A method for collaborative exploration and prospecting of post-magmatic hydrothermal type beryllium ore in plateau permafrost thick loess covered area

Abstract

The application discloses a kind of highland frozen soil thick loess covering area magmatic post-hydrothermal type beryllium ore exploration method for finding ore, comprising: obtaining the geological data of exploration area and constructing spatial database, and according to this, delineate ore-forming potential section;In the ore-forming potential section, synchronous development of geophysical prospecting, geochemical sampling through thick loess layer, and multi-source remote sensing data acquisition and alteration interpretation, respectively obtain three kinds of exploration data;Geological data, geophysical data, geochemical data and remote sensing alteration data are standardized in GIS platform Processing and weighted superposition fusion, generate comprehensive anomaly distribution map;According to the comprehensive anomaly distribution map, the grade of the ore-prospecting target area is divided, and the engineering verification is carried out on the divided ore-prospecting target area.The present application improves the positioning accuracy and exploration efficiency of concealed beryllium ore body by multi-means cooperative detection and multi-source data quantitative fusion, reduces the comprehensive exploration cost, and forms a standardized exploration operation system.

Description

Technical Field

[0001] This invention belongs to the field of solid metal mineral exploration technology, and in particular relates to a collaborative exploration method for post-magmatic hydrothermal beryllium deposits in areas covered by thick loess and permafrost in plateau regions. Background Technology

[0002] For special geomorphic units characterized by high-altitude mountains, extensive Quaternary aeolian loess cover, coexistence of seasonal and permanent permafrost, and extremely low natural bedrock exposure, the current main technical methods used in post-magmatic hydrothermal beryllium deposit exploration include: surface geological mapping, traditional drilling engineering, single geophysical exploration, shallow soil element measurement and remote sensing structural interpretation, supplemented by multi-source data overlay analysis based on human experience. Taking the Late Ordovician-Early Silurian granites of the South Qilian metallogenic belt as the parent rock for mineralization as an example, the granites in this type of area are mostly high-K calc-alkaline series, with zircon U-Pb ages concentrated between 430 and 460 Ma, and Rb-Sr ages closely related to beryllium mineralization at 425±5 Ma. Mineralization is synchronous with post-magmatic hydrothermal activity; northwest- and northeast-trending fault structures are well-developed, and the areas where secondary faults intersect at sharp angles are favorable spaces for ore fluid migration and enrichment. In such exploration areas, the above-mentioned existing technical methods have the following shortcomings: (1) Traditional surface geological mapping work can only identify mineralization clues exposed on the surface. Due to the obstruction of thick loess and weathered layers, this method is difficult to detect underground concealed beryllium ore bodies, and there is a significant shortcoming in deep exploration capability.

[0003] (2) Traditional drilling projects require penetrating the loess layer and the permafrost layer. The transportation conditions in high-altitude areas are poor, and it is difficult to transport large drilling equipment and carry out on-site construction. The overall exploration cost remains high, and the proportion of invalid boreholes is relatively high.

[0004] (3) Single geophysical exploration methods are easily affected by complex terrain, permafrost, and thick overburden. Geophysical anomaly interpretation has multiple interpretations and cannot accurately delineate the distribution range of ore-bearing structures and granite bodies.

[0005] (4) Traditional soil element measurement generally adopts a shallow sampling mode within 20 cm, and the sampling location is limited to the upper part of the surface loess and weathered layer. The sample is difficult to reflect the element characteristics of deep geological bodies, resulting in insufficient representativeness of the collected samples and significant weakening of beryllium ore-related abnormal signals.

[0006] (5) Traditional remote sensing interpretation focuses only on the identification of macroscopic linear and ring structures, without quantitative extraction and analysis of associated alteration minerals in beryllium ore, resulting in low accuracy of mineral exploration target area positioning.

[0007] (6) The existing multi-source exploration data integration methods are relatively crude and have not formed standardized integration rules. The overlay analysis of geological, geophysical, geochemical and remote sensing data is highly dependent on the personal experience of the operators. The data weighting is arbitrary, and the exploration efficiency and reliability of the results are poor.

[0008] In conclusion, the existing exploration technology system cannot meet the exploration needs of post-magmatic hydrothermal beryllium deposits in thickly overburdened plateau areas. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention proposes a collaborative exploration method for post-magmatic hydrothermal beryllium deposits in areas covered by thick loess and permafrost in plateau regions, thereby resolving the issues present in the existing technologies.

[0010] To achieve the above objectives, this invention provides a method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in areas covered by thick loess and permafrost in plateau regions, comprising: Obtain geological data of the exploration area, construct a geological database with spatial attributes based on the geological data, and delineate mineralization potential zones based on the geological database; Within the mineralization potential zone, geophysical exploration will be carried out simultaneously to obtain geophysical data, geochemical sampling will be conducted to penetrate the thick loess cover layer to obtain geochemical data, and multi-source remote sensing data will be collected and alteration interpretation will be performed to obtain remote sensing alteration data. The geological data, geophysical data, geochemical data, and remote sensing alteration data are standardized, weighted, and overlaid in a GIS platform to generate a comprehensive anomaly distribution map. Based on the comprehensive anomaly distribution map, prospecting target areas are classified into different levels, and engineering verification is carried out on the classified prospecting target areas.

