Exploration method for constructing altered rock type gold mine in shallow coverage area

Abstract

The invention belongs to the technical field of geological prospecting, and particularly discloses an exploration method for constructing an altered rock type gold mine in a shallow coverage area, which comprises the following steps of: firstly, optimizing a working area by using regional geochemical prospecting abnormity, and gradually reducing a prospecting target area by using 1: 25,000 geochemical measurement, 1: 10,000 soil profile measurement and 1: 10,000 geological grass survey; identifying a linear negative topographic development section by using an unmanned aerial vehicle, quickly positioning a gold-bearing structure alteration zone by using a manner of stripping soil and adopting a detection sample, and performing ground surface control by using a groove exploration project; and a target position is predicted by combining the ore body grade, the ore body thickness and the product contour map of the ore body grade thickness by utilizing a structure superposition halo method, drilling engineering deep verification is carried out, and finally the topography and the landform are recovered to find out the shape, the occurrence, the scale and the resource potential condition of the gold mineralized body. The method is simple and convenient, small in environmental disturbance, low in cost investment and good in coverage area effect, the purpose of rapid prospecting is achieved, and an excellent gold ore prospecting effect is achieved in the Heidong region of the Qieemun Tagean, the cliff and the Qieemun Tagean.

Description

Technical Field

[0001] The invention relates to the technical field of geological prospecting, and in particular to an exploration method for structural alteration rock type gold deposits in shallow overburden areas. Background Art

[0002] The East Kunlun metallogenic belt is an important gold distribution area in Northwest my country, known as the "Golden Belt". The gold deposits in the belt are mainly produced in the eastern section of the East Kunlun Mountains, while no gold mines with prospecting prospects have been found in the Qimantagh area in the western section of the East Kunlun Mountains. In the Mangyahe East mining area, only the bedrock is exposed in the steep terrain of the Central Mountain, and the rest is covered by the Quaternary system, which makes it very difficult to directly find outcrops such as mineralization and alteration clues on the surface, and the direct prospecting efficiency is low. Therefore, how to study a prospecting method for tectonic altered rock type gold deposits that meets the requirements of green exploration in similar shallow coverage areas has become a problem that technicians in this field need to solve urgently. Summary of the invention

[0003] In view of this, the present invention discloses a method for prospecting tectonic altered rock type gold deposits in shallow cover areas. The present invention uses orogenic gold deposit mineralization theory, 1 / 5 water system sediment measurement, 1:25,000 geochemical measurement, soil chemical profile, drone, soil stripping to take reconnaissance samples, trench, drilling engineering and other technologies to gradually narrow the target area, control the gold-bearing target body, and improve the success rate of prospecting.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A method for prospecting for structurally altered rock type gold deposits in shallow overburden areas comprises the following steps:

[0006] Step 1: Based on the orogenic gold mineralization theory and regional geochemical anomalies, the known tectonic altered rock type gold deposits and the surrounding geochemical anomalies are analyzed, and the areas with good element matching and obvious concentration centers are selected as the first preferred target areas;

[0007] Step 2: Carry out 1:2 / 50,000 geochemical survey work for the first preferred target area, and select areas with abnormal development of Au, Cu, Ni, Co, Cr, Sb, and As, good element matching, and obvious concentration centers as the second preferred target area;

[0008] Step 3: Carry out 1:10,000 soil profile measurement for the second preferred target area, and conduct 1:10,000 geological survey in areas with good element matching and obvious concentration centers to identify structural fracture zones with obvious hydrothermal alteration characteristics such as silicification, sericitization, kaolinization, and limonite, and determine them as the third preferred target area;

[0009] Step 4: For the third preferred target area, UAVs are used to identify the linear structure development area and the gold-bearing structural alteration zone is quickly located by stripping soil and taking reconnaissance samples, which is determined as the fourth preferred target area;

[0010] Step 5: For the high-value points or high-value sections of the reconnaissance samples in the fourth preferred target area and the belt-shaped soil geochemical anomaly belts distributed along the structural belt, shallow ore body control is carried out by trenching and shallow drilling to delineate the shallow ore body on the surface;

[0011] Step six, for shallow surface ore bodies, use structural superposition halo technology combined with ore body grade, ore body thickness and ore body grade-thickness product contour map to predict target positions and conduct deep verification of drilling projects to determine the grade, thickness and occurrence changes of deep ore bodies, delineate ore bodies, and estimate gold resource reserves.

