Deep prospecting method for steep-dip-angle thin-vein type gold mine

Abstract

The invention belongs to the field of geological prospecting, and discloses a deep prospecting method for a steep-dip-angle thin-vein gold mine, which is characterized in that in the prior art, comprehensive methods such as geological survey, induced polarization sounding and surface geochemical exploration are mainly adopted for prospecting the gold mine, a prospecting prediction comprehensive information model is constructed, mineralized body abnormity is delineated through mutual verification, and a better prospecting effect is achieved at a shallow position of 500 meters. However, as a traditional combination method for predicting the occurrence position of the ore body has a large error, the prospecting success rate is not high. According to the prospecting method, the wide-area electromagnetic sounding technology is adopted, identification of deep geological information is enhanced, verification is carried out through drilling in the middle and shallow parts, the three are mutually verified, the error of deep prediction of the steep dip angle thin vein type ore body is reduced, the prospecting success rate is increased, and an important reference basis is provided for deep prospecting.

Description

Technical Field

[0001] The present invention belongs to the field of geological prospecting industry, and in particular relates to a deep prospecting method for steep-angle thin-vein gold deposits. Background Art

[0002] Continuous exploration of gold mines is an important task for geologists in my country. There are many types of gold mines, and the difficulty of exploration varies. In particular, the exploration difficulty of steep-angle and thin-vein gold mines is a type of gold mine that is recognized in the industry as having a low exploration success rate.

[0003] Steep-angle, thin-vein gold deposits are defined as gold ore bodies with an output dip greater than 75°, localized reverse dip, and a horizontal width less than 2.0m. These deposits are significantly structurally controlled, with quartz veins being the predominant ore type, followed by fragmented altered rock types, and their dip extension length exceeding the strike extension length. Existing methods for exploring this type of gold deposit shallower than 500 meters primarily utilize a combination of geological mapping, induced polarization sounding, and surface geochemical prospecting. Comprehensive information models for prospecting and prediction are constructed, and through cross-correlation, anomalies in deep mineralization are delineated. However, as the ore body depth increases, the geological properties become more complex, and various interference factors become more pronounced, traditional geophysical and chemical combination methods have limited ability to clearly reflect deep anomaly information in steep-angle, thin-vein gold deposits. This is particularly true when the surrounding rock mass of the ore body is not very diverse, making it difficult to identify its deep characteristics. Consequently, there are significant errors in the predicted location of the ore body, resulting in a low success rate for prospecting. Summary of the Invention

[0004] This invention provides a deep prospecting method for steep-angle, thin-vein gold deposits. This method allows for clearer inversion of deep fault morphology and better prediction of orebody extension characteristics. By corroborating geology, remote sensing interpretation, geophysics, and drilling, it reduces the error in deep predictions for steep-angle, thin-vein ore bodies and improves the success rate of prospecting.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for deep prospecting of steep-angle thin-vein gold deposits, the method comprising the following steps: S1: Collect regional geological data, analyze the mineralization geological background, conduct field geological surveys, and identify the geological characteristics and physical properties of surrounding rocks and fault zones; Remote sensing interpretation is used to interpret surface annular and linear structures, and iron staining and hydroxyl groups are extracted to identify surface mineralization and alteration. Based on the geological background, favorable mineralization areas are selected. S2: Select typical deposits in the favorable mineralization area, collect and analyze the data on the ore body shape, scale and occurrence, and determine the spatial distribution and occurrence pattern of steep-angle thin-vein gold deposits; S3: Using the exploration results of steps S1 and S2, determine the areas related to geological bodies - structures - mineralization alteration associated with gold mineralization. Use the wide - area electromagnetic sounding geophysical instrument to determine the line spacing and layout principles of the survey lines, conduct geophysical surveys, draw profile contour maps, and determine the deep morphology of faults. S4: Use drilling engineering to identify the anomalies of shallow alteration zones on the geophysical contour lines. The shallow part is within 500 meters. Adjust the parameters to form a more refined geophysical inversion map, accurately indicate the deep extension of the ore - controlling faults. The deep part is beyond 1500 meters. Furthermore, delineate the spatial occurrence positions of gold ore bodies and construct a geological - remote sensing interpretation - geophysics - drilling exploration model. S5: In the favorable ore - forming areas, carry out prospecting prediction using the "exploration model" obtained in step S4 and delineate deep - prospecting target areas.