[0011] Optionally, before obtaining geological data for the exploration area, the application conditions must be determined, including determining whether the exploration area simultaneously meets the geomorphological conditions, overburden conditions, and metallogenic geological conditions. The topographic conditions are plateau and mountainous terrain with an altitude of not less than 3500m, and seasonal or permanent permafrost is developed; the overburden conditions are Quaternary aeolian loess distributed on the surface with a thickness of more than 5m and a natural bedrock exposure rate of less than 5%; the mineralization geological conditions are Late Ordovician-Early Silurian crust-mantle mixed granite as the mineralization parent rock, with well-developed northwest-northeast trending fault structures, and identified beryllium mineralization outcrops or mineral occurrences.

[0012] Optionally, the process of conducting geophysical exploration and acquiring geophysical data includes: using a proton magnetometer to perform high-precision magnetic measurements and acquire magnetic measurement data; using an induced polarization profiler to perform induced polarization measurements and acquire induced polarization profile data, including but not limited to apparent resistivity and apparent polarizability; using a controlled-source audio-frequency magnetotelluric sounding method to conduct electrical structure detection and acquire CSAMT data; wherein the CSAMT operates at a frequency of 2–8 kHz, the electrode grounding method uses salt solution enhanced grounding, and the receiving electrode is buried at a depth penetrating the active layer of the permafrost.

[0013] Optionally, the process of obtaining geochemical data by conducting geochemical sampling through thick loess cover layers includes: taking soil samples with a sampling depth of 20-50 cm as the target of penetrating the Quaternary aeolian loess layer on the surface, and conducting tests and analyses using Sn, Be, Li, Nb, Ta, Rb, Cs, and F as a combination of indicator elements.

[0014] Optionally, in the combined indicator element set, Sn, Be, Li, Nb, and Ta are the main ore-forming element group, used to directly indicate the ore-bearing rock mass; Rb, Cs, and F are the alteration indicator element group, used to indicate the differentiation and evolution of granite magma and the degree of hydrothermal alteration; when the Be element content exceeds 3 times the regional background value, and Rb, Cs, and F simultaneously show combination anomalies, it is determined to have beryllium exploration potential.

[0015] Optionally, the process of multi-source remote sensing data acquisition and alteration interpretation includes: acquiring satellite images with a resolution of no more than 2m and UAV images with a resolution of no more than 0.5m, identifying linear fault structures and ring rock mass structures, and marking the intersection of the two sets of faults; using hyperspectral technology to quantitatively extract alteration information of sericitization and chloritization, and generating remote sensing alteration thematic layers.

[0016] Optionally, in the weighted overlay fusion, the weight of the geological data is 30%, the weight of the geophysical data is 25%, the weight of the geochemical data is 25%, and the weight of the remote sensing alteration data is 20%.

[0017] Optionally, the weighted superposition and fusion process includes: First-level fusion: The contact zones of rock masses and the intersections of faults in the geological data are assigned a weight of 30%, and the geophysical data is assigned a weight of 25%, to generate a geological favorability layer and a geophysical anomaly layer, respectively. Secondary fusion: The Be anomaly region and the Rb-Cs-F combined anomaly region in the geochemical data are assigned a weight of 25%, and the sericitization alteration anomaly region and the chloritization alteration anomaly region in the remote sensing alteration data are assigned a weight of 20%, to generate a geochemical anomaly layer and a remote sensing alteration layer, respectively. Three-level fusion: The geological favorability layer, the geophysical anomaly layer, the geochemical anomaly layer, and the remote sensing alteration layer are weighted and overlaid in the GIS platform to generate a comprehensive anomaly distribution map.

[0018] Optionally, the classification of prospecting target areas based on the comprehensive anomaly distribution map includes: designating areas with overlapping geological anomalies, geophysical anomalies, geochemical anomalies, and remote sensing alteration anomalies as Class A priority verification target areas; and designating areas with only one or two types of anomalies and weak superposition intensity as Class B reserve exploration target areas.

