Sandstone type uranium ore enrichment area positioning method based on material source-sedimentary lobes

Abstract

The invention provides a sandstone type uranium ore enrichment area positioning method based on a material source-sedimentary lobe, and the method comprises the following steps: collecting field core logging and drilling data, and building a uranium-bearing rock series stratigraphic framework; performing ore control factor data statistics according to the uranium-bearing rock series stratigraphic framework, importing corresponding statistical data into a drawing tool, and generating a uranium reservoir spatial distribution diagram and a uranium reservoir heavy mineral spatial distribution diagram; according to the uranium reservoir spatial distribution diagram and the heavy mineral spatial distribution diagram, obtaining a material source direction and a sedimentary lobe range, and carrying out spatial description on a material source-sedimentary lobe body; rebuilding a uranium mineralization source and sink model by taking the material source-sedimentary lobes as units; according to the method, the ore control factors of the uranium reservoir, the reduced geologic body and the metamorphic alteration zoning are analyzed, the important prospecting mark is tracked by taking the material source-sedimentary lobe as the unit, and the spatial distribution of the uranium mineralization body is predicted according to the important prospecting mark, so that the ore exploration accuracy and prospecting efficiency of the sandstone type uranium ore are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of uranium exploration, and particularly relates to a method for positioning a sandstone-type uranium enrichment area based on a source-deposition petal. BACKGROUND

[0002] The formation of a sandstone-type uranium deposit is largely dependent on the deposition process. The deposition of a surface water system is a link between an orogenic belt and a sedimentary basin, which restricts the migration and transportation path of uranium. Therefore, the source-sink system in a sedimentary basin is of great significance in revealing the sandstone-type uranium mineralization process. The core of the source-sink system analysis for a uranium-bearing rock series in a uranium-producing basin is to identify a large source-deposition petal, which can provide an important basis for the deployment of sandstone-type uranium exploration. The properties of the source area parent rock directly determine the material composition of the uranium reservoir in the basin. The distribution of the uranium reservoir directly determines the physical space of uranium mineralization. A uranium reservoir with moderate size is a primary and essential condition for the formation of a sandstone-type uranium deposit. The uranium reservoir is an important carrier for the migration and storage of ore-forming fluids. The internal structure of the uranium reservoir restricts the direction and trajectory of the development of the interlayer oxidation zone, and the material composition of the uranium reservoir controls the distance of the interlayer oxidation zone and the position of the front line. Uranium mineralization occurs near the geochemical barrier formed by the boundary of the interlayer oxidation zone.

[0003] A large data geological analysis method for sandstone-type uranium mineralization prediction is disclosed in CN111090709A. The method includes the following steps: collecting data and preprocessing to form a database; establishing a sandstone-type uranium exploration model; performing technical analysis and effective information extraction on the main ore-controlling factors and exploration indicators of the area to be searched for sandstone-type uranium deposits; and performing sandstone uranium prediction.

[0004] The traditional sandstone-type uranium mineralization prediction method relies on a single geological parameter or macro mineralization rule, which leads to insufficient spatial resolution and makes it difficult to capture the spatial coupling relationship of multiple ore-controlling factors such as source supply, sedimentary microfacies, and epigenetic alteration. Due to the lack of system integration of "source-deposition process-mineralization modification", the spatial and temporal evolution of geological processes is easily broken, resulting in the missing of key ore-controlling element analysis, and ultimately making the prediction target area boundary fuzzy, thereby reducing the accuracy and efficiency of sandstone-type uranium exploration. SUMMARY

[0005] Therefore, the present application provides a sandstone-type uranium enrichment area prediction method based on a source-deposition petal. The method analyzes uranium reservoirs, reducing geological bodies, and epigenetic alteration zoning ore-controlling factors, and traces important exploration indicators based on the source-deposition petal. The spatial distribution of uranium mineralization bodies is predicted according to the important exploration indicators, which improves the accuracy and efficiency of sandstone-type uranium exploration.

[0006] The technical scheme of the present application is implemented as follows: the present application provides a sandstone-type uranium deposit enrichment area positioning method based on a material source-deposition petal, comprising the following steps: S1, collecting field core records and drilling data, and establishing a uranium-bearing rock series stratigraphic framework; S2, performing ore-controlling factor data statistics according to the uranium-bearing rock series stratigraphic framework, importing corresponding statistical data into a drawing tool to generate a uranium reservoir spatial distribution map and a uranium reservoir heavy mineral spatial distribution map; S3, obtaining a material source direction and a deposition petal range according to the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map, and spatially depicting the material source-deposition petal; S4, importing corresponding statistical data into the drawing tool to generate a reduced geological body spatial distribution map and a post-formation alteration zoning spatial distribution map within the material source-deposition petal range; S5, obtaining a spatial configuration relationship of uranium mineralization and the uranium reservoir, the reduced geological body and the post-formation alteration zoning according to the uranium reservoir spatial distribution map, the reduced geological body spatial distribution map and the post-formation alteration zoning spatial distribution map, reconstructing a uranium metallogenic source-sink model according to the spatial configuration relationship and taking the material source-deposition petal as a unit; S6, tracking important ore-prospecting indicators according to the material source-deposition petal as a unit, and performing spatial prediction of a uranium deposit enrichment area according to the important ore-prospecting indicators.

[0007] On the basis of the above technical scheme, preferably, in step S1, the field core records and drilling data are collected, the drilling data include drilling data, logging, well logging, three-dimensional seismic and paleontological data in the study area, different color sand bodies and reduced geological bodies are identified according to the core records, the sequence stratigraphic interfaces and marker beds in the study area are determined according to the drilling data, the sequence stratigraphic units in the study area are contrasted and divided, and the uranium-bearing rock series stratigraphic framework is established.