[0006] Preferably, in step S1, the remote - sensing interpretation process uses ASTER and GF - 1 satellite remote - sensing data to interpret circular structures and linear structures, and delimits the prospecting far - reaching areas by synthesizing ore - forming information.

[0007] Preferably, the remote - sensing interpretation process uses ASTER - B631 and GF - 1 - B431 remote - sensing image data to interpret faults, ductile shear zones, and circular structures in the area.

[0008] Preferably, the delimited prospecting far - reaching areas are gold - mineralization far - reaching areas divided according to the information such as the faults, circular structures interpreted by remote sensing, the distribution characteristics, scales of faults, and the distribution characteristics, scales, and intensities of remote - sensing anomaly concentration areas, integrating the ore - controlling geological conditions and ore - forming geological characteristics of known gold deposits.

[0009] Preferably, the identification of surface mineralization alteration by extracting iron staining and hydroxyl groups uses the Crosta principal component analysis and ratio method to extract anomalies from ASTER remote - sensing data. Through ASTER data, fine mineral anomaly information of aluminum hydroxyl, magnesium hydroxyl, and iron staining can be extracted.

[0010] Preferably, the wide - area electromagnetic sounding geophysical instrument used in step S3 is divided into two parts: a transmitting system and a receiving system. The transmitting system includes the JSDY series power cabinets and the DNG - 2 multi - function signal controller. The receiving system includes the JSGY - 2 wide - area electromagnetic receiver, which realizes synchronous high - precision acquisition of signals for each channel and real - time displays time - domain waveforms and frequency - domain data.

[0011] Preferably, in step S3, the determination of the line spacing and layout principle of the survey line is as follows: For the deep part of the ore-controlling fault, geophysical prospecting lines are arranged. The azimuth of the survey line is perpendicular to the strike of the fault. The measuring points are selected in open and flat terrain, avoiding mountaintops, narrow deep gully bottoms or rocky outcrops. The ratio of the relative height difference between the two poles to the pole distance should not be greater than 10%. The electrode position is far from the interference source. When selecting points, it is considered that the surface soil quality within the pole layout range is uniform, and the point cannot be set beside an obvious local non-uniform body.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By adopting the deep gold ore prospecting method of the present application, especially the application of the wide-area electromagnetic sounding technology, the identification of deep geological information is strengthened, and drilling is used for verification in the shallow and medium depths. The three confirm each other, reducing the error of the deep prediction of steeply inclined thin vein-type ore bodies, improving the success rate of ore prospecting, and providing an important reference basis for deep ore prospecting; 2. The steeply inclined thin vein-type gold ore is significantly controlled by faults. The ore-bearing zone and the ore-controlling fault extend from the shallow part to the deep part in a gentle wave shape, showing the characteristics of pinching out and reappearing. Generally, the ore bodies are more concentrated at the fault bends. With the continuous improvement of remote sensing interpretation and geophysical technologies, the identification ability of faults and mineralization alteration in the covered area is strengthened. Especially the application of wide-area electromagnetic sounding uses technologies with large depth, anti-interference, and high resolution to strengthen the identification of deep geological information. Combined with shallow drilling projects, the deep morphology of the fault is more clearly inverted, and the extension characteristics of the ore body are predicted. Through the mutual confirmation of geology - remote sensing interpretation - geophysics - drilling, the error of the deep prediction of steeply inclined thin vein-type ore bodies can be reduced, and the success rate of ore prospecting can be improved; Through the following detailed description of the exemplary embodiments of the present disclosure with reference to the accompanying drawings, other features and advantages of the present disclosure will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or related technologies. Obviously, the accompanying drawings in the following description are only the embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0014] Figure 1 It is a flowchart of the deep gold ore prospecting method for steeply inclined thin vein-type gold ore of the present invention; Figure 2 It is a comprehensive remote sensing interpretation information map of the Jinqingding area in step S1 of the embodiment of the present invention; Figure 3 It is a remote sensing anomaly extraction and on-site feature comparison map in step S1 of the embodiment of the present invention, where (a) is the Tangjiagou area and (b) is the Yinggezhuang area; Figure 4This is a map of newly discovered gold ore spots in the remote sensing gold metallogenic prospective area of step S1 of the embodiment of the present invention. Among them, (a) is the Hulongtou area, and (b) is the Moshan area; Figure 5 This is a simplified geological structure diagram of the Jinqingding ore section in the Mouru metallogenic belt for analyzing the typical ore deposits in step S2 of the embodiment of the present invention; Figure 6 This is a geophysical inversion map - deep exploration map (profile contour map) of the wide - area electromagnetic sounding method (WFEM) of line GY1 in the Jinqingding area in step S4 of the embodiment of the present invention. Specific embodiments

