An evaluation method suitable for sandstone type uranium ore prospecting target layer

Abstract

The present application belongs to the field of basin sandstone type uranium ore prospecting technology method, discloses a kind of evaluation method suitable for sandstone type uranium ore prospecting target layer, comprising: the determination of prospecting target layer in basin uranium exploration area;The lithology geochemistry zoning of target layer is carried out;Target layer sandstone-mudstone is equidistantly continuously grooving, and sandstone sample and mudstone sample are collected;The sandstone sample collected is mechanically broken and sieved, and sandstone fine grain component is obtained;Sandstone fine grain component and mudstone sample are tested and analyzed, and test analysis result is obtained;According to test analysis result, target layer uranium mineralization environment and potential evaluation are carried out.The sample collected by the method is more representative and contrastive, and test data can comprehensively and accurately reflect the real geological and geochemical characteristics of target layer, prevent misjudgment or miss effective target layer, and scientifically evaluate the uranium mineralization environment and potential of prospecting target layer in working area.

Description

Technical Field

[0001] This invention belongs to the field of sandstone-type uranium exploration technology and methods in basins, specifically involving an evaluation method for target layers in sandstone-type uranium exploration. Background Technology

[0002] In the early stages of the investigation and evaluation of sandstone-type uranium resources in sedimentary basins, it is necessary to comprehensively evaluate the elemental, mineral, and geochemical characteristics of rocks within different geochemical zones of the target stratum, thereby objectively assessing its uranium mineralization potential. Among these factors, the appropriate collection and representativeness of rock samples from different geochemical zones directly affect the scientific evaluation of the mineralization prospects of the target stratum and the prediction of favorable prospective areas.

[0003] In the past, uranium geologists typically used selective sampling or core-splitting methods to collect sandstone samples from different geochemical zones within the target layer, followed by direct whole-rock testing and evaluation. However, the representativeness of the data obtained in this way is somewhat lacking, which significantly impacts the evaluation of its mineralization potential. For example, if the sample is collected in a zone where carbonaceous debris or pyrite is highly developed, its organic carbon or total sulfur content will be extremely high, leading to the conclusion that the target layer has a high reducing capacity. Conversely, it may be extremely low, indicating a weak reducing capacity. This may not fully and reasonably represent the true geochemical characteristics of the stratum. Furthermore, the test results for different grain sizes of sandstone within the target layer (coarse-grained, medium-grained, and fine-grained) also vary considerably, resulting in poor comparability. Meanwhile, the flow-rock reaction intensity during the later mineralization process in the shallow (semi-)open system of the ore-bearing strata is mostly at the clay level, generally only causing changes in the fine-grained matrix composition of sandstone. The main components of sandstone itself, such as quartz, feldspar, and various rock fragments, often mask these subtle changes in geochemical content, interfering with the reasonable evaluation of the characteristics and degree of later fluid alteration, thus making it impossible to accurately detect possible fluid-induced alteration and uranium mineralization. In addition, in the past, geologists mostly collected sandstone samples that are easily altered by later fluids, without paying attention to the collection and analysis of mudstone samples in the target layer, which may affect the accurate identification of the primary geochemical characteristics of the target layer.

[0004] Therefore, all of the above factors will affect the accurate and objective evaluation of the uranium mineralization potential of the entire target stratum in the uranium exploration area to varying degrees, which may lead to misjudgment or omission of effective target strata.

[0005] Currently, no literature has been published or patents have been applied for methods for sample collection from target layers in sandstone-type uranium deposits in basins for different research purposes. General sample collection mainly draws upon and adopts traditional geological sampling techniques and methods. However, these methods do not comprehensively consider the mineralization regularities and basic characteristics of sandstone uranium, and still have some problems and shortcomings in their applicability to sample collection from target layers in the early stages of sandstone-type uranium deposit investigation and evaluation. Summary of the Invention

[0006] The purpose of this invention is to provide an evaluation method for target layers in sandstone-type uranium deposits. Based on the mineralization regularity and geochemical zoning characteristics of sandstone-type uranium deposits, this method provides a process for evaluating the mineralization environment and potential of target layers in the uranium resource survey and evaluation stage of a basin. This process involves collecting and processing sandstone-mudstone samples from target layers at equal intervals in zoning and segmentation, and then evaluating the mineralization environment and potential based on conventional chemical analysis results. The obtained sample data can comprehensively represent the geological and geochemical characteristics of the target layer, and the obtained test data is conducive to comparative analysis. This method can be used accurately and truthfully for the objective evaluation of the uranium mineralization potential and prospecting prospects of the target layer, and can reasonably guide the mineralization deployment.