[0008] On the basis of the above technical scheme, preferably, in step S2, the ore-controlling factor data statistics are performed according to the uranium-bearing rock series stratigraphic framework, including the following: the stratigraphic thickness, the reduced geological body thickness, the uranium reservoir data, the sand content, the oxidized sand body thickness and ratio, the uranium mineralization data and the heavy mineral data are statistically obtained according to the logging data and the sequence stratigraphic unit contrast and division results; the reduced geological body is defined as dark mudstone, dark silty mudstone, dark argillaceous siltstone, dark siltstone or mudstone, and the gray, light gray, grayish white, grayish green, grayish black, purple gray and black gray mudstone can all indicate a reducing environment; the oxidized sand body is defined as a multicolor sand body, and is classified and statistically obtained according to the color; the sand content of the sand body is the percentage content of the sand body thickness in the sequence stratigraphic unit, and the oxidized sand body ratio is the percentage content of the oxidized sand body thickness in the sand body thickness.

[0009] Based on the above technical scheme, preferably, in step S2, the ore-controlling factor data is counted according to the uranium-bearing rock series stratigraphic framework, the corresponding statistical data is introduced into a drawing tool, and a uranium reservoir spatial distribution map and a uranium reservoir heavy mineral spatial distribution map are generated, including the following sub-steps: S21, the ore-controlling factor data is counted according to the uranium-bearing rock series stratigraphic framework, the corresponding statistical data is introduced into a three-dimensional drawing tool, the drilling hole positions and corresponding uranium reservoir data, heavy mineral data and uranium mineralization data of the study area are projected respectively, and a corresponding contour map is generated by using a spatial interpolation algorithm; S22, the drilling hole positions and corresponding uranium reservoir data, heavy mineral data and uranium mineralization data and the corresponding contour map are introduced into a plane drawing tool; S23, the different ore-controlling factor data, heavy mineral data and uranium mineralization data in the same value range interval are divided, circled, connected and filled with different colors according to the plane drawing tool, and a uranium reservoir spatial distribution map and a uranium reservoir heavy mineral spatial distribution map are obtained.

[0010] Based on the above technical scheme, preferably, in step S3, the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map are used to obtain a source direction and a sedimentation petal range, and the source-sedimentation petal is spatially depicted, including analyzing the uranium reservoir spatial distribution and the heavy mineral spatial distribution, determining the source direction by the low value to the high value of the heavy mineral on the plane map, determining the sedimentation petal range from the high value area to the low value area of the sand body thickness and sand content on the plane map, wherein the heavy mineral source direction is consistent with the uranium reservoir source direction, and the source-sedimentation petal is spatially depicted in combination with the source direction and the sedimentation petal range.

[0011] Based on the above technical scheme, preferably, in step S4, the corresponding statistical data is introduced into a drawing tool within the source-sedimentation petal range to generate a reduced geological body spatial distribution map and a epigenetic alteration zoning spatial distribution map, including the following sub-steps: S41, the corresponding statistical data is introduced into a three-dimensional drawing tool within the source-sedimentation petal range, the thickness data of the reduced geological body of the dark fine-grained sediment and the residual sediment, the thickness data of the oxidized sand body and the sand ratio data are projected respectively, and a corresponding contour map is generated by using a spatial interpolation algorithm; S42, the thickness data of the reduced geological body of the dark fine-grained sediment and the residual sediment, the thickness data of the oxidized sand body and the sand ratio data and the corresponding contour map are introduced into a plane drawing tool, and are spatially superimposed with the source-sedimentation petal boundary; S43, according to the data distribution characteristics, the reduced geologic body data, the oxidized sand body thickness and the ratio data in the same value range interval are connected by division and circle, and the closed interval of different value ranges is filled with colors to generate a reduced geologic body spatial distribution map; S44, according to the oxidized sand body ratio, different value range intervals are divided, and the epigenetic alteration subzone is divided into an oxidation zone, a transition zone and a reduction zone; the color filling is performed on each subzone to generate an epigenetic alteration subzone spatial distribution map.

[0012] On the basis of the above technical scheme, preferably, in step S5, the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduced geologic body and the epigenetic alteration subzone is obtained according to the uranium reservoir spatial distribution map, the uranium reservoir heavy mineral spatial distribution map, the reduced geologic body spatial distribution map and the epigenetic alteration subzone spatial distribution map, including: using a plane drawing tool to superimpose the uranium mineralization respectively with the spatial distribution of the uranium reservoir, the reduced geologic body and the epigenetic alteration subzone map to obtain the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduced geologic body and the epigenetic alteration subzone respectively, the spatial configuration relationship including the relative position and distribution characteristics and contact relationship of the uranium mineralization respectively with the uranium reservoir, the reduced geologic body and the epigenetic alteration subzone on the plane, the relative position being the shortest distance from the geometric center of the mineralization body to the source-sediment lobe boundary, the distribution characteristics being the angle between the long axis direction of the mineralization body and the source direction, and the contact relationship being the proportion of the contact length of the mineralization body boundary and the oxidation-transition zone boundary to the perimeter of the mineralization body.

[0013] On the basis of the above technical scheme, preferably, in step S5, the uranium metallogenic source-sink model is reconstructed according to the spatial configuration relationship and taking the source-sediment lobe as a unit, including: the source-sediment lobe is spatially depicted according to the uranium reservoir and the uranium reservoir heavy mineral; when the reduced geologic body is continuously distributed in a strip shape and the thickness is >5m, it is regarded as an effective reduction barrier, and when the dark mudstone area ratio is >30%, it is defined as the existence of large-scale reduction medium; when the uranium reservoir is externally surrounded by the reduction medium, the epigenetic alteration subzone front line is determined through the spatial distribution map of the reduced geologic body; the ore-forming flow field is restored, and the uranium metallogenic source-sink model is reconstructed.