[0019] Optionally, the engineering verification includes: deploying shallow-hole drilling and surface trenches with a depth of no more than 200m in the Class A priority verification target area to obtain data on the thickness and extension continuity of the ore-bearing pegmatite vein, and testing the ore grade according to the industrial index of BeO content of no less than 0.06%.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects: This invention ensures the applicability of its method by determining whether the exploration area simultaneously meets three criteria: high-altitude permafrost topography, thick loess cover, and specific mineralization geological conditions. This avoids the blind application of technical methods in inapplicable areas. By limiting the CSAMT operating frequency (2–8 kHz) and adopting a salt solution-enhanced grounding method, it effectively overcomes the shielding interference of the permafrost layer on electromagnetic signals, obtaining clear underground electrical structure data. By setting the sampling depth to 20–50 cm to penetrate the loess layer and combining the joint testing of the main ore-forming element group (Be, Sn, Li, Nb, Ta) with the alteration indicator element group (Rb, Cs, F), the geochemical anomaly signals can accurately reflect deep mineralization information, overcoming the deficiency of insufficient representativeness in shallow sampling. By establishing a quantitative weighted fusion model with 30% geological data, 25% geophysical data, 25% geochemical data, and 20% remote sensing data, the four independent data types are superimposed at multiple levels in a GIS platform with fixed weights. This eliminates the ambiguity of single geophysical anomalies and the subjective bias of human experience-based weighting, making the generation of comprehensive anomaly distribution maps repeatable and objective. By designating highly overlapping areas of the four anomalies as Class A priority verification target areas and deploying shallow-hole drilling, precise deployment of exploration projects is achieved, reducing ineffective drilling work from the source. The entire method quantifies and defines the technical parameters and operating rules of each step, forming a standardized and replicable exploration operation system that can be directly applied to the exploration of granite pegmatite-type beryllium deposits in similar high-altitude loess-covered areas. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of a multi-source collaborative exploration operation according to an embodiment of the present invention; Figure 2 This is a simplified diagram of multi-source information overlay according to an embodiment of the present invention; Figure 3 This is a simplified geological map of Datouyang Xigou, an embodiment of the present invention. Figure 4 This is a cross-sectional diagram (geochemical exploration) of the Erlikenda GA13 anomaly according to an embodiment of the present invention. Figure 5 This is a cross-sectional view of the apparent resistivity of the Erlikon 00 AMT according to an embodiment of the present invention. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0024] Example 1 like Figure 1 As shown in this embodiment, a collaborative exploration method for post-magmatic hydrothermal beryllium deposits in high-altitude permafrost and thick loess-covered areas is provided. Targeting post-magmatic hydrothermal beryllium deposits in high-altitude permafrost and thick aeolian loess-covered areas, the method is divided into four main implementation stages: preliminary data review and work area preparation, simultaneous multi-method field exploration, multi-source data fusion analysis, and target area engineering verification. Each stage is interconnected, and the specific implementation content includes: Phase 1: Preliminary data collection, geological modeling, and field preparation; This stage forms the foundation for the entire process and is divided into three parts: data integration, spatial database construction, and preparation for high-altitude operations. 1. Systematically organize geological data across the entire region; Comprehensive data on stratigraphy, fault structures, and magmatic bodies, along with historical exploration findings, were collected throughout the exploration area. The lithological assemblage, thickness variations, and spatial boundaries of each stratigraphic unit were clarified. The types, occurrences, and activity periods of fault structures were determined. The spatial distribution, intrusion dates, and petrochemical characteristics of granites and granite pegmatites were analyzed, clarifying the spatiotemporal relationship between magmatic activity and beryllium mineralization. Simultaneously, data on the spatial coordinates, orebody size, mineral assemblage, and ore grade of beryllium deposits and mineralized outcrops throughout the area were collected.

[0025] 2. Spatial database construction; Based on the unified coordinate system of the GIS platform, all geological data and mineralization information are entered into the system to construct a dedicated geological database with spatial attributes, and to initially delineate mineralization potential zones.

[0026] 3. Special preparations for high-altitude field operations; In response to the high altitude, permafrost, and strong winds in the work area, the following adjustments were made to the instruments to adapt to high altitudes: high and low temperature calibration was performed on the magnetometer, gravimeter, and electrical resistivity equipment; all positioning equipment was uniformly calibrated; special training was conducted on construction in permafrost areas, green exploration, and field safety; and sampling and wiring operation specifications for loess-covered areas were formulated.

[0027] Phase Two: Simultaneous Field Exploration Using Multiple Technologies; This phase involves three simultaneous tasks: geophysical exploration, geochemical sampling in thick loess areas, and multi-source remote sensing data acquisition and interpretation. These three tasks are conducted independently, with data aggregated synchronously. 1. Integrated geophysical exploration adapted to permafrost; Taking into account the differences in physical properties of beryllium minerals, ore-bearing lithology, and surrounding rocks, a combination of high-precision magnetic surveying, induced polarization gradient measurement, and controlled-source audio-frequency magnetotelluric sounding (CSAMT) was employed. All survey networks and points were flexibly deployed based on topography and permafrost distribution. (1) High-precision magnetic survey: a proton magnetometer with an accuracy of ≥ ±5nT is selected. Before the operation, the base point is corrected and the survey line is laid out perpendicular to the geological body (line spacing 50~100m, point spacing 5~10m). Magnetic interference bodies are eliminated through data processing such as polarization and extension, and the boundary of the granite body is delineated.