[0007] Technical solution to achieve the purpose of this invention:

[0008] An evaluation method for target layers in sandstone-type uranium deposit exploration, the method comprising the following steps:

[0009] Step (1): Determination of the target strata within the uranium exploration area of ​​the basin;

[0010] Step (2): Lithological geochemical zoning of the target layer of sandstone and mudstone;

[0011] Step (3): Perform equidistant continuous grooves on sandstone and mudstone in different geochemical zones of the target layer, and collect sandstone and mudstone samples;

[0012] Step (4): Mechanically crush and screen the collected sandstone samples to obtain fine-grained sandstone components;

[0013] Step (5): Test and analyze the fine-grained components of sandstone and mudstone samples to obtain the test and analysis results;

[0014] Step (6): Evaluate the uranium mineralization environment and potential of the target layer based on the test and analysis results.

[0015] Step (1) is as follows: Based on the analysis of the mineralization environment in the basin area, the target stratum for sandstone-type uranium deposits is determined in the uranium exploration area. It is required that there be boreholes in the area that expose the stratum and that there are corresponding rock samples.

[0016] Step (2) includes:

[0017] Step (2.1): The target layer is segmented by lithology, into sandstone and mudstone.

[0018] Step (2.2): Color segmentation of sandstone and mudstone in the target layer.

[0019] Step (3) includes:

[0020] Step (3.1): Continuously groove the sandstone in the target layer after color segmentation, and collect sandstone of all grain sizes for each color segment according to the sample number requirements;

[0021] Step (3.2): Continuously groove the mudstone after color segmentation in the target layer, and collect mudstone for each color segment according to the sample number requirement.

[0022] Step (4) involves setting a grain size threshold based on the size of the target layer's debris particles, mechanically crushing the collected sandstone samples into coarse-grained and fine-grained components, and retaining the fine-grained component of the sandstone.

[0023] Step (5) includes:

[0024] Step (5.1): Crush the fine-grained sandstone components and mudstone samples into powder samples;

[0025] Step (5.2): Selective mineral, elemental and environmental geochemical analysis of the powder sample.

[0026] The chemical analysis in step (5.2) includes: major and minor analysis, quantitative clay X diffraction analysis, organic carbon analysis, total sulfur analysis, redox potential analysis, pH analysis, and acid hydrolysis hydrocarbon analysis.

[0027] Step (6) includes:

[0028] Step (6.1): Evaluate the post-harvest uranium enrichment capability of the target layer based on environmental geochemical indicators;

[0029] Step (6.2): ​​Based on the comparative analysis of geochemical indicators of sandstones of different colors, determine the characteristics and intensity of post-oxidation or secondary reduction in the target layer;

[0030] Step (6.3): Based on the comparative analysis of geochemical indicators of sandstone and mudstone, comprehensively evaluate the uranium mineralization environment, mineralization potential, and scale of the sandstone in the target mineralization layer of the survey area.

[0031] The beneficial technical effects of this invention are as follows:

[0032] 1. The present invention provides an evaluation method for target layers of sandstone-type uranium deposits. Based on the mineralization characteristics of sandstone-type uranium deposits and typical rock geochemical zoning patterns, the method involves continuously grooving and collecting sandstone and mudstone samples in zonal segments. This method overcomes the limitations of the past method, which only collected sandstone of a certain grain size in the target layer. It is not only more representative, but also saves the cost of collecting and testing a large number of samples in the early stage.

[0033] 2. The present invention provides an evaluation method for target layers in sandstone-type uranium deposit exploration, which involves mechanically crushing and screening each particle size of mixed sandstone sample to remove coarse-grained components, effectively reducing the influence of the parent rock's own clastic minerals on the results of post-alteration analysis.

[0034] 3. The present invention provides an evaluation method for target layers in sandstone-type uranium deposits. Chemical testing is performed on the fine-grained components in the sandstone and the mudstone. The test data obtained in this way can comprehensively and accurately reflect the real uranium mineralization environment of the target layer, prevent misjudgment or omission of effective target layers, indicate the correct direction of mineral exploration, and directly serve the actual production needs. It has important value for promotion and application.