[0014] On the basis of the above technical scheme, preferably, in step S6, important ore-prospecting marks are tracked taking the source-sediment lobe as a unit, including: the uranium mineralization thickness map is superimposed respectively on the sand body thickness map, the sand content map, the dark fine-grained sediment thickness map, the retained sediment thickness map and the epigenetic alteration subzone spatial distribution map through a plane drawing tool, the frequency statistics of each ore-controlling factor data in the superimposed area is performed, the corresponding statistical cumulative frequency quantile is determined, the best interval division threshold of the ore-forming target area is obtained; the quantile corresponding to the cumulative frequency of 85% is determined to obtain the uranium reservoir thickness division threshold interval A1-A2 of the type I target area, the sand content division threshold B 1. Dark mudstone thickness division threshold C1 and distance threshold D1 of the alteration front line.

[0015] Based on the above technical solutions, preferably, step S6, which involves spatial prediction of uranium enrichment areas based on important mineral exploration indicators, includes the following sub-steps: S61, by using drawing tools, the sand content line of uranium reservoir, the thickness contour lines of dark fine-grained sediments in reduced geological bodies, and the thickness contour lines of retained sediments are overlaid on the uranium reservoir thickness map, and the contour lines of various ore-controlling factors are marked with color and thickness to distinguish different types of ore-controlling factors; S62, using provenance-sedimentary lobes as units, performs spatial prediction of uranium enrichment areas based on different types of ore-controlling factors and optimal interval division thresholds for ore-forming target areas, classifying ore-forming target areas into three categories: Class I target areas are delineated based on the following criteria: A2 > uranium reservoir thickness > A1, and sand content > B 1. Thickness of dark mudstone > C1; Target area located in redox transition zone; Distance of alteration front < 50m; The criteria for delineating a Class II target area are: A2 > uranium reservoir thickness > A1, sand content > B 1. At least one of the following conditions must be met: the thickness of dark mudstone is greater than C1; the target area is located in the redox transition zone; and the distance from the alteration front is less than 50m. Category III target areas are defined by criteria that do not meet the following: A2 > uranium reservoir thickness > A1, sand content > B 1. Thickness of dark mudstone > C1; target area located in redox transition zone; alteration front distance < 50m.

[0016] The method for locating sandstone-type uranium deposit enrichment areas based on provenance-sedimentary lobes of the present invention has the following advantages over existing technologies: (1) By setting up analysis of key ore-controlling factors such as uranium reservoir, reduced geological body and post-alteration zoning, and characterizing source-sedimentary lobes based on the spatial distribution of uranium reservoir and heavy minerals, important prospecting indicators are tracked based on source-sedimentary lobes, and the spatial distribution of uranium mineralization is predicted based on important prospecting indicators, which improves the accuracy and efficiency of exploration in sandstone-type uranium-rich areas; (2) By accurately depicting the source direction and the range of sedimentary lobes, the distribution pattern of sand bodies in three-dimensional space is revealed, providing a basis for the location of uranium mineralization bodies. Furthermore, the source direction indicates the sediment transport path, and the range of sedimentary lobes delineates favorable uranium reservoirs, which can determine potential uranium mineralization enrichment areas and significantly improve the accuracy and efficiency of exploration. (3) By reconstructing the uranium mineralization source-sink model, the source area is the source area, the sink area is the sedimentation center, and the channel includes permeable sand bodies and fault zones, the spatial coupling relationship between uranium mineralization and uranium reservoirs, reduced geological bodies and alteration zones is clarified, and the migration process of uranium from the source area to the sink area through the channel is dynamically displayed, which improves the accuracy of target area prediction and provides data support for exploration. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the method of the present invention; Figure 2 (a) represents the southern region of the Songliao Basin (SQ). K2y - EST heavy mineral ZTR index planar distribution map Figure 2 (b) represents the southern region of the Songliao Basin (SQ). K2y -EST uranium reservoir thickness planar distribution map; Figure 3 (a) represents the southern region of the Songliao Basin (SQ). K2y -EST dark fine-grained sediment thickness planar distribution map Figure 3 (b) represents the southern region of the Songliao Basin (SQ). K2y -EST post-alteration alteration zoning planar distribution diagram; Figure 4 This is a diagram showing the relationship between different key ore-controlling factors and the spatial configuration of uranium mineralization in an embodiment of the present invention. Figure 4 The middle (a) figure shows the SQ region in the southern part of the Songliao Basin. K2y - EST diagram showing the spatial configuration of uranium ore layers and uranium mineralization. Figure 4 The middle (b) map shows the SQ region in the southern part of the Songliao Basin. K2y -EST diagram showing the spatial configuration of reduced geological bodies and uranium mineralization Figure 4 The middle (c) figure shows the SQ region in the southern part of the Songliao Basin. K2y -Diagram showing the relationship between EST post-alteration alteration zoning and spatial configuration of uranium mineralization; Figure 5 This is a spatial prediction map of sandstone-type uranium deposit enrichment areas according to an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1As shown, a method for locating a sandstone-type uranium enrichment area based on a source-sedimentary petal of the application comprises the following steps: In this embodiment, by analyzing key ore-controlling factors such as uranium reservoirs, reducing geological bodies and epigenetic alteration zonation, and according to the spatial distribution of uranium reservoirs and heavy minerals, the source-sedimentary petal is depicted, important ore-prospecting marks are tracked in units of source-sedimentary petal, the spatial distribution of uranium mineralization bodies is predicted according to the important ore-prospecting marks, and the accuracy and efficiency of the exploration of the sandstone-type uranium enrichment area are improved. The following takes a source-sedimentary petal in the lake expansion system domain of the Yaojia Formation in the southern Songliao Basin as an example for illustration.