[0028] (2) Induced polarization gradient measurement: A high-power induced polarization instrument with an input impedance ≥100MΩ is used. The gradient profile device is used to observe point by point along the survey line to obtain the actual measured data of apparent polarizability and apparent resistivity. The topography, electrode coupling and electromagnetic coupling corrections are completed. Based on the amplitude and gradient characteristics of the induced polarization anomaly, the fracture structure, mineralization alteration zone and the spatial distribution of the concealed ore body are inferred.

[0029] (3) CSAMT detection: The operating frequency of the equipment is limited to 2~8kHz (to adapt to the electromagnetic environment of the plateau). At a scale of 1:10,000, the line spacing is 200~500m and the point spacing is 20~50m. The electrode grounding method is optimized to adapt to the permafrost layer. The underground electrical structure is analyzed and the low-resistivity corrosion zone is delineated.

[0030] This exploration comprehensively employed three geophysical methods—high-precision magnetics, induced polarization gradient measurement, and controlled-source audio-frequency magnetotelluric sounding (CSAMT)—to conduct three-dimensional exploration. The instruments, equipment, construction techniques, and technical parameters for each method are detailed below: (a) High-precision magnetic measurement work; 1) Use instruments; The proton magnetometer is used to conduct high-precision ground magnetic surveys across the entire area. The instrument has the characteristics of automatic diurnal variation correction, high sensitivity, and stable operation at low temperatures, making it suitable for working environments in high-altitude and cold fields and permafrost areas.

[0031] 2) Working methods; Continuous observations are conducted according to the designed survey lines and survey point grids; fixed diurnal variation observation stations are set up simultaneously in the field to collect geomagnetic diurnal variation data in real time throughout the process for subsequent magnetic measurement data correction; the positioning accuracy of survey points and the height of probes above the ground are strictly controlled to reduce topographic and shallow surface magnetic interference; all survey point data are automatically stored, and initial inspection is completed on site to remove jump and interference abnormal data to form the original magnetic measurement dataset.

[0032] 3) Achieve results; High-precision geomagnetic raw observation data for the entire region are used to delineate the boundaries of magnetic rock masses, fault structures, and concealed intrusive bodies.

[0033] (b) Measurement of induced polarization gradient; 1) Use instruments; A high-power time-domain induced polarization (IP) instrument was used to conduct IPE gradient profile measurements. The instrument has high input impedance, stable power supply, and good anti-interference performance, making it suitable for long-distance continuous profile observation in mountainous permafrost areas.

[0034] 2) Working methods; The survey lines and electrode devices were laid out strictly in accordance with the induced polarization gradient specifications. GPS coordinates and elevation data were collected synchronously at each measuring point for topographic, electromagnetic coupling, and device coefficient correction. Repeated observation points were set up for each profile to verify data accuracy. The effects of permafrost, topography, and human interference were recorded on site, and preliminary data preprocessing was completed.

[0035] 3) Achieve results; Original and corrected profile data of apparent resistivity and apparent polarizability for the entire region; using electrical differences to distinguish between surrounding rocks, mineralized rock masses and tectonic fracture zones, and to infer the planar distribution of fault structures, concealed ore-bearing rock masses and mineralized alteration zones.

[0036] (c) Controlled-source audio magnetotelluric sounding (CSAMT) electrical sounding; 1) Use instruments; The complete controllable source audio magnetotelluric sounding system includes a high-power transmitter, a multi-channel receiver, power supply electrodes, receiving electrodes, and high-precision electric and magnetic field sensors.

[0037] 2) Technical parameters; Operating transmission frequency range: 2–8 kHz, taking into account the needs of shallow strata and medium-deep structural electrical stratification detection.

[0038] 3) Electrode grounding construction technology (specifically for frozen soil areas): The work area contains perennial permafrost and seasonally active permafrost. Conventional grounding methods are prone to problems such as excessive grounding resistance and weak signal. This project adopts a salt solution enhanced grounding technology: The excavation of the receiving electrode points is deepened, and the burial depth penetrates the active layer of the frozen soil layer and reaches the lower unfrozen soil layer to ensure that the electrode is in full contact with the moist strata. Saturated salt solution is continuously poured into the electrode pit to reduce grounding resistance, reduce contact impedance interference, and improve the quality of electric field signal acquisition. The power supply electrodes are synchronously grounded by immersion in salt solution, ensuring stable and uniform transmitted signals.

[0039] 4) Working methods; Transmitting dipoles and receiving arrays are set up along the survey line to collect electric and magnetic field components at different frequencies point by point; grounding resistance and signal-to-noise ratio are monitored in real time, and points with substandard grounding are re-excavated and re-measured by pouring salt solution; the distribution of permafrost, topographic undulations, and human interference from pipelines are recorded in real time in the field to provide a basis for subsequent data denoising.

