A Prediction and Evaluation Method for Sandstone-Type Uranium Deposits in Relatively Tectonic Environments

Abstract

This invention belongs to the technical field of basic uranium geological research, and specifically discloses a method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonic structures. The method includes: step (1) collection and organization of regional geological data; step (2) analysis of basin tectonic geological background and basin tectonic types; step (3) study of typical deposits; step (4) map compilation and study of regional uranium mineralization regularities; and step (5) extraction of prediction elements and prospective prediction. This invention, through the collection and organization of geological data from a geological region, combined with limited regional geological work, fully analyzes the tectonic geological background and metallogenic geological conditions; through the study of typical deposits, it identifies the target layers and key ore-controlling elements for prospecting, summarizes regional uranium mineralization regularities, extracts prediction elements, predicts and delineates favorable mineralization zones, and provides a basis for strategic uranium ore selection and medium- to long-term uranium geological exploration deployment.

Description

Technical Field

[0001] This invention belongs to the technical field of basic uranium geological research, specifically relating to a method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonic structures. Background Technology

[0002] Northwest my country also has several large, medium and small basins, including Badain Jaran, Bayingol, Chaoshui, Jiuquan, Yabulai, Wuteng and Bayanhot. Due to the relatively strong tectonic environment in which these basins are located, the basin base and basin cover have been cut and destroyed to varying degrees by the tectonic structure, and the tectonic environment favorable for mineralization is very limited. In addition, the level of geological exploration and scientific research on uranium deposits in these basins is relatively low, and there have been no new breakthroughs in uranium geological prospecting at present.

[0003] Therefore, it is urgent to conduct uranium deposit prediction and evaluation in these large, medium and small basins developed in the tectonically active regions of northwestern my country, effectively identify the favorable tectonic locations for sandstone-type uranium mineralization in each basin, and then, in combination with the favorable geological conditions for sandstone-type uranium mineralization, delineate uranium mineralization prospective areas, accurately and effectively narrow down the prospecting target area, improve prospecting efficiency, and provide a basis for the selection of reserve bases for sandstone-type uranium deposits, as well as for long-term strategic uranium deposit selection and uranium geological exploration deployment. Summary of the Invention

[0004] The purpose of this invention is to provide a method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonic structures. This method involves collecting and organizing geological data of a geological region, combining it with a small amount of regional geological work, to fully analyze the tectonic geological background and metallogenic geological conditions. Through the study of typical deposits, it identifies the target layers for prospecting and key ore-controlling elements, summarizes the regional uranium metallogenic regularities, extracts predictive elements, predicts and delineates favorable metallogenic sections, and provides a basis for strategic uranium ore selection and medium- and long-term uranium geological exploration deployment.

[0005] Technical solution to achieve the purpose of this invention:

[0006] A method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonic structures, the method comprising the following steps:

[0007] Step (1): Collection and organization of regional geological data;

[0008] Step (2), analysis of the basin's tectonic geological background and tectonic type;

[0009] Step (3): Study of typical mineral deposits;

[0010] Step (4): Map compilation and regional uranium mineralization regularity study;

[0011] Step (5): Extraction of predictive elements and forecasting of future prospects.

[0012] Step (1) includes:

[0013] Step (1.1): Systematically collect geological reports, basic geological maps, and literature completed by various departments within the study area;

[0014] Step (1.2): Summarize, organize and analyze the data to screen for favorable basins or sections for uranium mineralization.

[0015] Step (1.1) specifically involves: comprehensively and systematically collecting basic geological, geophysical and remote sensing, hydrogeological, uranium geology and exploration engineering data within the study area; during the data collection and organization process, emphasis should be placed on various data related to uranium geology and structure, including regional tectonic events, regional tectonic types, regional large faults and regional uranium mineralization information; and the collected data should be merged and comprehensively organized according to type.

[0016] Step (1.2) specifically involves: analyzing the geological environment of the tectonic system and the geological conditions such as the structure, uranium source and hydrology of uranium mineralization, dividing the regional tectonic units, and screening out basins or basin segments that are favorable for mineralization.

[0017] Step (2) includes:

[0018] Step (2.1), Analysis of the tectonic background of uranium mineralization in the basin;

[0019] Step (2.2): Study on the Cenozoic tectonic-sedimentary evolution of the basin;

[0020] Step (2.3), analysis of potential mineralization period tectonic types in the basin.