[0012] Preferably, the 1:2 / 50,000 geochemical measurement in step 2 is a 1:2 / 50,000 measurement of stream sediment anomalies, and the working analysis elements are mainly Au, Cu, Ni, Co, Cr, Sb, and As; the basic density is measured at 16-32 points / km2, and the sample collection adopts a -10 to +60 interception grade, and the weight of the sieved samples is greater than 300g, half of which is sent for inspection and half is retained; the test data is used to produce geochemical maps using the software GeoExpl, and single element anomaly maps and combined anomaly maps are produced using the software Mapgis6.7, and comprehensive anomaly maps and anomaly analysis maps are produced in combination with the geological background and structural distribution characteristics.

[0013] Preferably, the regional geochemical anomaly in step 1 is a 1:50,000 stream sediment measurement anomaly, and the abnormal characteristic elements include Au, Cu, V, Ni, Sb, and As;

[0014] In the step 2, the 1:2 / 50,000 geochemical measurement selects the abnormal distribution areas of Au, Cu, Ni, Co, Cr, Sb, and As;

[0015] In the step 3, the 1 / 10,000 soil profile measurement selects the location where the Au, As, Sb, Cu, Pb, and Zn elements fit well.

[0016] Preferably, the soil profile measurement scale in step three is 1:10000 or 1:5000; when measuring the soil profile, high-precision handheld GPS positioning is used, samples are collected at a horizontal point spacing of 40m / 10m, and the grain size is cut off at -10 to +60. The sampling medium mainly collects fine rock fragments, fine sand, and silt sand in layer C, and the sample coverage thickness is greater than 0.8m. The residual slope deposits in the lower part of layer B are collected, and the sample collection layers are required to be consistent; the weight of the sample after sieving is not less than 200g, and the test data is used to produce a geochemical comprehensive profile map and anomaly analysis map using software; combined with the structural distribution characteristics, the high-value section of the geochemical profile or the geochemical anomaly zone with a strip distribution is delineated; the soil profile measurement shows that the Au, As, and Sb sub-anomaly intensity is high, the middle and inner zones are well developed, the fit is good, and the concentration center is obvious. The section is the most favorable section for prospecting.

[0017] Preferably, the method of stripping soil and taking reconnaissance samples in step 4 is specifically as follows: the stripping is carried out in the linear negative terrain identified by the drone, the area with thin Quaternary cover and no vegetation; the stripping depth is 30-50 cm and the width is 30-60 cm, so as to clearly observe the mineralized alteration zone and take samples in the zone;

[0018] The samples are collected by continuous picking method, with sample length of 1-2 meters and sample weight greater than 500g. Only gold element is tested in the samples. The stripping interval along the mineralized alteration zone is 40-80 meters. The gold-bearing structural alteration zone can be quickly identified based on the test results.

[0019] Preferably, the operation process of using trenching to expose, trace and control the specific position, shape and characteristics of the mineralized zone or mineralized body in the shallow part in the step 5 is to use the preliminary determination of the position of the surface mineral-bearing geological body and the mineralized layer, and to carry out the specific layout of the trenching project on the basis of field investigation and inspection, and arrange it in the high-value section of the reconnaissance sample with no vegetation coverage, easy construction and coverage thickness not exceeding 3m, and arrange it perpendicular to the direction of the structural alteration zone and the direction of the rock formation; the width of the trench bottom is not less than 0.8m, the depth is not more than 3m, and it penetrates into the bedrock by more than 0.3m, so that the top and bottom plates of the mineralized body or the distribution can be clearly observed. The purpose is to measure the layer interface and the occurrence elements; the chemical sample slot is arranged at the junction of the slot wall and the slot bottom, and the sample number is marked. The continuous groove method is used for sampling. The sample slot specification is 10×5cm. The error rate between the theoretical weight and the actual weight of the sample shall not be greater than 10%. When sampling, the rock surface of the sampling point is cleaned and the sampling cloth is laid to ensure that the sample is not contaminated and splashed. The collection method is strictly carried out according to the specifications, and the samples are laid in the same direction and the same inclination angle; the section where the chemical sample is not collected is controlled by rock samples; the trench exploration project achieves the geological purpose, and after passing the acceptance, it is backfilled in reverse order to restore the topography;

[0020] Through trench exploration, the mineralized alteration zones and mineralized bodies are exposed and controlled, the morphology, occurrence and scale of the mineralized bodies are preliminarily determined, and the surface mineralized bodies are delineated.