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0016] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the sake of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0017] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "upper" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in a drawing is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "beneath" the other device or structure. Thus, the exemplary term "above" can include both the "above" and "below" orientations. The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0018] See also Figures 1-6 The present invention provides a technical solution: a method for deep prospecting of steep-angle thin-vein gold deposits, the prospecting method comprising the following steps: S1: Collect regional geological data, analyze the mineralization geological background, conduct field geological surveys, and identify the geological characteristics and physical properties of surrounding rocks and fault zones; Remote sensing interpretation is used to interpret surface annular and linear structures, and iron staining and hydroxyl groups are extracted to identify surface mineralization and alteration. Based on the geological background, favorable mineralization areas are selected. S2: Select typical deposits in the favorable mineralization area, collect and analyze the data on the ore body shape, scale and occurrence, and determine the spatial distribution and occurrence pattern of steep-angle thin-vein gold deposits; S3: Using the exploration and mining results of steps S1 and S2, determine the geological body, structure, and mineralized alteration areas related to gold mineralization, use wide-area electromagnetic sounding geophysical instruments to determine the line spacing and layout principles of the survey lines, conduct geophysical measurements, draw profile contour maps, and determine the deep morphology of the fault; S4: Use drilling engineering to identify anomalies in shallow alteration zones on geophysical contour lines. Areas within 500 meters are considered shallow. Adjust parameters to form more detailed geophysical inversion maps, accurately indicating the extension of ore-controlling faults at depth. Areas beyond 1,500 meters are considered deep. This allows the spatial location of gold deposits to be delineated, and a geological-remote sensing interpretation-geophysical-drilling exploration model is constructed. S5: In the favorable mineralization area, the "exploration model" obtained in step S4 is used to carry out prospecting prediction and delineate deep prospecting target areas.

[0019] The remote sensing interpretation process in step S1 uses ASTER and GF-1 satellite remote sensing data to interpret circular structures and linear structures, and integrates mineralization information to delineate prospecting areas.

[0020] In step S1, the remote sensing interpretation process uses ASTER-B631 and GF-1-B431 remote sensing image data to interpret the faults, ductile shear zones and annular structures in the area.

[0021] The prospecting areas are delineated based on the information of faults, annular structures and distribution characteristics, size of faults interpreted by remote sensing, as well as the distribution characteristics, size and intensity of remote sensing abnormal concentration areas, combined with the ore-controlling geological conditions and metallogenic geological characteristics of known gold deposits.

[0022] In step S1, iron staining and hydroxyl are extracted to identify surface mineralization and alteration. The ASTER remote sensing data is subjected to anomaly extraction using Crosta principal component analysis and ratio method. The ASTER data can be used to extract subtle mineral anomaly information of aluminum hydroxyl, magnesium hydroxyl and iron staining.

[0023] The wide-area electromagnetic sounding geophysical instrument used in step S3 is divided into two parts: a transmitting system and a receiving system; the transmitting system includes a JSDY series power cabinet and a DNG-2 multi-function signal controller; the receiving system includes a JSGY-2 wide-area electromagnetic receiver, which realizes synchronous high-precision acquisition of signals from each channel and displays time domain waveforms and frequency domain data in real time.