[0021] Step (2.1) specifically involves: analyzing the geotectonic environment in which the basin is located, dividing the basin into tectonic units based on the tectonic environment and tectonic features, further analyzing the tectonic features of the basin basement and basin cover, exploring the tectonic system, paleogeographic environment, and sedimentary tectonic features of the basin or each tectonic unit within the basin, and analyzing the uranium mineralization tectonic conditions.

[0022] Step (2.2) specifically involves: analyzing the structural characteristics of the basin basement, the structural evolution characteristics of the basin cover layer, and the paleoclimate characteristics of the basin during the Cenozoic sedimentary period; screening out areas with a tectonic background dominated by uplift and subsidence, relatively weak activity, well-developed sand bodies, and conditions for sandstone-type uranium ore transformation; and identifying favorable tectonic regions and favorable stratigraphic positions for mineralization.

[0023] Step (2.3) specifically involves: conducting research on the structural characteristics of the newly formed zones in the basin, utilizing structural profile maps compiled by predecessors, or conducting geological profile measurements and geophysical electromagnetic profile measurements, or compiling borehole-to-well profile maps using previous borehole data, analyzing the stratigraphic structure characteristics, fault structures, and fold structures of the basin, dividing the structural uplift zone and rift burial zone within the basin, analyzing the rift types at different evolution stages of the basin, and further analyzing the basin structural types during the potential uranium mineralization period.

[0024] Step (3) includes:

[0025] Step (3.1): Analyze the uranium mineralization geological conditions of the mining area;

[0026] Step (3.2): Analyze the geological characteristics of the deposit and the characteristics of uranium mineralization;

[0027] Step (3.3): Determine the key mineral control elements.

[0028] The analysis of uranium mineralization geological conditions in step (3.1) includes: analyzing uranium source conditions in the erosion source area and uranium source conditions in the sedimentary caprock of the mining area, tilting structures and fault structures in the mining area, lithological and lithofacies conditions of the prospecting target layer, paleoclimate conditions during the sedimentary evolution period, hydrogeological conditions, and post-alteration alteration conditions of the sand bodies in the prospecting target layer.

[0029] The analysis of the geological characteristics and uranium mineralization characteristics of the deposit in step (3.2) includes: analyzing the geological spatial distribution characteristics, mineralization geochemical characteristics, mineralization geological processes, geological age and geological evolution stages of the deposit; analyzing the characteristics of uranium ore bodies, uranium mineralization types, uranium minerals and associated mineral types and assemblage characteristics, uranium mineralization periods and uranium mineralization ages.

[0030] Step (3.3) specifically involves: analyzing the uranium mineralization geological conditions of the mining area through step (3.1) and the geological spatial distribution characteristics and uranium mineralization characteristics of the deposit through step (3.2), identifying key ore-controlling elements, and establishing a uranium mineralization prediction model.

[0031] Step (4) includes:

[0032] Step (4.1): Compile basic maps at different scales;

[0033] Step (4.2): Conduct research on regional uranium mineralization regularity.

[0034] Step (4.1) specifically involves compiling 1:1,000,000 to 1:500,000 scale uranium geological maps, structural outline maps, target layer sedimentary facies maps, metallogenic element maps, and prediction element maps for the entire study area; 1:250,000 to 1:100,000 scale uranium geological maps, fault structure maps or structural zoning maps, ore-bearing layer sedimentary facies maps, top and bottom plate burial depth maps, sand body isopyrographs, sand content isographs, metallogenic element maps, and prediction element maps for key sections and mining areas of the basin; and 1:50,000 to 1:10,000 scale uranium geological maps, sedimentary facies maps, sand body isopyrographs, sand content maps, epigenetic alteration maps, and metallogenic element maps, etc.

[0035] Step (4.2) specifically involves summarizing regional tectonic zoning, tectonic types, basin types, sedimentary formation types, post-gene alteration types, uranium mineralization types, uranium mineralization types, and uranium mineralization ages; identifying regional uranium mineralization control factors; and establishing regional mineral exploration indicators.

[0036] Step (5) specifically involves: identifying mineral exploration markers in the series of basic maps compiled, extracting and defining various mineral control elements in the study of regional uranium mineralization regularity, delineating favorable mineralization areas using MRAS software and human-machine collaboration, and analyzing favorable mineralization conditions and unfavorable factors in the region.