[0021] S1, collect field core records and drilling data, and establish a uranium-bearing rock series stratigraphic framework.

[0022] In step S1, field core records and drilling data are collected, the drilling data include drilling data, logging, well logging, three-dimensional seismic and paleontological data in the study area, different color sand bodies and reducing geological bodies are identified according to the core records, the sequence stratigraphic interfaces and marker beds in the study area are determined according to the drilling data, the sequence stratigraphic units in the study area are compared and divided, and a uranium-bearing rock series stratigraphic framework is established.

[0023] It should be noted that the basic rock is identified by core observation, the sand body types and reducing geological bodies are distinguished, which provides basic data for stratigraphic division. The core color, mineral composition, structure and alteration phenomena are observed; different color sand bodies are distinguished; the color of the sand body is often related to its composition, sedimentary environment and later reformation, different color sand bodies represent different sedimentary stages or sedimentary environments, and have different control effects on uranium mineralization; red / brown sand bodies indicate an oxidizing environment, and gray / gray-green sand bodies indicate a reducing environment. The sand body particle size can be distinguished by screening method or laser particle size instrument, which can distinguish high-energy and low-energy sedimentary environments. In addition, the reducing geological body is one of the important factors in the process of uranium mineralization. The reducing geological body is identified by core records, including geochemical markers and lithological markers. The geochemical markers include high organic matter content, sulfide enrichment and reducing element anomaly. The lithological markers include dark mudstone, retained sediment or organic matter-containing siltstone.

[0024] In addition, logging data of each drill hole are obtained, such as vertical change of lithology in the drill hole, natural gamma logging, resistivity logging, spontaneous potential logging, etc. The logging data can reflect the physical properties of the stratum, such as porosity, permeability, water content, etc., and have an important auxiliary role in stratigraphic division and identification of uranium-bearing rock series. Seismic data can identify regional unconformities according to seismic reflection interfaces and divide sedimentary system domains through seismic facies analysis. Paleontological data in the study area are collected, which can reflect the age and sedimentary environment of the stratum.

[0025] Establishing the isochronous stratigraphic framework, making clear the vertical distribution of uranium-bearing rock series, and establishing the sequence stratigraphic interface and marker bed of the study area; the sequence stratigraphic interface is an important basis for stratigraphic division, and the marker bed is a stratigraphic unit with specific lithology, lithofacies or paleontological characteristics, which is easy to identify and track; on the basis of establishing the sequence stratigraphic interface and marker bed, the strata of the study area are divided, the lithology column of logging is used, the sand body thickness, color and sedimentary sequence are used for lateral lithology comparison, the gamma curve shape is matched with the strata of adjacent boreholes for well logging curve comparison, the strata age is limited for paleontological constraint combining with fossil assemblage, the three-dimensional stratigraphic model is constructed by integrating borehole, well logging and seismic data, the spatial distribution of uranium-bearing rock series is made clear by taking the sequence interface as the framework and dividing the system tract; through the establishment of stratigraphic framework, the spatial distribution rule of uranium-bearing rock series can be clearly shown, which provides a basis for subsequent spatial positioning and prediction of uranium ore-rich bodies.

[0026] In step S2, the data statistics of ore-controlling factors are carried out according to the stratigraphic framework of uranium-bearing rock series, the corresponding statistical data are introduced into a drawing tool, and a uranium reservoir spatial distribution map and a uranium reservoir medium-heavy mineral spatial distribution map are generated.

[0027] In step S2, the data statistics of ore-controlling factors are carried out according to the stratigraphic framework of uranium-bearing rock series, including the statistics of strata thickness, reduced geological body thickness, uranium reservoir data, sand content, oxidized sand body thickness and ratio, uranium mineralization data and heavy mineral data according to logging data and sequence stratigraphic unit comparison and division results; the reduced geological body is defined as dark mudstone, dark silty mudstone, dark argillaceous siltstone, dark siltstone or mudstone, and the gray, light gray, gray-white, gray-green, gray-black, purple-gray and black-gray mudstone can indicate the reducing environment; the oxidized sand body is defined as a multicolor sand body and is classified and counted according to color; the sand content of the sand body is the percentage of the thickness of the sand body in the sequence stratigraphic unit, and the ratio of the oxidized sand body is the percentage of the thickness of the oxidized sand body in the thickness of the sand body.

[0028] It should be noted that the oxidized sand body is defined as a multicolor sand body and is classified and counted according to color, which can be divided into gray-brown, yellow-brown, brown-brown, light brown, dark brown, brown-red, dark red, light red, brown-red, gray-purple, purple-red, purple, red-yellow, brown-purple, gray-brown sand body, light yellow, dark yellow, brown-yellow, light gray-yellow, dark gray-yellow, turmeric yellow, clay yellow sand body and miscellaneous sand body, which all belong to the oxidized sand body.

[0029] In step S2, the following sub-steps are included: In step S21, the data statistics of ore-controlling factors are carried out according to the stratigraphic framework of uranium-bearing rock series, the corresponding statistical data are introduced into a three-dimensional drawing tool, the well sites of each borehole in the study area and the corresponding uranium reservoir data, heavy mineral data and uranium mineralization data are projected respectively, and the corresponding contour maps are generated by using a spatial interpolation algorithm; S22, import each drilling well site and corresponding uranium reservoir data, heavy mineral data and uranium mineralization data and corresponding contour map into the plane drawing tool; S23, according to the plane drawing tool, divide and connect the different ore-controlling factor data, heavy mineral data and uranium mineralization data in the same value range interval, and give different colors to fill the closed interval of different value ranges, to obtain the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map in the uranium reservoir.