[0040] 5) Achieve results; Using raw electric and magnetic field observation data from CSAMT across the region, resistivity profiles at different underground depths were inverted to analyze the spatial electrical structure of strata, faults, and rock masses.

[0041] 2. Customized geochemical sampling in thick aeolian loess areas; To penetrate the loess and shallow weathered layer, a customized combination of elemental indicators and sampling specifications were developed: (1) Characteristic element combination: The main ore-forming elements Be, Sn, Li, Nb, Ta + alteration indicator elements Rb, Cs, F are used to accurately trace the ore-bearing granite.

[0042] (2) Soil sample collection: The sampling density is set according to the survey scale. For a scale of 1:10,000, there are 4 to 8 points / km², and for a scale of 1:50,000, there are 1 to 2 points / km². The sampling depth is strictly controlled at 20 to 50 cm to ensure that the loess cover layer is penetrated. The weight of a single sample is not less than 500g.

[0043] (3) Sampling of sediments in the water system: Sampling points are set up every 1-2 km in the main water system and every 0.5-1 km in the tributary water system. The weight of a single sample is ≥1000g. All samples are uniformly numbered, packaged and sent for testing. The elemental anomaly zone is delineated according to the test results.

[0044] 3. Multi-source remote sensing data acquisition and detailed analysis of alteration; By integrating high-resolution satellite imagery and low-altitude UAV aerial survey data, interpretation was carried out from three dimensions: structure, rock mass, and alteration. Using GF-2 satellite imagery with a resolution of ≤2m and UAV imagery with a resolution of ≤0.5m, linear faults and ring-shaped rock mass structures were identified, and favorable mineralization sites where two sets of faults intersect were highlighted. Hyperspectral technology was used to quantitatively extract information on beryllium ore-associated alteration such as sericitization and chloritization, quantify the alteration intensity, and generate remote sensing thematic layers.

[0045] Phase 3: Weighted fusion of multi-source data and target classification for exploration; After all field data is collected, data standardization, weighted overlay, and target area delineation are carried out using a GIS platform: 1. Data standardization processing: Format conversion and coordinate registration are performed on four types of data: geological, geophysical, geochemical, and remote sensing data to eliminate systematic errors from different data sources.

[0046] 2. Weighted Fusion Analysis: A fixed-weight model is used for overlay analysis, with geological data weighted at 30%, geophysical data at 25%, geochemical data at 25%, and remote sensing data at 20%. This automatically generates a comprehensive anomaly distribution map covering the entire region, such as... Figure 2 As shown.

[0047] 3. Target area classification; Grade A priority verification target area: located in the granite contact zone, the soil Be element content exceeds the regional background value by 3 times or more, CSAMT shows continuous low resistivity anomaly, and remote sensing interpretation shows significant alteration. The four types of anomalies highly overlap, making it a priority area for engineering deployment.

[0048] Class B reserve exploration target areas: These areas have only one or two prominent anomaly features, and the anomaly superposition effect is weak. They are designated as areas for subsequent supplementary exploration.

[0049] Phase Four: Targeted Engineering Verification and Results Verification; For the Class A target area, shallow engineering was deployed to carry out empirical work: a combination of shallow hole drilling with a depth of ≤200m and surface trenching was used to measure the thickness and continuity of the ore-bearing pegmatite vein; the ore grade was tested according to industrial indicators (BeO≥0.06%), and the industrial value of the ore body was finally determined to form a complete exploration result.

[0050] Example 2 This embodiment provides a method for exploring post-magmatic hydrothermal beryllium deposits in loess-covered areas of plateau permafrost regions, comprising the following steps: ① Application condition determination: The exploration area is determined to meet the following three conditions simultaneously: (a) Geomorphological conditions: plateau mountainous terrain, altitude ≥3500m, seasonal or permanent permafrost; (b) Overburden conditions: Quaternary aeolian loess distributed on the surface, overburden thickness >5m, natural bedrock exposure rate <5%; (c) Mineralization geological conditions: Late Ordovician-Early Silurian crust-mantle mixed granite as the mineralization parent rock, NW-NE trending fault structures developed, beryllium mineralization outcrops or mineral occurrences identified. ② Pre-calibration of permafrost adaptability parameters: Before the start of field operations, the magnetic field instrument, electrical field instrument, and CSAMT transmitter and receiver equipment are calibrated for high-altitude environment adaptability. The calibration content includes: zero-point drift correction of the magnetic field instrument, electrode impedance adaptation calibration of the induced polarization gradient instrument, and high-altitude electromagnetic background noise test and optimization in the range of 2~8kHz for CSAMT transmission frequency. ③ Penetrating sampling of thick loess cover layer: In the area covered by Quaternary aeolian loess, the sampling depth is set at 20~50cm with the goal of penetrating the loess layer. Soil samples are collected and tested and analyzed using Be, Sn, Li, Nb, Ta, Rb, Cs and F as a combination of indicator elements. ④ Geophysical parameter optimization detection in permafrost areas: Controlled source audio magnetotelluric sounding (CSAMT) is used for detection, with its working frequency limited to 2~8kHz. Salt solution enhanced grounding is used for electrode grounding to overcome the high-resistivity shielding effect of the permafrost layer. The receiving electrode is buried at a depth that penetrates the active layer of the permafrost layer. ⑤ Weighted fusion of multi-source exploration data: Geological data (weight 30%), geophysical data (weight 25%), geochemical data (weight 25%), and remote sensing data (weight 20%) are standardized and weighted in a GIS platform to generate a comprehensive anomaly distribution map; ⑥ Target delineation and engineering verification: Based on the comprehensive anomaly distribution map in step ⑤, the areas with high overlap of the four types of anomalies are classified as Class A priority verification target areas, and shallow hole drilling with a depth ≤200m is carried out for verification.