[0037] The beneficial technical effects of this invention are as follows:

[0038] 1. The present invention provides a method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonic structures. Based on the classification of regional tectonic types, identification of tectonic types during the potential metallogenic period of basins, and research on typical deposits, it can screen out key basins or key sections of basins with relatively weak structures that are conducive to the development of sandstone-type uranium deposits within areas with strong tectonic structures.

[0039] 2. The present invention provides a method for predicting and evaluating sandstone-type uranium deposits in environments with relatively strong tectonics. By compiling a series of maps at different scales and studying regional uranium mineralization patterns, the regional uranium mineralization patterns can be summarized and concluded. Key ore-controlling elements can be identified, defined, and extracted on the maps. This method can quickly and effectively delineate uranium mineralization prospective areas, providing a basis for strategic selection of regional uranium deposits, new reserve exploration bases, and medium- and long-term geological exploration deployment for uranium deposits.

[0040] 3. The sandstone-type uranium deposit prediction and evaluation method provided by this invention in a relatively structurally strong environment can accurately and effectively narrow down the prospecting target area, improve prospecting efficiency, and is highly operable. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments.

[0042] This invention, taking the strategic selection area of ​​sandstone-type uranium deposits in the central and western regions of Gansu and Inner Mongolia as an example, provides a method for predicting and evaluating sandstone-type uranium deposits in a relatively tectonic environment, specifically including the following steps:

[0043] Step (1) Collection and organization of regional geological data

[0044] Step (1.1): Collect geological reports, basic geological maps and literature completed by various departments in the study area.

[0045] Comprehensive and systematic data collection should be conducted on basic geology, geophysics and remote sensing, hydrogeology, uranium geology, and exploration engineering within the study area. During the data collection and processing, emphasis should be placed on data related to uranium geology and tectonics, including regional tectonic events, regional tectonic types, large regional faults, and regional uranium mineralization information. The collected data should be merged and comprehensively organized according to type.

[0046] This project collects exploration geological reports, basic geological plans, cross-sections (geological cross-sections, seismic cross-sections, borehole cross-sections), structural outlines, and literature from various departments specializing in petroleum geology, coalfield geology, hydrogeology, and uranium geology in the central and western parts of Gansu and Inner Mongolia. The collected data is then categorized and synthesized according to type.

[0047] Step (1.2): Summarize, organize and analyze the data to screen for favorable basins or sections for uranium mineralization.

[0048] The collected data were systematically organized, analyzed, and digested. A preliminary analysis was conducted on the tectonic geological environment and geological conditions such as uranium mineralization structure, uranium source, and hydrology. Regional tectonic units were delineated, and basins or basin segments with favorable mineralization were selected.

[0049] Based on the tectonic environment and the distribution and development characteristics of large fault structures in the study area, the region is clearly characterized by north-south segmentation and east-west zonation. The Gansu-Inner Mongolia region is divided into three tectonic zones from north to south: ① Northern tectonic zone: Beishan Basin Group – Badain Jaran Basin – Bayingol Basin; ② Central tectonic zone: Jinta-Huahai Basin – Chaoshui Basin – Yabulai Basin – Bayanhot Basin; ③ Southern tectonic zone: Jiuquan Basin – Minle Basin – Wuteng Basin. According to the regional tectonic geological characteristics, small-to-medium scale tectonic outline maps were first used to screen out sections with relatively weak tectonic activity. Then, within these sections, large-spacing borehole profiles and geophysical and geochemical profiles were used to screen out favorable areas with relatively stable tectonic slopes. Based on the tectonic environment of the basins within each tectonic zone, the southern Bayingol Basin, the northern edge of the Chaoshui Basin, and the northern Yabulai Basin were preliminarily identified as favorable areas for sandstone-type uranium mineralization.

[0050] Step (2): Analysis of the basin's tectonic geological background and tectonic type.

[0051] Step (2.1), Analysis of the tectonic background of uranium mineralization in the basin.

[0052] For the key basin segments selected in step (1), a tectonic background analysis of uranium mineralization in the basin is carried out. The geotectonic environment in which the basin is located is analyzed, and the basin tectonic units are divided according to the tectonic environment and tectonic characteristics. The tectonic characteristics of the basin basement and basin cover are further analyzed, and the tectonic system, paleogeographic environment, and sedimentary tectonic characteristics of the basin or each tectonic unit within the basin are explored. The tectonic conditions for uranium mineralization are analyzed.