[0035] 4. The present invention provides an evaluation method for target layers in sandstone-type uranium deposits, which provides uranium geologists with a method for the rational collection, processing and evaluation of rock samples required for laboratory chemical analysis during sandstone uranium deposit exploration, thereby objectively evaluating the mineralization environment and potential of the target layers. Attached Figure Description

[0036] Figure 1 The present invention provides a flowchart of an evaluation method for target layers in sandstone-type uranium deposit exploration;

[0037] Figure 2 This invention provides a lithological geochemical zoning and sample distribution map of the target layer of the Yaojia Formation in borehole SL1 in the southern Songliao Basin. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0039] like Figure 1 As shown, taking the Kailu Depression in the southwestern part of the Songliao Basin as the research object, this paper presents an evaluation method suitable for sandstone-type uranium deposit exploration target layers, which specifically includes the following steps:

[0040] Step (1) Determination of Target Geological Layers in the Uranium Exploration Area of ​​the Basin

[0041] Step (1.1): Select a mineral exploration site in a sedimentary basin as the research object;

[0042] Step (1.2): Identify the main prospecting target layers in the uranium ore survey area. The target layers should be exposed by boreholes and rock samples should be collected.

[0043] For example, the Kailu Depression in the southwestern part of the Songliao Basin was selected as the research object, the Yaojia Formation of the Upper Cretaceous was selected as the target layer for mineral exploration, and the Yaojia Formation was exposed by the SL1 borehole.

[0044] Step (2): Select the boreholes that exposed the target layer in step (1) above, and perform lithological geochemical zoning on the sandstone and mudstone of the target layer, that is, lithological and color segmentation.

[0045] Step (2.1): Based on the target mineral exploration layer determined in step (1) above, the target layer in the borehole is divided into sections from top to bottom according to the two lithologies of sandstone and mudstone.

[0046] Step (2.2): According to step (2.1), the sandstone and mudstone in the target layer are segmented by color respectively;

[0047] The sandstone zones are designated from top to bottom according to their color as: Sd1, Sd2, Sd3, ..., Sd n The lithology includes sandstone of different grain sizes, such as coarse-grained, medium-grained, and fine-grained; the mudstone zones are designated by color from top to bottom as: Md1, Md2, Md3, ..., Md m Where n and m are the total number of sandstone and mudstone segments of different colors, respectively; when the thickness of a thin lithological segment is less than 1m and there are similar segments in other locations in the target layer, the segment can be ignored or merged into the adjacent segment, otherwise it is a separate segment.

[0048] For example, the target mineral exploration layer of the Yaojia Formation in the SL1 borehole of the Kailu Depression is buried at a depth of 461.5m-596.59m. Figure 2As shown, the sandstone can be divided into 5 sections from top to bottom: Sd1 (red sandstone), Sd2 (gray sandstone), Sd3 (red sandstone), Sd4 (gray sandstone), and Sd5 (red sandstone), with approximate burial depths of 462m-474m, 474m-495m, 495m-561m, 561m-565m, and 565m-596.59m, respectively. The mudstone can be divided into 7 sections from top to bottom: Md1, Md2, Md3, Md4, Md5, Md6, and Md7, with approximate burial depths of 461.5m-500m, 500m-502m, 502m-534m, 534m-537.2m, 537.2m-561m, 561m-568m, and 568m-585m, respectively. Thin lithological sections with different geochemical properties (generally less than 1m) within each lithological section were selectively discarded and merged. For example, in the Sd1 red sandstone section, the gray coarse sandstone with a burial depth of 472.4m-473.4m and a thickness of 1m was incorporated into the adjacent lower gray sandstone Sd2 section; while the red coarse sandstone with a burial depth of 564.8m-565.4m and a thickness of 0.6m in the gray sandstone Sd4 section was discarded.

[0049] Step (3): For the prospecting target layer divided into lithological geochemical zones in step (2) above, perform equidistant grooves between sandstone and mudstone within different geochemical zones, and collect sandstone and mudstone samples.