[0051] In one embodiment of this example, in step ③, the sampling depth of the soil geochemical sample is set to 20~50cm. The sampling depth is adjusted according to the thickness of the loess cover layer in the region. The quality standard is that the sample collection location penetrates the surface loess layer and enters the residual slope layer or weathered layer. In areas where the loess cover thickness is ≤50cm, the standard is to penetrate the loess layer. In areas where the loess cover thickness is >50cm, the sampling depth is fixed at 50cm, and the actual thickness of the loess layer is recorded for subsequent anomaly correction.

[0052] In one embodiment of this example, the combination of joint indicator elements in step ③ is further subdivided into: ① Main ore-forming element group: Be, Sn, Li, Nb, Ta, used to directly indicate ore-bearing rock masses; ② Alteration indicator element group: Rb, Cs, F, used to indicate the differentiation and evolution of granitic magma and the degree of hydrothermal alteration; When the Be element content exceeds three times the regional background value, and Rb, Cs, and F simultaneously exhibit abnormal combinations, it is determined to have beryllium ore prospecting potential.

[0053] In one embodiment of this invention, the operating frequency of the Controlled Source Audio Magnetotelluric Sounder (CSAMT) is optimized to 2~8kHz to adapt to the electromagnetic signal propagation characteristics of plateau regions.

[0054] In one embodiment of this example, the multi-source data weighted fusion in step ⑤ is performed according to the following hierarchical fusion rules: ① First-level fusion: The rock mass contact zone and fault intersection in the geological data are assigned a weight of 30%, and the CSAMT low resistivity anomaly zone and magnetic high magnetic anomaly zone in the geophysical data are assigned a weight of 25%, respectively generating a geological favorable layer and a geophysical anomaly layer; ② Secondary fusion: The Be anomaly area (more than 3 times the background value) and the Rb-Cs-F combined anomaly area in the geochemical data are assigned a weight of 25%, and the alteration anomaly area (sericification and chloritization) in the remote sensing data is assigned a weight of 20%, and geochemical anomaly layer and remote sensing alteration layer are generated respectively. ③ Three-level fusion: All four layers are weighted and overlaid in the GIS platform (weight ratio 30:25:25:20) to generate a comprehensive anomaly distribution map; The weighting of 30:25:25:20 is determined by the analytic hierarchy process (AHP) based on the exploration data of three explored mining areas (Datouyang Xigou, Erlikendagou East, and Yama) in the South Qilian metallogenic belt, and then optimized through cross-validation.

[0055] This invention optimizes the entire exploration process for the unique exploration environment of the South Qilian Mountains, characterized by high altitude, permafrost development, and thick aeolian loess cover. Compared with traditional single exploration methods and conventional combination schemes, it has five major practical advantages: 1. Excellent adaptability to high-altitude and cold plateau scenarios: This invention specifically optimizes sampling depth, geophysical instrument operating parameters and field construction methods to address the interference characteristics of permafrost and thick loess layers, effectively solving the problem of traditional exploration techniques being unsuitable for these special areas.

[0056] 2. Significantly improved accuracy in detecting concealed beryllium ore bodies: By building an overall structural framework based on regional geological results, using geophysical methods to detect deep underground geological bodies, using geochemistry to capture surface element anomalies, and combining remote sensing technology to delineate the scope of structures and alterations, the complementary and coordinated use of multiple technologies significantly improves the positioning accuracy of underground concealed beryllium ore bodies and deep pegmatite veins.

[0057] 3. Significantly reduce overall investment in plateau exploration: By relying on a multi-source data weighted fusion model to accurately narrow the exploration scope, blind drilling projects are reduced from the outset. In high-altitude areas with inconvenient transportation, overall construction costs can be reduced by more than 40%, while improving the efficiency of field operations.

[0058] 4. Standardized technical system and can be promoted in different locations: This invention establishes a quantitative multi-source data weighted fusion rule, abandoning the traditional subjective analysis mode that relies on the experience of operators. The entire set of operation process, technical parameters and judgment standards are clear and standardized, and can be directly applied to the exploration of granite pegmatite type beryllium deposits in similar high-altitude loess covered areas in China.