[0021] Preferably, in step six, drilling engineering technology is used to determine the changes in the grade, thickness and occurrence of the deep ore body, and the specific operation process of delineating the ore body is: using the delineated shallow surface ore body, drilling deployment is carried out, and the specific drilling is positioned in the surface mineralization-rich area, and the specific positioning is carried out with reference to the occurrence and topography of the rock mass or stratum; the ore body has an inclination angle of 60°, and the drilling engineering construction is a 65°-85° inclined hole. The construction method adopts large-diameter directional drilling, and the outer diameter of the final hole drill bit is not less than 75mm; the average sampling rate of ore cores and rock cores within 5m of the ore body and its top and bottom plates is not less than 85%, and the average sampling rate of the surrounding rock cores by layer is not less than 80%; the drilling sampling method 1 / 2 core splitting is carried out along the long axis direction of the rock core and the uniformity of mineralization. Half of it is sent to the testing unit as the basic analysis sample for processing and testing, and the other half is retained for verification and research; sampling on the mineralized body does not cross layers, the basic sample length is 1.0m, the maximum sample length does not exceed 1.5m, and the minimum must not be less than 0.4m; 1-2 circle samples are taken from the upper and lower plates of the mineralized body, and rock samples are used for control in areas where chemical samples are not collected; the deep grade, scale, and occurrence changes of the mineralized body are determined through drilling projects; the drilling project achieves the geological purpose. After acceptance, the roads, machines, and pools are backfilled in reverse order to restore the topography, and environmentally friendly mud materials are selected in the drilling construction.

[0022] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following excellent effects:

[0023] The present invention has a simple workflow, direct and effective working methods, short working cycle, and a medium-sized gold deposit was submitted in a short period of time. Guided by the theory of East Kunlun orogenic gold mineralization system, prospecting is carried out, and sections with good reproducibility of 1 / 50,000 and 1 / 25,000 geochemical exploration and soil measurement anomalies, high Au, As, Sb sub-anomaly intensity, developed middle and inner zones, good fit, and obvious concentration centers are selected; the location of the gold-bearing structural alteration zone is quickly located by 1 / 10,000 geological grass survey, unmanned aerial vehicle identification of linear negative terrain, and soil stripping to take reconnaissance samples; further use trenching engineering and shallow drilling to control shallow gold ore (mineralization) bodies, and then use the structural superposition halo method combined with the ore body grade, thickness and grade thickness product contour map to predict the target position and conduct deep verification of the drilling engineering to find out the morphology, occurrence, scale and resource potential of the gold mineralization body; finally, restore the topography and landform to minimize environmental disturbance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 This is a flow chart of a method for prospecting for structurally altered rock-type gold deposits in shallow overburden areas according to Example 1 of the present invention;

[0026] Figure 2 1 / 50,000 of the Mangya River and Donghe River areas in Example 1 of the present invention (V, Ni, Au, Co, As) comprehensive anomaly analysis diagram;

[0027] Figure 3 1 / 25,000 GA in the Mangya River and Donghe River areas in Example 1 of the present invention 11 甲 Au (Cu, Ni, As, Mo, Co, Cr, Ag, Pb, Zn, Sb) comprehensive anomaly analysis diagram;

[0028] Figure 4 The 1 / 10,000 soil measurement AP in the Mangya River and Donghe River areas in Example 1 of the present invention 3 甲 Au (As, Sb, Cu, Pb, Zn, Ag) comprehensive anomaly analysis diagram;

[0029] Figure 5 A 1 / 10,000 geological rough survey map of the Mangyahedong area in Example 1 of the present invention;

[0030] Figure 6 The drone takes landscape pictures of the Mangyahedong area in Example 1 of the present invention and interprets the direction of the gold-bearing structural alteration zone;