[0024] In step S3, the line spacing and layout principles of the survey line are determined as follows: for the deep-lying physical detection line of the ore-controlling fault, the survey line orientation is perpendicular to the fault direction, and the survey points are selected in open and flat areas, avoiding mountain tops, narrow deep gully bottoms, or exposed rocks. The ratio of the relative height difference between the two poles to the pole spacing should not be greater than 10%; the electrode position is far away from the interference source, and the point selection takes into account the uniformity of the surface soil within the pole layout range. The points cannot be set next to obvious local inhomogeneous bodies. Example:

[0025] Step S1: Determine the spatial distribution of mineralization-related Late Jurassic monzogranite, north-northeast-trending fault zones, and pyrite, silicification, and carbonatization along these faults within the Muping-Rushan gold metallogenic zone in Jiaodong. Geological and mineral resource surveys are conducted in areas with north-northeast-trending ore-controlling faults or pyrite-bearing quartz veins with a dip greater than 75° and a width less than 2.0 m. The Jurassic Linglong monzogranite is a low-polarization, high-resistivity body with an average resistivity range of 2500-6000 Ω·m and an average polarizability range of 2%-5%. The fault structural zone is a highly polarizable, steeply dipping, tabular, low-resistivity body with an average resistivity range of 300-2000 Ω·m and an average polarizability range of 4%-8%. The ore bodies are highly polarizable, steeply dipping, tabular, low-resistivity bodies with an average polarizability range of 2%-20%.

[0026] In the Jiaodong region, pyrite quartz vein-type gold deposits are concentrated in the Mouru metallogenic belt. The dip angle of the ore bodies ranges from 70° to 90°, and the horizontal width is less than 2 m. The ore-hosting wall rock is mainly Mesozoic Linglong granite. There is no obvious density difference between the hanging wall and footwall wall rocks. It is also difficult to reflect the small density difference between the fracture zone and the gold-bearing quartz vein in it and the wall rock in the gravity anomaly reflecting the volume effect. Therefore, it is impossible to directly delineate this type of gold deposit using gravity exploration. Since the fracture structures hosting this type of gold deposit have a certain scale, fracturing and alteration are generally developed, and due to the relatively high sulfide content, obvious induced polarization anomalies can be caused. During electrical prospecting, it can be reflected as obvious "low resistivity, high polarization" anomaly characteristics. The amplitude range of the resistivity anomaly is generally 500 - 2000 Ω•m, and it shows high polarization anomaly characteristics higher than the background wall rock in terms of the polarization rate parameter. The amplitude range is between 4% and 7%, and when approaching the vicinity of the ore body, it will reach more than 8%, and in the rich ore section, it can reach more than 20%.

[0027] And in step S1, ASTER and GF-1 satellite remote sensing data are also used. The staff extracts the aluminum-magnesium hydroxyl (Al-OH, Mg-OH) and iron stain anomaly information related to pyritization and sericitization alteration from the remote sensing image map, and conducts on-site surveys. According to the survey results, the anomaly concentration areas are delineated in the arcgis software in combination with the remote sensing image map, and the circular structures and linear structures are interpreted. The linear fractures are mainly manifested as linear color anomalies of different tones or in the form of broadband linear distributions. The NE and NNE fractures are large in scale, long in extension, wide in distribution and numerous in number, manifested as large gullies, steep cliffs, etc. The NW fractures are manifested as NW-linear gullies, arranged steep cliffs, etc. In some local areas, they control the modern topography and show the characteristics of tensional fractures; the ductile shear zones are in the form of dense thin line textures, strip-shaped extensions, with good continuity, showing row-like linear protrusions; the circular structures are mostly radial water systems, circular water systems, water points arranged in a circular pattern, or circular ridges, circular gullies, circular tone anomalies, or near-circular or elliptical geological bodies. Based on the GF-1 and ASTER remote sensing data, structural interpretation is carried out in the study area. 929 linear structures, 89 circular structures and 15 ductile shear zones are interpreted. It is considered that the edge sections of the NNE fractures, circular structures and ductile shear zones are favorable sites for the occurrence of gold deposits. The gold deposits (points) are distributed on the edge of the circular structures or above the NNE fractures. Combining the metallogenic information, the prospecting target areas are delimited. The ENVI software is used to extract, screen and classify the remote sensing anomalies of the remote sensing data, and a 1:50,000 remote sensing anomaly distribution map of the working area is compiled to form a comprehensive remote sensing interpretation information map ( Figure 2 )

[0028] Step S1 also uses the Crosta principal component analysis and the ratio method to extract anomalies from ASTER remote sensing data. Subtle mineral anomaly information such as aluminum hydroxide, magnesium hydroxide, and iron staining can be extracted through ASTER data. The aluminum hydroxide (Al-OH) information is usually related to the altered mineral assemblages such as white (sericite) mica, kaolinite, montmorillonite, and illite. The magnesium hydroxide (Mg-OH) information is usually related to the altered mineral assemblages such as chlorite, epidote, calcite, and dolomite. Iron staining is related to the altered mineral assemblages containing Fe2+ and Fe3+, which is associated with rock limonitization, but not limited to this. 36 anomaly concentration areas are delineated in the whole area. The locations of gold deposits generally develop strong aluminum and magnesium hydroxide anomalies.