[0050] Step (3.1): Based on the different colored sandstone sections subdivided in step (2) above, uranium geologists, according to actual needs, further subdivided each section (Sd... n ) Collect a certain number of mixed samples of sandstone of different colors and grain sizes by continuously grooved cutting, with at least one sample collected from each section; that is, first, collect a certain Sd n The sample collection process involves dividing the sandstone into smaller, equally spaced segments based on the actual required sample quantity. Then, within each smaller segment, continuous grooves are made at equal intervals to collect sandstone of all grain sizes. Sandstone of different grain sizes within the same smaller segment is continuously grooved and mixed to form a single sandstone sample. Finally, the samples are sequentially registered as S1, S2, S3, ..., S... a Where a is the number of sandstone samples.

[0051] Step (3.2): Based on the different colored mudstone sections subdivided in step (2) above, uranium geologists, according to actual needs, further subdivided the mudstone sections (Md) in each section. m ) Collect a certain number of mudstone samples of different colors by continuously grooved cutting, with at least one sample collected from each section; that is, first, collect samples from a certain Md section. m The section was divided into secondary sub-segments at equal intervals according to the required number of samples. Then, mudstone samples were continuously collected by grooves at equal intervals from each secondary sub-segment, and were sequentially registered as M1, M2, M3, ..., M bb represents the number of mudstone samples.

[0052] For example, the sampling of Yaojia Formation sandstone from borehole SL1 in the Kailu Depression in the southern Songliao Basin is as follows: Figure 2 As shown, the Sd1 section has a burial depth of 462m-474m, with a sandstone thickness of 10.2m. Two samples are planned to be collected. Therefore, the groove thickness of the S1 and S2 samples in this lithological section is 5.1m, and the sampling burial depths are approximately 462m-468m and 468m-474m, respectively. Similarly, three samples are planned to be collected from the gray sandstone Sd2 section, which has a burial depth of 474m-495m and a thickness of 18.1m. The groove thickness of each sample is about 6m. Therefore, the depths of the collected S3, S4, and S5 samples are approximately 474m-481m, 481m-489m, and 489m-495m, respectively. And so on. A total of 11 samples were collected in the five sandstone sections, which can basically cover all the sandstone in the entire Yaojia Formation prospecting target layer in the borehole.

[0053] Meanwhile, it is planned to collect one sample from each of the seven mudstone sections, and the sample numbers are M1, M2, M3, M4, M5, M6 and M7 respectively. Their burial depth and depth are shown in Table 1. Since the mudstone has poor porosity and permeability and is weakly or not affected by later fluid alteration, they can fully represent the original geological and geochemical characteristics of the target layer of Yaojia Formation.

[0054] Table 1. Test results of sandstone-mudstone samples from the target layer of Yaojia Formation in borehole SL1, southern Songliao Basin.

[0055]

[0056]

[0057] Note: The target layer of Yaojia Formation is buried at a depth of 461.5m-596.59m.

[0058] Step (4): Mechanically crush and screen the sandstone samples collected in step (3) to retain the fine-grained components of the sandstone.

[0059] Based on the sandstone samples collected in step (3.1) above, artificial mechanical crushing was first performed indoors. Then, according to the size of the debris particles in the target layer, a grain size threshold was set, and each sample was divided into a coarse-grained component larger than the grain size threshold and a fine-grained component smaller than the grain size threshold. The coarse-grained portion was discarded, and the corresponding fine-grained components were retained for subsequent testing, and were numbered S1', S2', S3', ..., S... a '.

[0060] For example, the sandstone from the 11 Yaojia Formation samples in borehole SL1 within the area was divided into two groups based on a grain size threshold of 120 mesh. The coarse-grained portion of the sandstone with a grain size greater than 120 mesh was removed, and the fine-grained component with a grain size less than 120 mesh was retained. These were numbered S1', S2', S3', S4', S5', S6', S7', S8', S9', and S1'. 10 ', S 11 ', so that it can be used for subsequent testing.

[0061] Step (5): Test and analyze the fine-grained components of the sandstone from step (4) and the mudstone samples from step (3).

[0062] Step (5.1), based on the sandstone fine-grained component sample (S) from step (4) above. a The mudstone samples (M) collected in step (3.2) and the mudstone samples collected in step (3.2) b First, the samples are crushed into 200-mesh powder samples; then the powder samples are divided into several portions according to different test items, and the weight of each portion of the sample must meet the corresponding test requirements.

