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Lithic fragments of mineralized sandstones in the Kamust uranium deposit. (a) G porphyry fragments with porphyritic structure. Phenocrysts are quartz and feldspar, and th is a fully crystalline structure. (b) Granite fragments composed of quartz and feldspar. (c) P talline quartz. (d) Quartz schist fragments with a small amount of sericite and flake structu potassium feldspar fragments on the left. (e) Metamorphic siltstone fragments. (f) Siliceou composed of microcrystalline quartz. (g) Andesite fragments with interlaced structure. (h) R fragments with faintly visible flow structure, and the matrix is a fine structure interspers quartz veins. (i) Pyroclastic fragments, containing a large number of crystal pyroclasts.
Source publication
The uplift and denudation history of the orogenic belt and the basin–mountain coupling process have directly or indirectly affected the generation, scale, and preservation of sandstone-type uranium deposits in the eastern Junggar Basin by controlling the uranium source, lithology, facies, hydrogeology, post-generation modification, and other minera...
Contexts in source publication
Context 1
... sand grains have good sorting, medium roundness, and subangular sphericity and are mainly composed of lithic grains, quartz, and feldspar, with clay cementation and loose consolidation. The lithic grains of sandstone are mainly composed of a large number of acid magmatic lithologies (Figure 3), of which granite porphyry and granite material account for more than 50%, rhyolite, andesite, and pyroclastic material account for approximately 20%. Metamorphic material accounts for approximately 10%, with a small amount of sedimentary material. ...
Context 2
... sand grains have good sorting, medium roundness, and subangular sphericity and are mainly composed of lithic grains, quartz, and feldspar, with clay cementation and loose consolidation. The lithic grains of sandstone are mainly composed of a large number of acid magmatic lithologies (Figure 3), of which granite porphyry and granite material account for more than 50%, rhyolite, andesite, and pyroclastic material account for approximately 20%. Metamorphic material accounts for approximately 10%, with a small amount of sedimentary material. ...
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Citations
... Fan delta deposits occur in the northwestern basin, while deltaic and aeolian dune deposits are present in the eastern basin (Figure 13d; Eberth et al., 2001;Vincent & Allen, 2001;Xu et al., 2022). In the late stage, the lakes expanded, and lacustrine and deltaic environments dominated the whole Junggar Basin (Figure 13e; Du et al., 2019;Li et al., 2017;Liu et al., 2022;Xing et al., 2013). Lakeshore aeolian deposits are present in the northwestern Junggar Basin and Turfan-Hami Basin (this study; Shen et al., 2020). ...
Aridification of Central Asia in the Late Mesozoic led to drastic environmental changes characterized by widespread aeolian deposits. We systematically investigated fluvial‐aeolian deposits in the Middle Jurassic Toutunhe Formation, Upper Jurassic Kalazha Formation, and Lower Cretaceous Tugulu Group in the Junggar Basin to the north of the Tianshan Orogenic Belt via unmanned aerial vehicle‐based photogrammetry, scanning electron microscope, grain‐size analysis, and detrital zircon geochronology. Paludal and deltaic environments transitioned to a fluvial‐aeolian environment from the late Middle Jurassic to the Late Jurassic. Fan delta and incisive braided river deposits accumulated in the earliest Cretaceous and evolved into a lacustrine environment with aeolian deposits in the lakeshore. Aeolian deposits are characterized by moderate‐ to well‐sorted and subangular to subround sandstones with large‐scale, high‐dip cross‐bedding, inversely graded lamination, dominant saltation grains, crescent‐shaped, and dish‐shaped impact structures. Aeolian deposits contain heavy minerals including more ilmenite, zircon, garnet, and, tourmaline and less magnetite and epidote than the fluvial deposits. The preserved aeolian sediments of the Kalazha Formation extend west–east for more than 100 km, suggesting a wide desert area during the latest Jurassic. The detrital zircon age patterns indicate that the provenance of the aeolian deposits was similar to that of coeval fluvial deposits. The cooccurrence of fluvial and aeolian deposits and the similar provenances but orthogonal flow directions indicate that the aeolian deposits were mainly sourced from the nearby fluvial material within the basin. The evolution of the fluvial‐aeolian system responded to a complete base‐level cycle controlled by the aridification and tectonics. Due to decreased sediment supply caused by aridification, the base level rose, leading to the change from braided rivers to meandering rivers, along with the deposition of aeolian sediments. Due to the tectonic reactivation in the Late Jurassic, the base level fell, causing the occurrence of alluvial fans and the expansion of the aeolian sediments. Previous studies revealed that the Tianshan in the Jurassic exhibited low relief. The fluvial‐aeolian system played an important role in maintaining the limited relief in southern Central Asia.