[0059] 5. Reduce the entire exploration cycle: By adopting a multi-process synchronous operation + automated data fusion analysis mode, favorable mineralization sections can be quickly screened. Compared with the traditional step-by-step exploration mode, the overall work cycle can be shortened by more than 50%.

[0060] This method has been piloted in the South Qilian metallogenic belt, the Qaidam Mountain complex rock mass area, and the three major mining areas of Datouyang Xigou, Erkendagou East, and Yama. A total of 30km of geophysical exploration lines and 500 geochemical samples have been completed, and the mining results have been good, which confirms the practicality of this method.

[0061] In the Datouyang Xigou mining area, firstly, a route geological survey was used to delineate the structural zones and rock mass contact zones on the surface; secondly, a 1:25,000 scale hydrographic survey (geochemical exploration) was used to delineate the GA2-SnF composite anomaly, narrowing the prospecting area. The anomaly characteristic parameters are shown in Table 1; thirdly, a 1:5000 scale induced polarization (IP) profile was used to delineate four mineralized IPI anomaly zones. These anomalies exhibit high resistivity, medium polarization, and sawtooth electrical characteristics. The overlay map of the geological and IPI data for the Datouyang Xigou mining area is shown below. Figure 3 As shown, the distribution characteristics of the strata, granite body, fault structures, and quartz veins in the mining area are displayed. Multiple induced polarization (IP) gradient profiles are arranged within the area, displaying apparent polarizability and apparent resistivity curves. Combined with electrical characteristics, the comprehensive IPI anomalies M1, M2, M3, and M4 are delineated. The IPI anomalies are concentrated along the fault alteration zone, quartz veins, and rock mass contact zone. The geological mineralization information and geophysical electrical anomalies are well spatially coupled, which is used to delineate the target area for concealed ore bodies. Fourth, trenching work is carried out in areas where geophysical and geochemical anomalies are well superimposed, revealing industrial ore bodies. Finally, AMT (audio-frequency magnetotelluric) sounding is used to analyze the deep structure, effectively removing interference from the 20-30m Quaternary low-resistivity overburden and distinguishing the high-resistivity layers in the deep granite bedrock. At the same time, multiple high-resistivity trap structures within the bedrock are identified. Later, drilling projects confirm that the ore body is hosted in two high-resistivity trap contact zones, achieving coordinated exploration of shallow anomaly delineation and deep mineralization favorable structure location.

[0062] Table 1 In the Erlikenda mining area, firstly, through surface geological tracing, favorable mineralization geological elements such as ore-controlling structural zones and intrusive contact zones were identified. Secondly, 1:25,000 stream sediment geochemical surveys were conducted to delineate the GA13 comprehensive geochemical anomaly, which is characterized by its large scale, significant intensity, clear concentration center, and complete multi-element aggregation. The parameter characteristics of the Erlikenda GA13 anomaly are shown in Table 2. Figure 4 This is the profile map of the Erlikenda GA13 anomaly, also known as the isopleth map of multi-element soil geochemical anomalies in the Erlikenda mining area. The upper left corner shows a simplified geological structural baseline map, sequentially displaying graded geochemical anomalies of Sn, Bi, F, Be, U, Rb, W, and Th. Each element is characterized by graded color-coding of isopleths to represent concentration zones. Ore-forming elements and associated indicator elements are concentrated and superimposed along fault alteration zones, visually presenting the geochemical ore-controlling patterns of the mining area, used to delineate comprehensive geochemical prospecting target areas for hydrothermal mineralization. This anomaly is characterized by a combination of medium- and high-temperature ore-forming elements, and its spatial distribution is controlled by both intrusive rock masses and fault structures. Thirdly, induced polarization and CSAMT geophysical exploration methods are used to precisely locate favorable sections of the anomaly. The Erlikenda 00 AMT apparent resistivity profile is shown below. Figure 5 As shown, contour lines are used to represent the vertical distribution of apparent resistivity at depth, which is used to verify the mineralization properties of electrical anomalies and provide deep electrical basis for multi-source geological joint deep mineral exploration. Finally, through shallow drilling engineering verification, multiple tin-beryllium industrial ore bodies were delineated in the comprehensive anomaly area.

[0063] Table 2 In summary, this multi-technology joint exploration scheme can overcome the detection interference caused by thick surface cover in the mining area, efficiently locate granite alteration ore bodies, and has achieved good mineral exploration results in the exploration practice of Datouyang Xigou mining area, proving that this method is applicable to the exploration of granite minerals covered by thick loess in plateau areas.