[0063] Step (5.2): Send the corresponding samples to the laboratory for selective mineral, elemental and environmental geochemical analysis. The total analysis items include: major and trace analysis, clay X-ray quantitative diffraction analysis, organic carbon analysis, total sulfur analysis, redox potential analysis, pH value analysis and acid hydrolysis hydrocarbon analysis, and obtain the corresponding test results. In this way, the geological and geochemical characteristics of the entire target layer can be fully represented, and the samples are all fine-grained components, which facilitates subsequent comparative analysis and accurately reflects the epigenetic alteration characteristics and intensity of the target layer.

[0064] For example, 11 sandstone fine-grained components and 7 mudstone samples from the Yaojia Formation in borehole SL1 of the Kailu Depression in southwestern Songliao Basin were first crushed to 200 mesh. Each sample was then divided into three parts and sent to the corresponding laboratories for major and trace element analysis and organic carbon analysis (C). 有 ) and total sulfur (S) 全 The test obtained elemental and environmental geochemical data of the entire Yaojia Formation target layer, and the results are shown in Table 1.

[0065] Step (6): Based on the test results obtained in step (5) above, evaluate the uranium mineralization geological and geochemical environment and potential of the target layer.

[0066] Based on the analytical and testing data of fine-grained sandstone and mudstone obtained in step (5.2) above, uranium geologists, grounded in the mineralization regularity of sandstone-type uranium deposits in basins, conduct a comprehensive comparative analysis of the changes in mineralogical, elemental content, and environmental geochemical indicators of sandstone and mudstone in different color zones, starting from the characteristics, regularities, and models of sandstone uranium mineralization. This leads to a scientific evaluation of the uranium mineralization geological and geochemical environment and mineralization potential of the target uranium layer in the survey area. Specific steps include:

[0067] Step (6.1): Evaluate the pre-enrichment intensity and inherent uranium content of the target layer based on the uranium content of the fine-grained components of the primary gray mudstone and gray sandstone; determine the primary aquatic environment of the target layer based on the differences and characteristics of their clay mineral content; and determine the environmental geochemical indicators (C) between the two layers. 有 S 全 (e.g., Eh, etc.) to evaluate the post-polymerization capability of the target layer.

[0068] Step (6.2): ​​Based on the comprehensive comparison results of the differences in mineralogical, elemental and environmental geochemical characteristics between the primary gray sandstone and mudstone samples and the (red, yellow) warm-toned sandstone fine-grained component samples and the (gray, light gray, grayish-white, grayish-green, green) cool-toned sandstone fine-grained component samples in Step (6.1), determine the characteristics and intensity of the post-oxidation or secondary reduction of the target layer.

[0069] Step (6.3): Based on the geological and geochemical characteristics and differences of sandstone-mudstone samples of different colors in steps (6.1) and (6.2) above, comprehensively evaluate the uranium mineralization environment, mineralization potential, and scale of the sandstone in the target mineralization layer of the survey area.

[0070] For example, the analysis of sample test results from borehole SL1 of the Yaojia Formation in the Kailu Depression of southwestern Songliao Basin is as follows: Table 1 shows that, combined with the test results of fine-grained components S3', S4', S5', and S9' of gray sandstone and M2, M4, and M6 of gray mudstone, the primary gray rocks of the Yaojia Formation have a high uranium content, ranging from 2.77 ppm to 30.2 ppm, indicating a strong pre-enrichment effect of uranium from syn-sedimentary diagenesis. Their organic carbon and total sulfur are moderately low, at 0.029%-0.714% and <0.003%-0.131%, respectively, indicating their inherent uranium accumulation capacity. Generally, especially sandstone, has low organic carbon content and low reducing capacity. Therefore, our results differ from previous findings that, based on the observation that organic carbon in local carbonaceous rocks could reach 1%, the target layer itself had strong reducing capacity. Our sampling method involved continuous rock sampling within the same lithological geochemical zone, resulting in more reliable results. This aligns with the geological fact that the Yaojia Formation is a weakly reducing reddish-brown variegated formation formed under arid and hot paleoclimate conditions. This suggests that later mineralization in the Yaojia Formation may have required external reducing agents, and that the seepage of deep reducing fluids is an important indicator for mineral exploration in this area. The very low uranium content (2.74ppm-4.42ppm), organic carbon content (0.044%-0.161%), and total sulfur content (all less than 0.003%) in the primary red mudstone samples M1, M3, M5, and M7 also indicate that the target layer belongs to a set of reddish-brown, weakly reducing sedimentary formations.