[0053] The Bayingobi Basin is situated within the Tianshan-Xingmeng fold system, controlled by the Altyn Tagh and Engelwusu faults. The overall structure trends northeast. Analysis of the basin's cover strata reveals a pattern of alternating faults, depressions, and uplifts. Based on a map of the basement depth of the Cenozoic zone within the basin, it can be divided into one uplift and five depressions, totaling six second-order tectonic units. These can be further subdivided into 13 depressions and 16 uplifts, forming 29 third-order tectonic units. The transitional zones between depressions and uplifts within the depression areas can form favorable tectonic slopes for uranium mineralization.

[0054] Step (2.2): Study on the Cenozoic tectonic-sedimentary evolution of the basin.

[0055] By analyzing the structural characteristics of the basin's basement, the structural evolution of the basin's cover layer, and the paleoclimatic characteristics of the basin's Mesozoic and Cenozoic sedimentary periods, areas with a tectonic background dominated by uplift and subsidence, relatively weak activity, well-developed sand bodies, and conditions for sandstone-type uranium mineralization were selected. Favorable tectonic regions and favorable stratigraphic positions for mineralization were then identified.

[0056] Based on the analysis of the Cenozoic tectonic-sedimentary evolution of the Bayingobi Basin, and according to the angular unconformities developed in the strata, the basin's sedimentary infill sequence, and burial history, the Cenozoic evolution of the basin is divided into six stages: the Early-Middle Jurassic extensional rifting stage, the Late Jurassic intracontinental depression stage, the Early Cretaceous extensional rifting stage, the Late Cretaceous compressional uplift stage, the (Eocene) Oligocene-Miocene piedmont depression stage, and the Pliocene-Pleistocene foreland basin stage. During the Early Cretaceous basin extensional subsidence stage, the organic-rich Bayingobi Formation was formed, which is a favorable target layer for uranium mineralization. The Late Cretaceous to Paleogene period was the main compressional uplift and erosion stage of the basin, a crucial period for uranium mineralization.

[0057] Step (2.3), analysis of potential mineralization period tectonic types in the basin.

[0058] A detailed study of the structural characteristics of the newly formed zones in the basin will be conducted. This will involve making full use of the structural profiles compiled by previous researchers, conducting geological profile measurements and geophysical electromagnetic profile measurements, or compiling borehole-to-well profiles based on previous borehole data. The study will analyze the stratigraphic structure, fault structures, and fold structures of the basin, delineate the structural uplift zone and the burial depth zone within the basin, analyze the burial types at different stages of the basin's evolution, and further analyze the structural types of the basin during the potential uranium mineralization period.

[0059] Step (2.2) analysis shows that the important prospecting target layer in the Bayingobi Basin is the Bayingobi Formation, and the important period of uranium mineralization is from the Late Cretaceous to the Paleogene. The analysis focuses on the various depressions and types within the basin during the Late Cretaceous to Paleogene periods. Through comprehensive analysis of geological structural profiles, seismic profiles, combined electrical and magnetic profiles, and borehole profiles, the 13 depressions in the Bayingobi Basin are divided into single-fault depressions and double-fault depressions. Single-fault depressions can provide favorable structural slope zones for uranium mineralization and are relatively favorable areas for uranium mineralization, while double-fault depressions are unfavorable areas for uranium mineralization.

[0060] Step (3): Study of typical mineral deposits.

[0061] Step (3.1): Analyze the geological conditions of uranium mineralization in the mining area.

[0062] The analysis focuses on the uranium source conditions in the erosion source area and the uranium source conditions in the sedimentary cover layer of the mining area, the tilting and fault structures in the mining area, the lithological and lithofacies conditions of the prospecting target layer, the paleoclimate conditions during the sedimentary evolution period, the hydrogeological conditions, and the post-alteration alteration conditions of the sand bodies in the prospecting target layer.

[0063] Among them, the analysis of uranium source conditions in the erosion source area and uranium source conditions in the sedimentary caprock of the mining area, taking the uranium source conditions in the erosion source area as an example, the research method is as follows: First, determine the location of the erosion source area, then study the lithology exposed in the erosion source area, then analyze the current uranium content of various lithologies and estimate the original uranium content based on the uranium-thorium ratio, calculate the activation migration of uranium, and finally analyze its uranium supply capacity.

