Intracontinental deformation of the western Ordos Basin in North China and sandstone‐type uranium mineralization: Constraints from AFT chronology of the Helan Mountain

The Paleozoic strata are widely distributed in the northwest of the Ordos Basin, and the provenance attributes of the basin sediments during this period are still controversial. In this paper, the detrital zircon LA-MC-ICPMS U-Pb age test was conducted on the drilling core samples of the Shanxi Formation of the Upper Paleozoic in the Otuokeqi area of the Ordos Basin, and the provenance age and the characteristic of the Shanxi formation in the Otuokeqi area in the northwest were discussed. The cathodoluminescence image shows that the detrital zircon has a clear core-edge structure, and most of the cores have clear oscillatory zonings, which suggests that they are magmatic in origin. Zircons have no oscillatory zoning structure that shows the cause of metamorphism. The age of detrital zircon is dominated by Paleoproterozoic and can be divided into four groups, which are 2500~2300 Ma, 2100~1600 Ma, 470~400 Ma, and 360~260 Ma. The first two groups are the specific manifestations of the Precambrian Fuping Movement (2.5 billion years) and the Luliang Movement (1.8 billion years) of the North China Craton. The third and fourth groups of detrital zircons mainly come from Paleozoic magmatic rocks formed by the subduction and collision of the Siberian plate and the North China plate. The ε Hf t value of zircon ranges from -18.36 to 4.33, and the age of the second-order Hf model T DM 2 ranges from 2491 to 1175 Ma. The source rock reflecting the provenance of the sediments comes from the material recycling of the Paleoproterozoic and Mesoproterozoic in the crust, combined with the Meso-Neoproterozoic detrital zircons discovered this time, indicating that the provenance area has experienced Greenwellian orogeny.

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Middle Triassic lake deepening in the Ordos Basin of North China linked with global sea-level rise

Global and Planetary Change ◽

10.1016/j.gloplacha.2021.103670 ◽

2021 ◽

pp. 103670

Author(s):

Xin Jin ◽

Viktória Baranyi ◽

Marcello Caggiati ◽

Marco Franceschi ◽

Corey J. Wall ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

North China ◽

Middle Triassic ◽

Ordos Basin ◽

The Ordos Basin ◽

Global Sea Level

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Geological and Geochemical Characteristics of the Zhiluo Formation in the Bayinqinggeli Uranium Deposit, Northern Ordos Basin: Significance for Uranium Mineralization

Acta Geologica Sinica - English Edition ◽

10.1111/1755-6724.14856 ◽

2021 ◽

Author(s):

Yuqi CAI ◽

Meizhi HAN ◽

Chuang ZHANG ◽

Chao YI ◽

Xiaocui LI ◽

...

Keyword(s):

Uranium Deposit ◽

Ordos Basin ◽

Uranium Mineralization ◽

Geochemical Characteristics

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Geological Controls on Mineralogy and Geochemistry of the Permian and Jurassic Coals in the Shanbei Coalfield, Shaanxi Province, North China

Minerals ◽

10.3390/min10020138 ◽

2020 ◽

Vol 10 (2) ◽

pp. 138

Author(s):

Yunfei Shangguan ◽

Xinguo Zhuang ◽

Jing Li ◽

Baoqing Li ◽

Xavier Querol ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

North China ◽

Ordos Basin ◽

Source Region ◽

Atomic Emission ◽

Shaanxi Province ◽

Emission Spectrometry ◽

Plasma Atomic Emission Spectrometry ◽

X Ray ◽

Diagenetic Fluid

Coal as the source of critical elements has attracted much attention and the enrichment mechanisms are of significant importance. This paper has an opportunity to investigate the mineralogical and geochemical characteristics of the Permian and Jurassic bituminous coals and associated non-coals from two underground coal mines in the Shanbei Coalfield (Northeast Ordos basin), Shaanxi Province, North China, based on the analysis of X-ray diffraction (XRD), inductively coupled plasma atomic-emission spectrometry (ICP-AES/MS), and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The Jurassic and Permian coals have similar chemical features excluding ash yield, which is significantly higher in the Permian coals. Major mineral matters in the Jurassic coals are quartz, kaolinite, and calcite. By contrast, mineral assemblages of the Permian coals are dominated by kaolinite; and apatite occurring in the middle section’s partings. The Jurassic coals are only enriched in B, whereas the Permian coals are enriched in some trace elements (e.g., Nb, Ta, Th, and REY). Boron has a mixed inorganic and organic association which may be absorbed by organic matter from fluid (or groundwater) or inherited from coal-forming plants. Additionally, climatic variation also plays an important role. As for the Permian coals, kaolinite and apatite as the major carriers of elevated elements; the former were derived from the sedimentary source region (the Yinshan Oldland and the Benxi formation) and later precipitated from Ca-, and P-rich solutions. We deduced that those elevated elements may be controlled by the source rock and diagenetic fluid input. The findings of this work offered new data to figure out the mechanism of trace element enrichment of coal in the Ordos basin.

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