[0071] The fine-grained components of the Yaojia Formation red sandstone are S1', S2', S6', S7', S8', and S... 10 ', S 11 The very low test results (Table 1) of uranium content (1.72ppm-3.76ppm), organic carbon content (0.012%-0.088%), and total sulfur content (all less than 0.003%) in the sandstone of this area reflect that the sandstone has undergone strong post-oxidation transformation, and the uranium leaching loss in the sand body is severe. Large-scale uranium precipitation and enrichment may occur in other parts, which can be indirectly verified by the discovery of the Qianjiadian super-large uranium ore field in the study area. At the same time, it also reflects that there is a very favorable uranium mineralization potential and prospecting prospects in the Yaojia Formation of the southwestern uranium ore survey area of ​​the Songliao Basin, which is worthy of further exploration.

[0072] This invention can be widely used in the exploration and evaluation of sandstone-type uranium deposits in Mesozoic and Cenozoic sedimentary basins both domestically and internationally. The samples collected and the data obtained from the tests provided by this invention can comprehensively and accurately reflect the geological and geochemical characteristics and metallogenic environment of the target strata in the uranium exploration area. It provides accurate data reference for objectively evaluating the mineralization potential and scale of sandstone uranium, directly serving the needs of mineral exploration deployment, and has important practical application and promotion value.

[0073] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art 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 evaluating target layers in sandstone-type uranium deposit exploration, characterized in that, The method includes the following steps: Step (1): Determination of the target strata for uranium exploration in the basin; Step (2): Lithological geochemical zoning of the target layer of sandstone and mudstone; Step (3): Perform equidistant continuous grooves on sandstone and mudstone within different geochemical zones of the target layer, and collect sandstone and mudstone samples; Step (4): Mechanically crush and screen the collected sandstone samples to obtain fine-grained sandstone components; Step (5): Test and analyze the fine-grained components of sandstone and mudstone samples to obtain the test and analysis results; Step (6): Evaluate the uranium mineralization environment and potential of the target layer based on the test and analysis results; Step (4) is as follows: set a particle size threshold according to the size of the target layer debris particles, mechanically crush the collected sandstone sample and divide it into coarse-grained components and fine-grained components, and retain the fine-grained components of the sandstone.

2. The evaluation method for target layers in sandstone-type uranium deposits according to claim 1, characterized in that, The step (1) is as follows: Based on the analysis of the mineralization environment in the basin area, the target stratum for sandstone-type uranium deposits is determined in the uranium exploration area. It is required that there be boreholes in the area that expose the stratum and that there are corresponding rock samples.

3. The evaluation method for target layers in sandstone-type uranium deposits according to claim 2, characterized in that, Step (2) includes: Step (2.1): Divide the target layer into lithological segments based on sandstone and mudstone; Step (2.2): Color segmentation of sandstone and mudstone in the target layer.

4. The evaluation method for target layers in sandstone-type uranium deposits according to claim 3, characterized in that, Step (3) includes: Step (3.1): Continuously groove the sandstone after color segmentation in the target layer, and collect sandstone of all grain sizes for each color segment according to the sample number requirements; Step (3.2): Continuously groove the mudstone after color segmentation in the target layer, and collect mudstone for each color segment according to the sample number requirement.

5. The evaluation method for target layers in sandstone-type uranium deposits according to claim 4, characterized in that, Step (5) includes: Step (5.1): Crush the fine-grained sandstone components and mudstone samples into powder samples; Step (5.2): Selective mineral, elemental and environmental geochemical analysis of the powder sample.

6. The evaluation method for target layers in sandstone-type uranium deposits according to claim 5, characterized in that, The chemical analysis in step (5.2) includes: major and minor analysis, quantitative clay X diffraction analysis, organic carbon analysis, total sulfur analysis, redox potential analysis, pH analysis, and acid hydrolysis hydrocarbon analysis.

7. The evaluation method for target layers in sandstone-type uranium deposits according to claim 6, characterized in that, Step (6) includes: Step (6.1): Evaluate the post-harvest uranium accumulation capability of the target layer based on environmental geochemical indicators; Step (6.2): ​​Based on the comparative analysis of geochemical indicators of sandstones of different colors, determine the characteristics and intensity of post-oxidation or secondary reduction in the target layer; Step (6.3): Based on the comparative analysis of geochemical indicators of sandstone and mudstone, comprehensively evaluate the uranium mineralization environment, mineralization potential, and scale of the sandstone in the target mineralization layer of the survey area.

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