[0064] The method for analyzing post-alteration alteration conditions is as follows: First, the color of the primary sand body in the target layer is determined by hand specimens and microscopic mineral analysis. Then, the colors of the post-oxidized and post-reduced altered sand bodies are further confirmed. Finally, the target layer sand body is divided into oxidation zone, reduction zone and transition zone.

[0065] Taking Tamusu as a typical uranium deposit, the study of the uranium mineralization geological conditions in the mining area was carried out first. The mining area is located at the northeastern end of the Yingejing Depression, in the northern part of the Yingejing Depression. To the north of the mining area is Zongnai Mountain, where a large area of ​​Permian-Triassic intermediate-acidic granite is distributed in the source area. The original uranium content is generally 1.93×10-6 to 93.47×10-6, and it has been in a state of weathering and erosion for a long time. The activated uranium migration is (-0.32 to -91.65), with a high uranium leaching rate and obvious uranium migration, which can provide abundant uranium sources for the upper part of the Bayingobi Formation, which is the ore-bearing stratum. The Yingejing Depression is a single fault type, and a stable slope zone is developed in the northeastern part of the depression. The Bayingobi Formation is exposed on the surface. Uranium-bearing oxygenated water can develop interlayer oxidation along the bedding of the Bayingobi Formation, which has the conditions for uranium mineralization and post-alteration alteration. The Bayingobi Formation on the slope zone has a deltaic sedimentary system, in which sand bodies of a certain size are developed in the delta plain and front, which is a favorable space for uranium mineralization.

[0066] Step (3.2): Analyze the geological characteristics and uranium mineralization characteristics of the deposit.

[0067] The study analyzes the geological spatial distribution characteristics, mineralization geochemical characteristics, mineralization geological processes, geological age and geological evolution stages of the ore deposits, as well as the characteristics of uranium ore bodies, uranium mineralization types, uranium minerals and associated mineral types and assemblage characteristics, uranium mineralization periods and uranium mineralization ages.

[0068] The methods for analyzing uranium mineralization types are as follows: Generally, the type of uranium mineralization is determined based on the uranium mineralization process. Sandstone-type uranium mineralization types are mainly divided into sedimentary diagenetic type, phreatic oxidation zone type, interlayer oxidation zone type, and composite genetic type.

[0069] The mining area is located in the northeastern slope zone of the Yinggejing Depression, 13 km from the northern erosion source area. The stable slope zone and its well-developed scale provide ample mineralization opportunities for inter-layer oxidation. The braided deltaic gray sand bodies provide sufficient ore-hosting space and reducing agents for uranium mineralization. The main ore bodies in the Tamusu deposit are mostly platy in shape and relatively large in scale. A small number are lenticular in shape and smaller in scale. The total length of the uranium ore belt is approximately 5800 m, with a maximum width of 1300 m. The ore bodies have a gentle dip, generally 3–5°. The main burial depth is generally 300–530 m, with a single ore body thickness of 0.47–8.96 m, an average thickness of 1.54 m, and a grade of 0.0500%–0.7075%, with an average grade of 0.0990%. The ore type is mainly sandstone, followed by mudstone and migmatite. The main uranium minerals are pitchblende and uranium ore. The main uranium mineralization periods and processes include Early Cretaceous (108.2–117.0 Ma) sedimentary-diagenetic processes, Late Cretaceous (68.9–71.9 Ma) interlayer oxidation, Eocene (44.8–48.0 Ma) hydrothermal superimposed interlayer oxidation, late Miocene (10.4–12.5 Ma) interlayer oxidation, and late Pliocene (2.5–3.3 Ma) superimposed interlayer oxidation.

[0070] Step (3.3): Determine the key mineral control elements.

