and textural maturity of the sandstones was low. The detrital composition of the Angzanggou Formation samples consists of quartz (8–14 %), feldspar (6–29 %) and lithic fragments (56–86 %). The sandstones could be classified as litharenites or feldspathic litharenites. The detrital modal composition suggests that these sandstones were probably deposited in a fore-arc basin. The element ratios and some discrimination diagrams based on geochemistry indicate that felsic and intermediate rocks were the main source rocks. The SiO2/Al2O3 ratio, the index of chemical variability and the Th/Sc versus Zr/Sc discrimination diagram suggest that the compositional maturity and degree of recycling were moderate to low. The index of alteration (CIA) and the A–CN–K diagram indicate the intensity of weathering was moderate. The discrimination diagrams based on major and trace elements and petrographic discrimination diagrams imply that the Angzanggou Formation rocks were derived from a continental island arc, and a sedimentary cover probably overlaid the volcanic arc. Therefore, we infer that during Early Silurian time the North Qilian Belt sediments accumulated in a fore-arc basin.

Paleozoic magmatism and porphyry Cu-mineralization in an evolving tectonic setting in the North Qilian Orogenic Belt, NW China

2016 ◽  
Vol 122 ◽  
pp. 20-40 ◽  
Author(s):  
Kun-Feng Qiu ◽  
Jun Deng ◽  
Ryan D. Taylor ◽  
Kai-Rui Song ◽  
Yao-Hui Song ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Orogenic Belt ◽  
Nw China ◽  
Porphyry Cu ◽  
The North ◽  
North Qilian Orogenic Belt ◽  
North Qilian

Petrogenesis and tectonic evolution of the Palaeozoic to Mesozoic Niuxinshan granitoids in the North Qilian orogen, NW China

2021 ◽  
Author(s):  
Fan Yang ◽  
Fei Xue ◽  
M. Santosh ◽  
Zesheng Qian ◽  
Cun Zhang ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Nw China ◽  
The North ◽  
Qilian Orogen ◽  
North Qilian

scholarly journals Statherian (ca. 1714–1680 Ma) Extension-Related Magmatism and Deformation in the Southwestern Korean Peninsula and Its Geological Significance: Constraints from the Petrological, Structural, Geochemical and Geochronological Studies of Newly Identified Granitoids

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 557
Author(s):  
Byung-Choon Lee ◽  
Weon-Seo Kee ◽  
Uk-Hwan Byun ◽  
Sung-Won Kim
Keyword(s):  
Korean Peninsula ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Ductile Deformation ◽  
Southwestern Part ◽  
The North ◽  
Deformation Event ◽  
Geochemical Analyses ◽  
A Minor ◽  
T Values

In this study, petrological, structural, geochemical, and geochronological analyses of the Statherian alkali feldspar granite and porphyritic alkali feldspar granite in the southwestern part of the Korean Peninsula were conducted to examine petrogenesis of the granitoids and their tectonic setting. Zircon U-Pb dating revealed that the two granites formed around 1.71 Ga and 1.70–1.68 Ga, respectively. The results of the geochemical analyses showed that both of the granites have a high content of K2O, Nb, Ta, and Y, as well as high FeOt/MgO and Ga/Al ratios. Both granites have alkali-calcic characteristics with a ferroan composition, indicating an A-type affinity. Zircon Lu-Hf isotopic compositions yielded negative εHf(t) values (−3.5 to −10.6), indicating a derivation from ancient crustal materials. Both granite types underwent ductile deformation and exhibited a dextral sense of shear with a minor extension component. Based on field relationships and zircon U-Pb dating, it was considered that the deformation event postdated the emplacement of the alkali feldspar granite and terminated soon after the emplacement of the porphyritic alkali feldspar granite in an extensional setting. These data indicated that there were extension-related magmatic activities accompanying ductile deformation in the southwestern part of the Korean Peninsula during 1.71–1.68 Ga. The Statherian extension-related events are well correlated with those in the midwestern part of the Korean and eastern parts of the North China Craton.

Using fluvial terraces as distributed deformation offset markers: Implications for deformation kinematics of the North Qilian Shan Fault

Geomorphology ◽  
2021 ◽  
pp. 107750
Author(s):  
Xilin Cao ◽  
Xiaofei Hu ◽  
Baotian Pan ◽  
Qiming Zhao ◽  
Tai'’an Chen ◽  
...  
Keyword(s):  
Fluvial Terraces ◽  
The North ◽  
Deformation Kinematics ◽  
North Qilian
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