[en] The tectonic evolution is divided into four stages at the southern margin of Turpan-Hami basin: (1) the development of Xinjiang oldland; (2) the sedimentation of passive-continental margin in the south of Junggar (Turpan-Hami) plate; (3) the accretion nappes of the force-arc margin and the development of foreland-like basin in the island (C₂-T); (4) the development of sub-orogenic belt and the slope zone (J-Q). The third stage provided favourable material source and the emplacement space for interlayer oxidized zone-type uranium deposit. The fourth stage of the tectonic evolution was the time for the formation of intramountain basin and controlled the occurrence of the interlayer oxidized zone and sandstone-type uranium deposit

[en] For lack of the quantitative comparison of metallogenetic geologica setting between the controlled area and the prediction area, the abundance model method used for the prediction of mineral resource often has much error and inconsistency with the reality. A new parameter, the coefficient of metallogenetic ability, is preliminarily introduced for correction of the abundance model. The corrected abundance model is used in LSS metallogenetic zone and an estimation of uranium resource with better precision is obtained

[en] The Late-reformation stages, types, distribution features in Ordos Basin are researched based on contact relation, sedimentary formation, tectonic deformation, main tectonic disturbance and isotopic age determination. Late-reformation of Ordos Basin occurs after Middle-Late Jurassic Epoch,and are divided into 5 phase, such as Late Jurassic, early Cretaceous, early Cretaceous end-paleocene epoch, Eocene epoch -miocene epoch, Miocene epoch-now. the main Late-reformation types are uplifting and weathering, thrust fold, fault depression ,deep burial with superimposition, and thermodynamic reforming. their space distributions are uniformity. Relationship between the Late-reformation and Sandstone-Type Uranium deposits are analyzed to think that Multi-uplifting and weathering after Middle-Late Jurassic Epoch controlle the formation of Sandstone-Type Uranium deposits, specially, uplifting tilting area confroled the space distribution of sandstone-type Uranium deposits, but thrust fold, fault depression, deep burial with superimositon is unfavorable to metallogenetic of sandstone-type Uramium, because the later change the form, depth of bearing-ore layers local groundwater discharge. (authors)

[en] It is considered that the calcareous sandstone appear at layer along of a bunch of pear lens on and off, localled near up and down surface of sandbody or washed surface, has sandstone of more macro-grain and more gradation through statistics and analysis of calcareous sandstone in goal layer in Shihongtan uranium deposits. The calcareous sandstone accumulation thickness chorogram demonstrated that the calcareous sandstone centralized distribution in the ore body growth area, thus it can be seen, in the oxidation reduction intermediate belt the calcareous sandstone forms with the uranium mine has the certain origin relation. Choropleth map of summed thickness of calcareous sandstone deserves that it mainly appear in area of uranium body and related cause of formation of ore body of interlayer deacidizing--oxidation belt. (authors)

[en] Hui'anbu Uranium deposit produced in the Zhiluo Formation sandstone of middle Jurassic series in Ordos Basin. The methods of radioactive α-track camera and electronic probe are used to study uranium minerals existing forms that are main adsorption with a few pitchblende. The paragenetic association of Uranium minerals has eight forms. Absorptive uranium is related with the Fe-Ti oxide, pyrite and clay. Fe-Ti oxides are mostly fragmentary white titanium rock containing uranium. Some altered Fe-Ti oxides are replaced by pyrite and retain metasomatic texture obviously. Fe-Ti oxide replaced by pyrite in the rock has a strong reduction and adsorption capacity, so it becomes a favorable medium of enriching uranium. The uraniferous Fe-Ti oxide and its alteration products are the major enriching uranium reagent. Through analyzing mineralization, the existence of plenty Fe-Ti oxides may be one of the evaluation criteria of ore-bearing potentiality. (authors)

[en] Based on the observation and statistics on the calcareous sandstone in the ore host layer in Shihongtan uranium deposit, this paper finds that the calcareous sandstone occurs on and off near the top or wash surface of the sandbody as beads-strings lens along the layer and concentrates in the area where the ore bodies are rich. In lithology, the calcareous sandstone is of coarse grain and fairly well sorted. According to the analysis on the lithogeochemical features and the carbon and oxygen isotopes of calcareous sandstones, it is realized that there some genetic relation between the formation of calcareous sandstone and uranium mineralization in the oxidation-deoxidation transitional belt, that is the precipitation and enrichment of uranium is accompanied by the deposition of carbonate and formation of calcareous sandstone. (authors)

[en] Interlayer oxidation zones in the southwenter Tupan-Hami basin bears very evident zonation, according to the mineral combination and geochemical character, the zones can be devided into oxidation zone, redox transition zone and deoxidation zone, and the oxidation zone can be discriminated into fully- oxidized and partly-oxidized subzones. Mineral combination and geochemical character are different in each zone and typical elements U, Th, ΣS, C, Se, Mo, Re, CaO, CO₂ bear obvious distribution pattern. The orebodies are controled strictly by oxidation-deoxidation area and mainly occur in the redox transition zone and partly-oxidized subzones as irregular roll, tabula and lenticula. (authors)

[en] Through studying the structural evolution, structural characteristics of Shihongtan sandstone-type uranium deposit, it is found that there are three types of structural controls on Shihongtan sandstone-type uranium deposit on the Aiding structural slope, namely, the uranium sources, types of the sedimentary formation of target horizons and the mineralization epochs are controlled by the structural evolution of the basin; the mineralization area are controlled by the structural slope units; the distribution of uranium ore bodies is controlled by the second order structures on the structural slope. (authors)

[en] Based on the study of geologic characteristics of Shihongtan U-deposit, authors suggest that the deposit is a typical interlayer oxidation zone sandstone-type U-deposit, and the ore-formation is mainly controlled by ore-controlling factors such as the uranium source, the development of interlayer oxidation zone, the variation of hydrodynamic conditions etc. On the basis of summarizing these ore-controlling factors, the authors have set up a metallogenic model of the Shihongtan U-deposit. (authors)

[en] By comprehensively analyzing metallogenic environments and main ore-controlling factors of important uranium metallogenic regions of in-situ leachable sandstone-type uranium deposits at the southern margin of Yili basin, at the south-western margin of Turpan-Hami basin and in the northeastern Ordos basin, the authors of this paper discuss the metallogenic models of China's in-situ leachable sandstone-type uranium deposits, and suggest that the interlayer oxidation zone type uranium deposits in Yili and Turpan-Hami basins are basically controlled by favourable structures, sedimentary formations and interlayer oxidation zone, and are characterized by multistage uranium concentration, namely the uranium pre-concentration of ore-hosting sedimentary formation, the uranium ore-formation in the stage of supergenic epigenetic reworking, and the further superimposition enrichment of post-ore tectonic activity. However, the interlayer oxidation zone type uranium deposit in the northeastern Ordos was formed after the formation of the secondary reduction. So, paleo-interlayer oxidation zone type uranium mineralization has the mineralization size much greater than the former two. (authors)