... Uranium is a radioactive-lithophile metal which occurs in many geologic formations; including metamorphic, magmatic, and sedimenatry rocks (e.g., [1][2][3][4]). It forms interesting concentrations in some plants, water, soils, sediments, bitumens, coals, and fossil woods [5][6][7][8][9][10][11][12]. This element is mined in some and titanite [2]. ...
U-bearing syenitic rocks cropping at the Mbanga Massif in the South Region of Cameroon were geochemically and mineralogially charactarized, before determination of their radiometric data, and processing of their uranium ores by H2SO3 acid leaching. The syenitic rocks are alkaline syenite, high-K syenite, and alkaline quartz syenite, with the first two rocks being metaluminous and the third, peraluminous. Both rocks show a compositional difference in uranium abundances (133- 447 ppm) and those of other elements in wt.% (e.g., SiO2 : 61.6-66.6, Al2O3: 16.9-17.9, Fe2O3: 1.9-3.9, MgO: 0.4-1.3, CaO: 1.5-3.4, Na2O: 4.7-9.7, and K2O: 0.1-6.4) and in ppm ( e.g., Zr: 111-599.7, Rb: 4.5- 287, Ba : 100.1-399, Sr: 157.1-999, V: 16.1-131, Pb:30.9-121.5, and Th: 12.0-27.6). The ƩLREE (37.3- 168 ppm), ƩHREE (8.7- 22.2 ppm), ƩLREE/ ƩHREE (1.6-13.8), and Eu/Eu* < 0.4 values are also variable. U-ore minerals (uraninite, uranophane, autunite, coffinite, carnotite, torbernite, and/or coffinite) are associated with other ore minerals (U-rich titanium oxide, zircon, magnetite, and/or ilmenite) in a gangue made up of chlorite, calcite, quartz, alkaline feldspar, albite, plagioclase, and/or biotite. The uranium contents (< 465 ppm) in the studied U-bearing syenites classified them within low grade ores; suggested to have formed with the aid of circulating hydrothermal fluids source of the precipitated OH, H2O, and OH-H2O bearing uranium ore minerals. The measured raw radiometric values range from 3542-6600 c/s and U3O8, from 0.33-0.59 wt.%. Samples with U3O8 ≥ 0.54 wt.% were found interesting for uranium industries. The presence of some minerals in the studied ores and the use of oxidant such as manganese dioxide during the H2SO3 acid leaching, provided elements which positively impact the process by increasing the U extraction with a total recovery of 80-90 %. The maximum leaching temperatures 40-60 oC were less compared to those used to process some other low grade uranium ores.
... They are characterized by shallow depth, large-scale reserves and low cost of mining [2,3]. At present, there are a series of studies on the geological conditions, mechanisms, and basin characteristics of sandstone type uranium deposits [4,5]. However, the deep prediction on its mineralization model and ore body size are in the exploratory stage [6]. ...
Sandstone type uranium is the most valuable and has the most potential for mining among the known uranium deposits. In the process of forming, the hydrolytic migration and enrichment of uranium require special basin sedimentary environment and tectonic background. Therefore, the mineralization process of sandstone type uranium deposits has certain layering characteristics and distribution rules in the underground vertical depth space. It is important to mine the spatial distribution characteristics of vertical uranium-bearing layers, and thus, reconstruct the three-dimensions of uranium orebodies. In this paper, according to the metallogenic law and distribution characteristics of sandstone type uranium in the underground vertical space, a nonlinear uranium-bearing layers identification (NULI) method of sandstone type uranium is proposed by using different types, resolutions and scales of borehole data. Then, the depth of uranium mineralization for the Daying uranium deposit within northern Ordos Basin is identified accurately and the spatial distribution characteristics of the uranium-bearing layer on the exploration line are obtained. Finally, the occurrence mode of the underground uranium orebodies are presented by using three-dimensional reconstruction analysis. It provides a basis for the prediction, exploration and mining of sandstone type uranium deposits within the Ordos Basin.