[0029] Comprehensive information shows that in the area where late Jurassic monzogranite outcrops, in the areas where NE and NNE trending faults are developed, in the anomaly concentration areas of hydroxyl and iron staining and where concentration centers are developed, it is a favorable area for wall rock alteration, ore-bearing hydrothermal fluid migration, and enrichment of hydrothermal deposits (Tangjiagou Gold Deposit, Yinggezhuang Gold Deposit). See the remote sensing anomaly extraction and field feature map ( Figure 3 ).

[0030] In the areas where circular structures and NNE trending linear faults are developed, and in the anomaly concentration areas of iron staining and hydroxyl. Through field verification, 2 new gold ore points are discovered. See the map of newly discovered gold ore points in the remote sensing gold metallogenic prospective area ( Figure 4 ).

[0031] Among them, 1 new gold mineralization zone is discovered at 1.0 km west of Hulongtou Village, at the intersection of nearly EW and NE trending faults, at the edge of the circular structure, and in the area where aluminum and magnesium hydroxides are developed. The altered zone occurs in a lenticular shape, with an outcrop width of about 2.0 - 5.0 m and an intermittent extension of more than 300 m. 1 gold ore body is delineated inside it, with a width of 3.90 m, and the occurrence , and the gold grade is 3.11×10 -6 . The ore-bearing rock is pyritized silicified cataclastic rock. It weathers to be brownish red, and the fresh surface is grayish green - grayish black. It develops sericitization and pyritization alterations, and pyrite is relatively developed, occurring in disseminated, veinlet, and star-shaped distributions ( Figure 4 a).

[0032] 800 m southwest of Moshan Village, at the edge of the NNE trending fault, circular structure, and in the area of aluminum and magnesium hydroxide anomalies, 1 new gold mineralization zone is discovered. The altered zone occurs in a vein shape, with an outcrop length greater than 500 m and a width of 1.10 - 5.50 m, and the occurrence , and 1 gold ore body is delineated inside it, with a width of 0.30 m, and the gold grade is 3.38×10 -6 . The ore-bearing rock is limonite quartz vein, which develops limonitization, silicification, and sericitization alterations, and lamprophyre veins are seen to be filled ( Figure 4 b).

[0033] Step S2 analyzes typical ore deposits and produces a simplified geological structure diagram of the Jinqingding ore section in the Mouru metallogenic belt ( Figure 5 ). High-precision identification of deep ore-controlling faults is the key. When there are obvious physical property differences between the two sides of the ore-controlling fault, the interface of different geophysical field characteristics formed is the output characteristic of the fault, which can greatly reduce the difficulty of deep detection. When the surrounding rocks on both sides of the fault are of the same lithology or rocks with similar physical property parameters, although there are physical property differences between the gold-bearing tectonic alteration zone and the surrounding rocks, the scale of the ore-controlling fault where the vein-shaped ore deposit is located is generally limited, especially when the depth is large, it is more difficult to identify. Therefore, the detection of deep faults in the single-physical-property surrounding rock scenario is extremely difficult, and the methods used need to meet the two key index requirements of large depth and high precision at the same time. In this study, the Jinqingding Gold Mine in the Mouru metallogenic belt in the eastern part of Jiaodong is selected as a typical ore deposit. The steeply inclined thin vein-type gold ore bodies are significantly controlled by faults. The ore-bearing zone and the ore-controlling fault extend from shallow to deep in a gentle wave shape, showing the characteristics of pinching out and reappearing. Generally, the ore bodies are more concentrated at the fault bends and plunge northeastward.