[0064] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in areas covered by thick loess and permafrost in plateau regions, characterized in that, Includes the following steps: Obtain geological data of the exploration area, construct a geological database with spatial attributes based on the geological data, and delineate mineralization potential zones based on the geological database; Within the mineralization potential zone, geophysical exploration will be carried out simultaneously to obtain geophysical data, geochemical sampling will be conducted to penetrate the thick loess cover layer to obtain geochemical data, and multi-source remote sensing data will be collected and alteration interpretation will be performed to obtain remote sensing alteration data. The geological data, geophysical data, geochemical data, and remote sensing alteration data are standardized, weighted, and overlaid in a GIS platform to generate a comprehensive anomaly distribution map. Based on the comprehensive anomaly distribution map, prospecting target areas are classified into different levels, and engineering verification is carried out on the classified prospecting target areas.

2. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, Before obtaining geological data for the exploration area, the application conditions must be determined, and the exploration area must simultaneously meet the geomorphological conditions, overburden conditions, and mineralization geological conditions. The topographic conditions are plateau and mountainous terrain with an altitude of not less than 3500m, and seasonal or permanent permafrost is developed; the overburden conditions are Quaternary aeolian loess distributed on the surface with a thickness of more than 5m and a natural bedrock exposure rate of less than 5%; the mineralization geological conditions are Late Ordovician-Early Silurian crust-mantle mixed granite as the mineralization parent rock, with well-developed northwest-northeast trending fault structures, and identified beryllium mineralization outcrops or mineral occurrences.

3. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, The process of conducting geophysical exploration and acquiring geophysical data includes: using a proton magnetometer to perform high-precision magnetic measurements and acquire magnetic data; using an induced polarization profiler to perform induced polarization measurements and acquire induced polarization profile data, including but not limited to apparent resistivity and apparent polarizability; and using a controlled-source audio-frequency magnetotelluric sounding method to conduct electrical structure detection and acquire CSAMT data. The CSAMT operates at a frequency of 2–8 kHz, and the electrode grounding method uses salt solution enhanced grounding, with the receiving electrode buried at a depth penetrating the active layer of the permafrost.

4. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, The process of obtaining geochemical data by conducting geochemical sampling through thick loess cover includes: taking soil samples with a sampling depth of 20-50 cm as the target to penetrate the Quaternary aeolian loess layer on the surface, and conducting tests and analyses using Sn, Be, Li, Nb, Ta, Rb, Cs, and F as a combination of indicator elements.

5. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 4, characterized in that, In the combined indicator element set, Sn, Be, Li, Nb, and Ta are the main ore-forming element set, used to directly indicate ore-bearing rock masses; Rb, Cs, and F are the alteration indicator element set, used to indicate the differentiation and evolution of granite magma and the degree of hydrothermal alteration; when the Be element content exceeds three times the regional background value, and Rb, Cs, and F simultaneously show combined anomalies, it is determined to have beryllium exploration potential.

6. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, The process of multi-source remote sensing data acquisition and alteration interpretation includes: acquiring satellite images with a resolution of no more than 2m and UAV images with a resolution of no more than 0.5m, identifying linear fault structures and ring rock mass structures, and marking the intersection of the two sets of faults; using hyperspectral technology to quantitatively extract alteration information of sericitization and chloritization, and generating remote sensing alteration thematic layers.

7. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, In the weighted overlay fusion, the geological data has a weight of 30%, the geophysical data has a weight of 25%, the geochemical data has a weight of 25%, and the remote sensing alteration data has a weight of 20%.

8. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 7, characterized in that, The weighted overlay and fusion process includes: First-level fusion: The contact zones of rock masses and the intersections of faults in the geological data are assigned a weight of 30%, and the geophysical data is assigned a weight of 25%, to generate a geological favorability layer and a geophysical anomaly layer, respectively. Secondary fusion: The Be anomaly region and the Rb-Cs-F combined anomaly region in the geochemical data are assigned a weight of 25%, and the sericitization alteration anomaly region and the chloritization alteration anomaly region in the remote sensing alteration data are assigned a weight of 20%, to generate a geochemical anomaly layer and a remote sensing alteration layer, respectively. Three-level fusion: The geological favorability layer, the geophysical anomaly layer, the geochemical anomaly layer, and the remote sensing alteration layer are weighted and overlaid in the GIS platform to generate a comprehensive anomaly distribution map.

9. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 1, characterized in that, The classification of prospecting target areas based on the comprehensive anomaly distribution map includes: areas with overlapping geological anomalies, geophysical anomalies, geochemical anomalies, and remote sensing alteration anomalies are classified as Class A priority verification target areas; areas with only one or two types of anomalies and weak superposition intensity are classified as Class B reserve exploration target areas.

10. The method for collaborative exploration and prospecting of post-magmatic hydrothermal beryllium deposits in thick loess-covered permafrost areas of plateaus according to claim 9, characterized in that, The engineering verification includes: deploying shallow-hole drilling and surface trenches with a depth of no more than 200m in the Class A priority verification target area to obtain data on the thickness and extension continuity of the ore-bearing pegmatite veins, and testing the ore grade according to the industrial index of BeO content of no less than 0.06%.

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