[0071] Step (3.1) analyzes the uranium source conditions, tectonic conditions, sedimentary facies and sedimentary formation conditions of the target layer, and post-alteration alteration conditions of the sand body in the uranium mineralization area. Then, step (3.2) further analyzes the planar and vertical distribution characteristics of the uranium orebody, the occurrence location and spatial variation characteristics of the orebody. Through the spatial distribution of the uranium orebody and the uranium mineralization characteristics, the type of uranium mineralization is analyzed. Combined with the uranium mineralization conditions in step (3.1), it is determined whether the spatial distribution of the orebody is mainly controlled by uranium source conditions, tectonic conditions, sedimentary facies and sedimentary formation conditions, post-alteration alteration conditions, or a combination of these conditions. Finally, the key controlling factors of the orebody are identified, the uranium mineralization mechanism is elucidated, and a uranium mineralization prediction model is constructed.

[0072] The geological conditions for uranium mineralization in the mining area are analyzed in step (3.1), and the spatial distribution characteristics of the ore deposit are analyzed in step (3.2).

[0073] The uranium mineralization characteristics identified the key ore-controlling elements of the Tamusu deposit as the Zongnaishan uranium source elements, the northeastern slope zone elements of the Yinggejing Depression, the stable sand body elements and reducing agent elements of the braided delta sedimentary sand bodies of the Bayingobi Formation, the sedimentary uranium pre-enrichment elements, and the interlayer oxidation developed in the slope zone.

[0074] Step (4): Map compilation and regional uranium mineralization regularity study.

[0075] Step (4.1): Compile basic maps of different scales.

[0076] The entire study area can be mapped with 1:1,000,000 to 1:500,000 scale uranium geological maps, structural outline maps, target layer sedimentary facies maps, metallogenic element maps, and prediction element maps. The basin can be mapped with 1:250,000 to 1:100,000 scale uranium geological maps, fault structure maps or structural zoning maps, ore-bearing layer sedimentary facies maps, top and bottom plate burial depth maps, sand body isopyrographs, sand content isographs, metallogenic element maps, and prediction element maps. Key sections and mining areas of the basin can be mapped with 1:50,000 to 1:10,000 scale uranium geological maps, sedimentary facies maps, sand body isopyrographs, sand content maps, epigenetic alteration maps, and metallogenic element maps.

[0077] For the central and western regions of Gansu and Inner Mongolia, we will compile 1:1,000,000 uranium geological maps, structural outline maps, Mesozoic and Cenozoic bottom depth maps, target layer sedimentary facies maps, metallogenic element maps, and prediction element maps. For each key basin, we will compile 1:250,000 uranium geological maps, fault structure maps or structural zoning maps, ore-bearing layer sedimentary facies maps, top and bottom plate depth maps, sand body isopyrographs, sand content isographs, metallogenic element maps, and prediction element maps. For key areas of mining areas or basins, we will compile a series of maps including 1:50,000 uranium geological maps, sedimentary facies maps, sand body isopyrographs, sand content maps, epigenetic alteration maps, and metallogenic element maps. We will also compile 1:10,000 geological profile maps and seismic profile maps, and 1:5,000 borehole-to-well profile maps.

[0078] Step (4.2): Conduct research on regional uranium mineralization regularity.

[0079] This study summarizes regional tectonic zoning, tectonic types, basin types, sedimentary formation types, post-gene alteration types, uranium mineralization types, uranium mineralization types, and uranium mineralization epochs, identifies regional uranium mineralization controlling factors, and establishes regional mineral exploration indicators.

[0080] First, based on regional tectonic zoning, tectonic types, and basin types, favorable tectonic basins for uranium mineralization are selected. Within these selected favorable tectonic basins, studies are conducted on the sedimentary formation characteristics of the target layer, the post-alteration characteristics of sand bodies, the uranium mineralization age, and the corresponding uranium mineralization processes. Combined with previous studies on tectonic features, a tectonic-sedimentary-uranium mineralization evolution system for the target layer in the study area is jointly constructed. Under this system, uranium mineralization conditions and processes are analyzed, thereby identifying the controlling factors of regional uranium mineralization.