[0030] It should be noted that after the establishment of the uranium-bearing rock series stratigraphic framework, the ore-controlling factor data statistical work is carried out according to the framework; through the collection, arrangement and analysis of a variety of related data, the statistical data is imported into the drawing tool to generate the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map in the uranium reservoir. Through the generated uranium reservoir spatial distribution map and the heavy mineral spatial distribution map in the uranium reservoir, the spatial distribution of uranium reservoir and heavy mineral in the study area can be intuitively displayed, which provides intuitive reference for subsequent exploration work.

[0031] As shown in Figure 2 S3, according to the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map, the source direction and the sedimentary petal range are obtained, and the source-sedimentary petal is spatially depicted.

[0032] In step S3, the uranium reservoir spatial distribution and the heavy mineral spatial distribution are analyzed, the source direction is determined by the low value to the high value of the heavy mineral on the plane map, and the sedimentary petal range is determined by the high value area to the low value area of the sand thickness and sand content on the plane map. The heavy mineral source direction is consistent with the uranium reservoir source direction, and the source-sedimentary petal is spatially depicted in combination with the source direction and the sedimentary petal range.

[0033] It should be noted that through the heavy mineral spatial distribution map, the types, contents and combination characteristics of heavy minerals in different regions are analyzed. The high value area of stable heavy mineral proportion is usually close to the source area, and the high value area of unstable heavy mineral proportion reflects the sedimentary reworking effect. The source direction is verified by tracking the gradient change of the heavy mineral on the plane map from the low value area to the high value area, combining the heavy mineral ZTR index or stability coefficient, and comparing the uranium mineralization data in the uranium reservoir with the heavy mineral source direction. If the spatial distribution of the two is consistent, that is, the high value area of uranium mineralization and the high value area of heavy mineral overlap, it indicates that the source direction has a control effect on uranium mineralization. In combination with the spatial distribution of the high value area of sand thickness and sand content, if the high value area extends in a fan shape or petal shape to a certain direction, the source direction can be verified.

[0034] In the plan view, the high value area of sand body thickness and sand ratio represents the main part of the sedimentary bud, the contour map is generated by the spatial interpolation algorithm, the mutation low value area of sand body thickness or sand ratio is taken as the boundary of the sedimentary bud, the low value area boundary is determined, and then the range of the sedimentary bud is determined; the source direction and the range of the sedimentary bud are introduced into the three-dimensional geological modeling software to construct the three-dimensional space model of the source-sedimentary bud, the spatial relationship between the source channel and the sedimentary bud is determined through the model visualization, the source direction, the deposition rate and other parameters are input into the sedimentary process simulation software to simulate the formation process of the sedimentary bud, and the simulation result is compared and verified with the actual geological data to complete the spatial depiction of the source-sedimentary bud.

[0035] Through the accurate depiction of the source direction and the range of the sedimentary bud, the distribution rule of the sand body in the three-dimensional space is revealed, which provides a basis for the positioning of the uranium mineralization body, and the source direction indicates the deposition path, the range of the sedimentary bud determines the favorable sedimentary facies belt, the potential enrichment area of the uranium mineralization can be determined, and the exploration accuracy and efficiency are significantly improved.

[0036] As shown in Figure 3 S4, in the source-sedimentary bud range, the corresponding statistical data is introduced into the drawing tool to generate the reduced geological body space distribution map and the epigenetic alteration zoning space distribution map.

[0037] Step S4 includes the following sub-steps: S41, in the source-sedimentary bud range, the corresponding statistical data is introduced into the three-dimensional drawing tool to project the thickness data of the reduced geological body of dark fine-grained sediment and the thickness data of the retained sediment, the thickness and ratio data of the oxidized sand body in the study area, and the corresponding contour map is generated by using the spatial interpolation algorithm; S42, the thickness data of the reduced geological body of dark fine-grained sediment and the thickness data of the retained sediment, the thickness and ratio data of the oxidized sand body and the corresponding contour map are introduced into the plan drawing tool and are spatially overlaid with the source-sedimentary bud boundary; S43, according to the data distribution characteristics, the reduced geological body data, the thickness and ratio data of the oxidized sand body in the same value range interval are connected and divided, and the closed interval of different value ranges is given color filling to generate the reduced geological body space distribution map; S44, according to the different value range interval of the oxidized sand body ratio, the epigenetic alteration zoning is divided into oxidation zone, transition zone and reduction zone, and each zoning is color filled to generate the epigenetic alteration zoning space distribution map.

[0038] It should be noted that the division of the interlayer oxidation zone of the lake expansion system domain of the Yaojia Formation is based on the thickness of the oxidized sandstone to calculate the percentage content of the oxidized sand body as the standard. The interlayer oxidation zone is divided into an oxidation zone, a transition zone and a reduction zone. The oxidation zone is divided into a completely oxidized sub-zone and a partially oxidized sub-zone. The percentage content of the oxidized sand body in the completely oxidized sub-zone is 100%, the percentage content of the oxidized sand body in the partially oxidized sub-zone is 60%≤ Y L <100%, the percentage content of the oxidized sand body in the transition zone is 0%≤ Y L <60%; and the percentage content of the oxidized sand body in the reduction zone is 0%. Y L Y L = The division standard of the interlayer oxidation zone is not completely the same in different regions. In this embodiment, the core distribution area of the reduction geological body is determined by the spatial superposition of the dark fine-grained sediment and the stagnant sediment, which provides a reduction barrier for uranium mineralization.

[0039] As shown in Figure 4 , S5, according to the spatial distribution map of the uranium reservoir, the spatial distribution map of the reduction geological body and the spatial distribution map of the epigenetic alteration zone, the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduction geological body and the epigenetic alteration zone is obtained. According to the spatial configuration relationship, and taking the source-sedimentary lobe as a unit, the source-sink model of uranium mineralization is reconstructed.