[0034] In step S3, the wide-area electromagnetic instrument and supporting equipment produced by Hunan Jishan High-Tech Co., Ltd. are used, which can be divided into a transmitting system and a receiving system. The transmitting system is mainly used for the transmission of wide-area signals, including a JSDY series power supply cabinet with a power of 180 kw, which mainly completes the rectification, boosting, voltage regulation and signal inversion of the power supply, with a maximum output voltage of 1000 V and a maximum supply current of 180 A; a DNG-2 multi-functional signal controller, which integrates signal synthesis and measurement, and uses a high-precision clock source and digital signal synthesis technology to ensure the accuracy of the transmitted signal frequency. The receiving system is a JSGY-2 wide-area electromagnetic receiver, which mainly completes the acquisition and data processing of 8-channel electric field signals, has a high measurement efficiency, realizes synchronous high-precision acquisition of signals in each channel, and uses a unique algorithm to screen and process the data to effectively suppress random interference.

[0035] For the deep layout of physical exploration lines for ore-controlling faults, the azimuth of the survey line is perpendicular to the fault strike. The measuring points should be selected in open and flat terrain, avoiding mountaintops, narrow deep gully bottoms or rock outcrops. The ratio of the relative height difference between the two poles to the pole distance should not be greater than 10%; the electrode position should be far from the interference source, and the selection of points should consider the uniform surface soil quality within the pole layout range, and the point position should not be set beside obvious local non-uniform bodies.

[0036] In the pseudo-section characteristics of the wide-area electromagnetic sounding method, the high-resistance characteristics on both sides are the distribution of the late Jurassic medium-coarse grained monzonitic granite rock mass. The Jiangjunshi fault forms a relatively obvious approximately funnel-shaped low-resistance anomaly, which is sandwiched by the high-resistance background fields on both sides. In the profile contour map, there are obvious low-resistance depressions in the ore-controlling fault interval for each isofrequency curve, and the position where the drop is most obvious coincides with the center point position of the low-resistance anomaly in the pseudo-section map. The two initial result maps are highly correlated and coincident, and the local low-resistance anomaly distribution of the Jiangjunshi fault in the single-physical-property surrounding rock environment can be preliminarily extracted.

[0037] Step S4: Shallow drilling engineering verification to accurately determine the fracture position and its deep extension. For the inversion results of the wide-field electromagnetic sounding method (WFEM) ( Figure 6 ), it can be analyzed that: the ore-controlling fractures in Jiangjunshi all show low-resistance anomaly zones against the background of high apparent resistivity, and the low-resistance characteristics of the fractures can be clearly distinguished from the high-resistance surrounding rocks of the Linglong sequence. The WFEM method still shows obvious electrical anomalies in the shallow part below -2500, and the response characteristics of deep fractures show linear beaded low-resistance anomalies, with strong recognition ability for local deep low-resistance bodies.

[0038] Finally, in step S5, a geological-remote sensing interpretation-geophysical-drilling exploration model is constructed and applied to the main ore-controlling fractures in the favorable ore-forming areas, which has good results for deep prospecting. In this project, the predicted gold metal quantity is 416,040 kg.

[0039] Among them, the gold resource quantity of this project is pre-estimated by the volume method, and the resource quantity level is potential mineral resources.

[0040] The scope of resource quantity estimation is the spatial distribution range where the ore-bearing geological body, ore-bearing structure, and alterations related to gold mineralization (such as silicification, limonitization, sericitization, etc.) overlap, that is, the spatial distribution range corresponding to the line-ring structure and iron-stained hydroxyl anomaly in remote sensing interpretation.

[0041] Estimation method: I. Select 1 typical ore deposit as the model area; II. Compare the overall similarity of all prediction elements between the model area and the prediction area. The prediction elements include the degree of geological work, ore-forming conditions, geophysical and geochemical exploration, natural heavy minerals, alterations, mineralization, mineralization zones, etc., and determine the ore-bearing coefficient of the estimation area.

[0042] The volume method of ore-bearing geological body is selected for estimating the predicted resource quantity in the prediction area. Because the potential of a certain mineral resource occurring in a certain geological formation is proportional to this formation, and areas with similar geological formations have similar resource potentials.