[0081] By summarizing the regional tectonic types and distribution characteristics, basin tectonic types and target layer sedimentary formation characteristics and post-alteration alteration characteristics, and regional uranium mineralization types, uranium mineralization types and mineralization patterns, the following conclusions were drawn regarding uranium mineralization patterns in the central and western parts of Gansu and Inner Mongolia: ① The ore-bearing strata are controlled by the spatiotemporal-tectonic environment; ② There are numerous basins in the region, but the favorable space for mineralization is limited, and the favorable space for uranium mineralization is controlled by single-fault depressions or troughs; ③ Each basin is dominated by fan delta-lacustrine sedimentary deposits and lacks fluvial sedimentary environments, so uranium mineralization is mainly located on one side of the slope of a single-fault depression; ④ There is abundant uranium mineralization information in the region, but the ore bodies are small in scale and low in grade, and uranium mineralization is biased towards sedimentary-diagenetic processes, with large deposits only possible in areas with developed inter-layer oxidation. The development of single-faulted depressions and basin slope zones on one side is a favorable tectonic environment for regional uranium mineralization. The development of thick sand bodies in braided river delta plains and their front edges is a favorable sedimentary facies for uranium mineralization. The post-oxidation alteration of sand bodies is a favorable alteration for uranium mineralization.

[0082] Step (5): Extraction of predictive elements and forecasting of future prospects.

[0083] In the series of basic maps compiled, mineral exploration indicators were identified, and various ore-controlling elements were determined in the study of regional uranium mineralization regularity. MRAS software and human-machine collaboration were used to delineate favorable mineralization areas, and the favorable mineralization conditions and unfavorable factors in the region were analyzed.

[0084] Based on the regional uranium mineralization regularity defined in step (4.2) and the established mineral exploration identification markers, key mineralization control elements were identified and extracted from a series of basic maps at different scales compiled in step (4.1). Then, favorable mineralization areas were delineated using MRAS software and human-machine collaboration. Finally, one mineral exploration target area was delineated in the Bayingobi Basin, and two secondary uranium mineralization prospective areas and two tertiary uranium mineralization prospective areas were predicted. The prediction basis for each prospective area and the favorable geological conditions and unfavorable factors for uranium mineralization were fully analyzed, providing a basis for strategic uranium ore selection and medium- and long-term uranium geological exploration.

[0085] It should be noted that this invention is not limited to the above examples. For example, during the strategic area selection process, further research can be conducted in the Chaoshui Basin, Yabulai Basin, and Bayinhot Basin on basin tectonic-sedimentary evolution, basin tectonic type classification, basic map compilation, typical deposit research, and regional uranium metallogenic regularity summary. This will help to identify key ore-controlling elements in each basin, identify and extract each element, predict and select promising uranium metallogenic areas, and provide a basis for strategic area selection and medium- and long-term uranium geological exploration of sandstone-type uranium deposits in Northwest my country.

[0086] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. All contents not described in detail in the present invention can be derived from existing technologies.

Claims

1. A method for constructing a prediction and evaluation of sandstone-type uranium deposits in a relatively strong environment, characterized by, The method includes the following steps: Step (1): Collection and organization of regional geological data; Step (2): Analysis of the basin's tectonic geological background and tectonic type; Step (3): Study of typical mineral deposits; Step (4): Map compilation and regional uranium mineralization regularity study; Step (5): Extraction of predictive elements and forecasting of future prospects; Step (1) includes: First, small-to-medium scale structural outline maps are used to screen out sections with relatively weak tectonic activity; then, within these sections, large-spacing borehole profile maps and geophysical and geochemical profile maps are used to screen out favorable sections where relatively stable tectonic slopes have developed in the basin. Step (2) includes: Step (2.1): For the key basin segments selected in step (1), conduct a tectonic background analysis of uranium mineralization in the basins. Based on the tectonic environment and tectonic features, the basin is divided into tectonic units. The structural features of the basin basement and basin cover are further analyzed. The tectonic system, paleogeographic environment, and sedimentary structural features of the basin or each tectonic unit within the basin are explored. The tectonic conditions for uranium mineralization are analyzed. The depression and uplift transition zone developed in the depression area forms a tectonic slope zone that is favorable for uranium mineralization. Step (2.2), Cenozoic tectonic-sedimentary evolution study of the basin: By analyzing the structural characteristics of the basin's basement, the structural evolution characteristics of the basin's cover layer, and the paleoclimatic characteristics of the basin's Mesozoic and Cenozoic sedimentary periods, areas with a tectonic background dominated by uplift and subsidence, relatively weak activity, well-developed sand bodies, and conditions for sandstone-type uranium ore alteration were selected, and favorable tectonic regions and favorable stratigraphic positions for mineralization were identified. Step (2.3), Analysis of potential mineralization tectonic types in the basin: Research on the structural characteristics of the Cenozoic zone in the basin will be conducted. This will involve using existing structural profiles, geological and geophysical electromagnetic profiling, or borehole data to create a series of borehole profiles. The study will analyze the basin's stratigraphic structure, fault structures, and fold structures, delineating the basin's tectonic uplift and rift depth zones. It will also analyze the types of rifts at different stages of the basin's evolution, and further analyze the basin's structural types during potential uranium mineralization periods. Single-fault depressions are considered relatively favorable areas for uranium mineralization, while double-fault depressions are considered unfavorable areas. Step (3) includes: Step (3.1): Analyze the uranium mineralization geological conditions of the mining area: The analysis included the uranium source conditions in the erosion source area and the uranium source conditions in the sedimentary cover layer of the mining area, the tilting and fault structures in the mining area, the lithological and lithofacies conditions of the prospecting target layer, the paleoclimate conditions during the sedimentary evolution period, the hydrogeological conditions, and the post-alteration alteration conditions of the sand bodies in the prospecting target layer. Step (3.2): Analyze the geological characteristics of the deposit and the characteristics of uranium mineralization: The geological spatial distribution characteristics, metallogenic geochemical characteristics, metallogenic geological processes, geological age and geological evolution stages of the ore deposits are analyzed. The characteristics of uranium ore bodies, uranium mineralization types, uranium minerals and associated mineral types and assemblage characteristics, uranium mineralization periods and uranium mineralization ages are also analyzed. Step (3.3): Determine key ore-controlling factors: By analyzing the uranium mineralization geological conditions of the mining area in step (3.1) and the geological spatial distribution characteristics and uranium mineralization characteristics of the deposit in step (3.2), the key ore-controlling elements are identified, and a uranium mineralization prediction model is established.