[0040] In step S5, according to the spatial distribution map of the uranium reservoir, the spatial distribution map of the heavy mineral in the uranium reservoir, the spatial distribution map of the reduction geological body and the spatial distribution map of the epigenetic alteration zone, the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduction geological body and the epigenetic alteration zone is obtained. The spatial configuration relationship includes the relative position and distribution characteristics and contact relationship of the uranium mineralization and the uranium reservoir, the reduction geological body and the epigenetic alteration zone on the plane. The relative position is the shortest distance from the geometric center of the mineralization body to the source-sedimentary lobe boundary. The distribution characteristics are the angle between the long axis direction of the mineralization body and the source direction. The contact relationship is the proportion of the contact length of the mineralization body boundary and the oxidation-transition zone boundary to the perimeter of the mineralization body.

[0041] ​It should be noted that the relative position is the shortest distance D from the geometric center of the mineralization body to the source-sedimentary lobe boundary, combined with the lobe radius R, to define the relative position index D / R; if D / R < 0.3, it indicates that the mineralization body is close to the source area; D / R > 0.7 is close to the sedimentary center; distribution characteristics: measure the angle θ between the long axis direction of the mineralization body and the source direction; if θ < 30°, it indicates that the mineralization body is distributed along the source direction; calculate the contact length L of the mineralization body boundary and the oxidation-transition zone boundary line, and the proportion L / C of the length L to the perimeter C of the mineralization body; if L / C > 50%, it indicates that the mineralization body is controlled by the oxidation-reduction interface.

[0042] In step S5, the source-sedimentary lobe is taken as a unit to reconstruct the uranium ore-forming source-sink model according to the spatial configuration relationship, including: the uranium reservoir and the heavy minerals in the uranium reservoir are used to spatially depict the source-sedimentary lobe; when the reducing geological body is distributed in a continuous strip and the thickness is > 5m, it is taken as an effective reducing barrier; when the dark mudstone area ratio is > 30%, it is defined as the existence of large-scale reducing medium; when the uranium reservoir is outside the reducing medium, the epigenetic alteration subzone front line is determined through the spatial distribution map of the reducing geological body; the ore-forming flow field is restored, and the uranium ore-forming source-sink model is reconstructed.

[0043] It should be noted that the epigenetic alteration front line is determined by tracking the oxidation-reduction transition zone, and in the spatial distribution map of the reducing geological body, the boundary line where the oxidation sand body ratio suddenly decreases from > 70% to < 40% is identified as the epigenetic alteration front line; the front line protrudes towards the source direction, which is the uranium pre-enrichment area; combined with the source direction, sand body distribution and fault distribution, the migration path of uranium-bearing fluid from the oxidation zone to the reduction zone is restored, the source-sink model is reconstructed, the source area is the source area, the sink area is the sedimentary center, the channel includes permeable sand body and fault zone, the spatial coupling relationship between uranium mineralization and uranium reservoir, reducing geological body and alteration subzone is clear, the uranium ore-forming source-sink model is reconstructed, the migration process of uranium from the source area to the sink area through the channel is dynamically displayed, the target area prediction accuracy is improved, and data support is provided for exploration.

[0044] As shown in Figure 5 S6, the important ore-prospecting indicators are tracked in the source-sedimentary lobe unit, and the uranium ore enrichment area is spatially predicted according to the important ore-prospecting indicators.

[0045] In this example, the important ore-prospecting indicators are tracked in the source-sedimentary lobe unit in step S6, including: the uranium mineralization thickness map is superimposed on the sand body thickness map, sand content map, dark fine-grained sediment thickness map, retained sediment thickness map and epigenetic alteration subzone spatial distribution map respectively through plane drawing tools, the frequency statistics of each ore-controlling factor data in the superimposed area is carried out, the corresponding statistical cumulative frequency quantile number is determined, and the best interval division threshold value of the ore-forming target area is obtained; the quantile number corresponding to the cumulative frequency of 85% of the corresponding thickness is determined, and the uranium reservoir thickness division threshold interval of the type I target area is A1-A2, the sand content division threshold B1. Threshold C1 for defining the thickness of dark mudstone and threshold D1 for the distance of the alteration front.

[0046] It should be noted that in step S6, important mineral exploration indicators are tracked using the provenance-sedimentary lobes as units. Through the configuration relationship between uranium mineralization and uranium reservoirs, it is determined that uranium mineralization is mainly distributed in uranium reservoirs with a thickness of 60-90m, i.e., A1=60m, A2=90m. The configuration relationship between uranium mineralization and sand content is also determined using the same method, showing that a sand content of 70-90% is more favorable for uranium mineralization formation. B 1=75%; By superimposing uranium mineralization with reducing geological bodies, the configuration relationship between uranium mineralization and the thickness of dark fine-grained sediments is summarized. It can be found that a thickness of dark fine-grained sediments <10m is more favorable for uranium mineralization formation, C1=10m. The configuration relationship between uranium mineralization and the thickness of retained sediments is still done using the same method. By superimposing uranium mineralization with epigenetic alteration zoning, it is found that uranium mineralization mainly develops in the transition zone between inter-oxidation zones and near the front line of epigenetic alteration zoning. A distance < from the alteration front line is more favorable for uranium mineralization formation, D1=50m.