[0043] Formula for estimating the predicted resource quantity in the prediction area: Z 预 = S 预 × H 预 × Ks × K × α Z 预 : Predicted resource quantity in the prediction area S 预 : Area of the prediction area H 预 : Depth extension of the prediction area (referring to the depth extension of the ore-bearing geological body in the prediction area) Ks: Area parameter of the ore-bearing geological body K: Ore-bearing coefficient of the ore-bearing geological body in the model area α: Similarity coefficient Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deep prospecting method for steeply inclined thin vein type gold deposits, characterized in that: The prospecting method comprises the following steps: S1: Collect regional geological data, analyze the mineralization geological background, conduct field geological surveys, and identify the geological characteristics and physical properties of surrounding rocks and fault zones; Remote sensing interpretation is used to interpret surface annular and linear structures, and iron staining and hydroxyl groups are extracted to identify surface mineralization and alteration. Based on the geological background, favorable mineralization areas are selected. S2: Select typical deposits in the favorable mineralization area, collect and analyze the data on the ore body shape, scale and occurrence, and determine the spatial distribution and occurrence pattern of steep-angle thin-vein gold deposits; S3: Using the exploration and mining results of steps S1 and S2, determine the geological body, structure, and mineralized alteration areas related to gold mineralization, use wide-area electromagnetic sounding geophysical instruments to determine the line spacing and layout principles of the survey lines, conduct geophysical measurements, draw profile contour maps, and determine the deep morphology of the fault; S4: Use drilling engineering to identify anomalies in shallow alteration zones on geophysical contour lines. Areas within 500 meters are considered shallow. Adjust parameters to form more detailed geophysical inversion maps, accurately indicating the extension of ore-controlling faults at depth. Areas beyond 1,500 meters are considered deep. This allows the spatial location of gold deposits to be delineated, and a geological-remote sensing interpretation-geophysical-drilling exploration model is constructed. S5: Use the "exploration model" obtained in step S4 to carry out prospecting prediction in the favorable mineralization area and delineate deep prospecting target areas.

2. A deep prospecting method for steep dip thin vein type gold deposits according to claim 1, characterized in that: The remote sensing interpretation process in step S1 uses ASTER and GF-1 satellite remote sensing data to interpret circular structures and linear structures, and integrates the mineralization information to delineate prospecting areas.

3. A deep prospecting method for steeply inclined thin vein-type gold deposits according to claim 2, characterized in that: The remote sensing interpretation process in step S1 uses ASTER-B631 and GF-1-B431 remote sensing image data to interpret the faults, ductile shear zones and annular structures in the area.

4. A deep prospecting method for steep dip thin vein type gold deposits according to claim 2, characterized in that: The delineation of the prospective prospecting area is based on the faults, annular structures and fault distribution characteristics, size and distribution characteristics, scale and intensity information of remote sensing abnormal concentration areas, and the gold mineralization prospective area is divided based on the ore-controlling geological conditions and mineralization geological characteristics of known gold deposits.

5. A deep prospecting method for steeply dipping thin vein type gold deposits according to claim 1, characterized in that: In step S1, iron staining and hydroxyl are extracted to identify surface mineralization and alteration, and the abnormality extraction of ASTER remote sensing data is performed using Crosta principal component analysis and ratio method. The subtle mineral abnormality information of aluminum hydroxyl, magnesium hydroxyl and iron staining can be extracted from ASTER data.

6. A deep prospecting method for steep dip thin vein type gold deposits according to claim 1, characterized in that: The wide-area electromagnetic sounding geophysical instrument used in step S3 is divided into two parts: a transmitting system and a receiving system; the transmitting system includes a JSDY series power cabinet and a DNG-2 multi-function signal controller; the receiving system includes a JSGY-2 wide-area electromagnetic receiver, which realizes synchronous high-precision acquisition of signals from each channel and displays time domain waveforms and frequency domain data in real time.

7. A deep prospecting method for steeply inclined thin-vein type gold deposits according to claim 1, characterized in that: In step S3, the determination of the line spacing and layout principle of the survey line is as follows: For the deep part of the ore-controlling fault, geophysical exploration lines are laid out. The azimuth of the survey line is perpendicular to the fault strike. The measuring points are selected in open and flat terrains, avoiding mountaintops, narrow deep gully bottoms or rock outcrops. The ratio of the relative elevation difference between the two poles to the pole distance should not be greater than 10%. The electrode positions are far from interference sources. When selecting points, it is considered that the surface soil quality within the pole layout range is uniform, and the point positions cannot be set beside obvious local non-uniform bodies.

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