2. The method according to claim 1, wherein the method is characterized by, Step (1) further includes: Step (1.1): Collect data completed by various departments within the study area, including geological reports, basic geological maps, and literature; Step (1.2): Summarize, organize and analyze the data to screen for favorable basins or sections for uranium mineralization.

3. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 2, characterized in that, The specific steps (1.1) are as follows: comprehensively and systematically collect basic geological, geophysical and remote sensing, hydrogeological, uranium geology and exploration engineering data in the study area; in the process of data collection and organization, the focus should be on various data related to uranium geology and structure, including regional tectonic events, regional tectonic types, regional large faults and regional uranium mineralization information; and the collected data should be merged and comprehensively organized according to type.

4. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 3, characterized in that, The specific steps (1.2) are as follows: analyze geological conditions, including the tectonic geological environment and the structure, uranium source and hydrology of uranium mineralization, divide regional tectonic units, and screen out basins or basin segments with favorable mineralization.

5. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 1, characterized in that, Step (4) includes: Step (4.1): Compile basic maps at different scales; Step (4.2): Conduct research on regional uranium mineralization regularity.

6. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 5, characterized in that, The specific steps (4.1) are as follows: For the entire study area, compile 1:1,000,000 to 1:500,000 uranium geological maps, structural outline maps, target layer sedimentary facies maps, metallogenic element maps, and prediction element maps; for the basin, compile 1:250,000 to 1:100,000 uranium geological maps, fault structure maps or structural zoning maps, ore-bearing layer sedimentary facies maps, top and bottom plate burial depth maps, sand body isopyrographs, sand content isographs, metallogenic element maps, and prediction element maps; for key sections and mining areas of the basin, compile a series of maps including 1:50,000 to 1:10,000 uranium geological maps, sedimentary facies maps, sand body isopyrographs, sand content maps, epigenetic alteration maps, and metallogenic element maps.

7. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 6, characterized in that, The specific steps (4.2) are as follows: Summarize the regional tectonic zoning, tectonic types, basin types, sedimentary formation types, post-gene alteration types, uranium mineralization types, uranium mineralization types and uranium mineralization ages, determine the regional uranium mineralization control factors, and establish regional mineral exploration indicators.

8. The method for predicting and evaluating sandstone-type uranium deposits in a relatively structurally strong environment according to claim 7, characterized in that, The specific steps (5) are as follows: in the series of basic maps compiled, identify mineral exploration signs, extract and define various mineral control elements in the study of regional uranium mineralization regularity, delineate favorable mineralization areas using MRAS software and human-machine collaboration, and analyze the favorable mineralization conditions and unfavorable factors in the region.