[0047] Step S6 involves spatial prediction of uranium enrichment areas based on important mineral exploration indicators, including the following sub-steps: S61, by using drawing tools, the sand content line of uranium reservoir, the thickness contour lines of dark fine-grained sediments in reduced geological bodies, and the thickness contour lines of retained sediments are overlaid on the uranium reservoir thickness map, and the contour lines of various ore-controlling factors are marked with color and thickness to distinguish different types of ore-controlling factors; S62, using provenance-sedimentary lobes as units, performs spatial prediction of uranium enrichment areas based on different types of ore-controlling factors and optimal interval division thresholds for ore-forming target areas, classifying ore-forming target areas into three categories: Class I target areas are delineated based on the following criteria: A2 > uranium reservoir thickness > A1, and sand content > B 1. Thickness of dark mudstone > C1; Target area located in redox transition zone; Distance of alteration front < 50m; The criteria for delineating a Class II target area are: A2 > uranium reservoir thickness > A1, sand content > B 1. At least one of the following conditions must be met: the thickness of dark mudstone is greater than C1; the target area is located in the redox transition zone; and the distance from the alteration front is less than 50m. Category III target areas are defined by criteria that do not meet the following: A2 > uranium reservoir thickness > A1, sand content > B 1. Thickness of dark mudstone > C1; target area located in redox transition zone; alteration front distance < 50m.

[0048] It should be noted that by tracking the ore prospecting marks with the material source-sedimentary lobe as a unit and based on the quantitative threshold for spatial prediction, the efficient delineation of the uranium enrichment area is realized, and the accuracy and efficiency of the sandstone type uranium ore exploration are improved.

[0049] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for locating sandstone-type uranium ore enrichment areas based on provenance-sedimentary lobes, characterized in that: The method comprises the following steps: S1, collecting field core records and drilling data to establish a uranium-bearing rock series stratigraphic framework; S2, according to the uranium-bearing rock series stratigraphic framework, performing ore-controlling factor data statistics, and importing corresponding statistical data into a drawing tool to generate a uranium reservoir spatial distribution map and a uranium reservoir heavy mineral spatial distribution map; S3, according to the uranium reservoir spatial distribution map and the heavy mineral spatial distribution map, obtaining a source direction and a sedimentation petal range, and performing spatial delineation on the source-sedimentation petal; S4, within the source-sedimentation petal range, importing corresponding statistical data into a drawing tool to generate a reduced geological body spatial distribution map and a post-formation alteration zoning spatial distribution map; S5, according to the uranium reservoir spatial distribution map, the reduced geological body spatial distribution map and the post-formation alteration zoning spatial distribution map, obtaining a spatial configuration relationship of uranium mineralization, uranium reservoir, reduced geological body and post-formation alteration zoning, and according to the spatial configuration relationship, reconstructing a uranium metallogenic source-sink model with the source-sedimentation petal as a unit; S6, tracking important ore-prospecting indicators with the source-sedimentation petal as a unit, and performing spatial prediction on a uranium ore enrichment area according to the important ore-prospecting indicators.

2. The method for locating sandstone-type uranium ore enrichment areas based on source-deposition lobe according to claim 1, characterized in that, In step S1, field core records and drilling data are collected, drilling data includes drilling data in the research area, logging, well logging, three-dimensional seismic and paleontological data, different color sand bodies and reduced geological bodies are identified according to the core records, and the sequence stratigraphic interface and marker bed in the research area are determined according to the drilling data, the sequence stratigraphic units in the research area are compared and divided, and a uranium-bearing rock series stratigraphic framework is established.

3. The method for locating sandstone-type uranium ore enrichment areas based on source-deposition lobe according to claim 1, characterized in that, In step S2, according to the uranium-bearing rock series stratigraphic framework, ore-controlling factor data statistics are performed, including according to logging data and sequence stratigraphic unit comparison and division results, statistics of stratigraphic thickness, reduced geological body thickness, uranium reservoir data, sand content, oxidized sand body thickness and ratio, uranium mineralization data and heavy mineral data; the reduced geological body is defined as dark mudstone, dark silty mudstone, dark argillaceous siltstone, dark siltstone or mudstone, and gray, light gray, gray-white, gray-green, gray-black, purple-gray and black-gray mudstone can all indicate a reducing environment; the oxidized sand body is defined as a multicolored sand body and is classified and counted according to color; the sand content of the sand body is the percentage of the thickness of the sand body in the sequence stratigraphic unit, and the ratio of the oxidized sand body is the percentage of the thickness of the oxidized sand body in the thickness of the sand body.

4. The method for locating sandstone-type uranium ore enrichment areas based on source-deposition lobe according to claim 3, characterized in that, In step S2, according to the uranium-bearing rock series stratigraphic framework, ore-controlling factor data statistics are performed, and corresponding statistical data are imported into a drawing tool to generate a uranium reservoir spatial distribution map and a uranium reservoir heavy mineral spatial distribution map, including the following sub-steps: S21, according to the uranium-bearing rock series stratigraphic framework, ore-controlling factor data statistics are performed, and corresponding statistical data are imported into a three-dimensional drawing tool to project each drilling well site in the research area and corresponding uranium reservoir data, heavy mineral data and uranium mineralization data, and a corresponding contour map is generated by using a spatial interpolation algorithm; S22, each drilling well site and corresponding uranium reservoir data, heavy mineral data and uranium mineralization data and the corresponding contour map are imported into a plane drawing tool; S23, according to the plan drawing tool, the different ore-controlling factor data, heavy mineral data and uranium mineralization data in the same value range interval are divided, connected and filled with different colors in the closed interval of different value ranges, so as to obtain the spatial distribution map of uranium reservoir and the spatial distribution map of heavy minerals in the uranium reservoir.

5. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 4, characterized in that, In step S3, the source direction and the sedimentation petal range are obtained according to the spatial distribution map of the uranium reservoir and the spatial distribution map of the heavy minerals, and the source-sedimentation petal is spatially depicted, including: the source direction is determined by analyzing the spatial distribution of the uranium reservoir and the spatial distribution of the heavy minerals, and the heavy mineral value on the plan is from low to high; the sedimentation petal range is determined by the high value area to the low value area of the sand body thickness and sand content on the plan; the source direction of the heavy minerals is consistent with the source direction of the uranium reservoir; the source-sedimentation petal is spatially depicted in combination with the source direction and the sedimentation petal range.

6. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 5, characterized in that, In step S4, the corresponding statistical data is imported into the drawing tool within the source-sedimentation petal range to generate the reduced geological body spatial distribution map and the epigenetic alteration zoning spatial distribution map, including the following sub-steps: S41, the corresponding statistical data is imported into the three-dimensional drawing tool within the source-sedimentation petal range to project the dark fine-grained sediment thickness data and the retained sediment thickness data of the reduced geological body, the oxidation sand thickness and the sand ratio data of the study area, and the corresponding contour map is generated by using the spatial interpolation algorithm; S42, the dark fine-grained sediment thickness data and the retained sediment thickness data of the reduced geological body, the oxidation sand thickness and the sand ratio data and the corresponding contour map are imported into the plan drawing tool and spatially superimposed with the source-sedimentation petal boundary; S43, according to the data distribution characteristics, the reduced geological body data and the oxidation sand thickness and ratio data in the same value range interval are divided, connected and filled with different colors in the closed interval of different value ranges, so as to generate the reduced geological body spatial distribution map; S44, according to the oxidation sand ratio, the different value range interval is divided, and the epigenetic alteration zoning is divided into oxidation zone, transition zone and reduction zone, and the color filling is performed on each zoning to generate the epigenetic alteration zoning spatial distribution map.

7. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 6, characterized in that, In step S5, the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduced geological body and the epigenetic alteration zoning is obtained according to the spatial distribution map of the uranium reservoir, the spatial distribution map of the heavy minerals in the uranium reservoir, the spatial distribution map of the reduced geological body and the spatial distribution map of the epigenetic alteration zoning, including: the spatial distribution of the uranium mineralization is superimposed with the spatial distribution of the uranium reservoir, the reduced geological body and the epigenetic alteration zoning map respectively by using the plan drawing tool, and the spatial configuration relationship between the uranium mineralization and the uranium reservoir, the reduced geological body and the epigenetic alteration zoning is obtained respectively, the spatial configuration relationship includes the relative position and distribution characteristics and contact relationship of the uranium mineralization and the uranium reservoir, the reduced geological body and the epigenetic alteration zoning on the plane, the relative position is the shortest distance from the geometric center of the mineralization body to the source-sedimentation petal boundary, the distribution characteristics is the included angle between the long axis direction of the mineralization body and the source direction, and the contact relationship is the proportion of the contact length of the mineralization body boundary and the oxidation-transition zone boundary to the perimeter of the mineralization body.

8. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 7, characterized in that, In step S5, the uranium source-sink model is reconstructed according to the spatial configuration relationship and taking the source-sedimentary bud as a unit, including: the uranium reservoir and heavy minerals in the uranium reservoir are used to spatially depict the source-sedimentary bud; when the reduced geological body is in a continuous band-shaped distribution and the thickness is greater than 5 m, it is regarded as an effective reduction barrier; when the area ratio of dark mudstone is greater than 30%, it is defined as the existence of large-scale reduction medium; when the uranium reservoir is externally provided with a reduction medium, the epigenetic alteration subzone front line is determined through the spatial distribution map of the reduction geological body; the ore-forming flow field is restored, and the uranium source-sink model is reconstructed.

9. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 8, characterized in that, In step S6, important ore-prospecting marks are tracked in the unit of source-sedimentary lobe, including superimposing the uranium mineralization thickness map on the sand body thickness map, sand content map, dark fine-grained sediment thickness map, retained sediment thickness map and epigenetic alteration zoning spatial distribution map respectively by using plane drawing tools, frequency statistics of each ore-controlling factor data in the superimposed area is carried out, the corresponding statistical cumulative frequency percentile is determined, the best interval division threshold of the ore-forming target area is obtained; the corresponding percentile of the cumulative frequency of 85% is determined, and the uranium reservoir thickness division threshold interval of the type I target area is A1-A2, the sand content division threshold B 1, dark mudstone thickness division threshold C1 and distance threshold D1 of alteration front line.

10. The source-deposition lobe based sandstone-type uranium deposit enrichment zone positioning method according to claim 9, characterized in that, In step S6, the uranium ore enrichment area is spatially predicted according to important ore-prospecting indicators, including the following sub-steps: S61, the sand content line of the uranium reservoir, the isopleth of dark fine-grained sediments in the reduction geological body and the isopleth of retained sediments are respectively superimposed on the uranium reservoir thickness map through a drawing tool, and the isopleths of various ore-controlling factors are marked in color and thickness, and different types of ore-controlling factors are distinguished; S62, taking the source-sedimentary bud as a unit, the uranium ore enrichment area is spatially predicted according to different types of ore-controlling factors and the best interval division threshold of the ore-forming target area, and the ore-forming target area is divided into three categories: The delineation standard of the Class I target area satisfies A2>uranium reservoir thickness>A1, sand content> B 1 and dark mudstone thickness>C1; the target area is located in an oxidation-reduction transition zone; the alteration front line distance is less than 50 m; The delineation criteria of the type II target area are that A2>uranium reservoir thickness>A1, sand content> B 1 and dark mudstone thickness>C1; the target area is located in the redox transition zone; at least one condition in the alteration front line distance is less than 50 m; The delineation criteria of the type III target area are that none of the following is satisfied: A2>uranium reservoir thickness>A1, sand content> B 1 and dark mudstone thickness>C1; the target area is located in an oxidation-reduction transition zone; the alteration front line distance is less than 50 m.

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