[0031] Figure 7 The linear negative terrain recognition and reconnaissance sample collection of drones between the 64-80 exploration lines in the Ⅰ and Ⅱ gold-bearing structural alteration zones in the Mangyahedong area in Example 1 of the present invention

[0032] Figure 8 The photos of the chemical samples of the trench exploration project and the trenching of the gold-bearing structural alteration zone No. 1 in the Mangyahedong area in Example 1 of the present invention are as follows;

[0033] Fig. 9 This is a sketch of the 20MTC09 trench exploration project of the No. 1 gold-bearing structural alteration zone in the Mangyahe East area in Example 1 of the present invention;

[0034] Fig.10 This is a cross-sectional view of exploration line 64 of the No. Ⅰ and No. Ⅱ gold-bearing structural alteration zones in the Mangyahe East area in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] refer to Figure 1-10 Taking the Mangya River east area of ​​Qimantag in the western section of East Kunlun as an example, the prospecting effect of the present invention is explained.

[0038] 1. The East Kunlun orogenic belt where the Mangyahedong gold mining area is located is an important mineralization belt in my country. The gold deposits in this belt are mainly produced in the eastern section of the East Kunlun Mountains, while no gold mines with prospecting prospects have been found in the Qimantag area in the western section of the East Kunlun Mountains. This work uses the orogenic gold mineralization theory and selects the 1 / 50,000 water system sediment survey area delineated by previous researchers in the Mangyahedong area of ​​Qimantag in the western section of the East Kunlun Mountains. (V, Ni, Au, Co, As) Comprehensive Abnormality ( Figure 2 ) as the key area for abnormal inspection.

[0039] The term orogenic gold deposit was proposed by Groves et al. (1998) to emphasize the unique spatiotemporal relationship between vein-type mineralization systems in regional metamorphic terranes and orogeny. Initially, orogenic gold deposits only referred to synorogenic mountain-type gold deposits in the middle crust, compression or trans-compression environments, and later gradually expanded to include post-orogenic environments and continuous crustal mineralization models. Summarizing the results of previous research, the main characteristics of orogenic gold deposits are as follows (Wang Jingbin et al., Classification, Mineralization Model and Prospecting of Orogenic Gold Deposits, 2024): ① Post-genetic hydrothermal vein-type gold deposits controlled by structures in metamorphic terranes; ② Close spatiotemporal relationship with orogeny, developed in compression or trans-compression environments at the margins of convergent plates, mineralized in the late stages of orogeny, and gold precipitation and tectonic deformation occurred simultaneously; ③ Continuous crustal mineralization, with mineralization depths ranging from 15 to 20 km to near-surface environment, and is divided into epizonal (<6 km), mesozonal (6-12 km) and hypozonal (>12 km) according to the depth of mineralization. Mineralization can be found in metamorphic rocks from granulite facies to greenschist facies, but most of them are produced in greenschist facies environments; ④ The ore is composed of low-sulfide mainly composed of pyrite-arsenopyrite, and the mineralizing fluid is low-salinity H2O-CO2-CH4 fluid.

[0040] (V, Ni, Au, Co, As) Comprehensive anomaly is located in the north-central area of ​​Mangyahedong. The main element is Cu, and the characteristic combination elements are V, Ni, Au, Co, and As. The anomaly is irregular in shape, with the long axis spreading direction near NWW. The anomaly area is 24.8 km 2 The Au and As element anomalies are well matched, and the Cu, V, Co, and Ni element anomalies are closely related. The northwest section of the anomaly is a large area of ​​Upper Pleistocene flood alluvial layer. The terrain is flat and no geochemical samples have been collected, so the northwest section of the anomaly is not closed. The Qimantag Group clastic rock group (OQ1) and volcanic rock group (OQ2) are exposed in the anomaly area. They are a set of clastic rocks, volcanic rocks and carbonate rocks dominated by shallow metamorphism. The direction of the long axis of the anomaly is consistent with the stratum trend, showing the characteristics of being controlled by the stratum.

[0041] 2. 1 / 25,000 Geochemical Measurement

[0042] The field work method for measuring sediment in 1.1 / 2.5 million water systems is as follows:

[0043] (1) Sample point arrangement

[0044] Sampling points are arranged according to the characteristics of the working area and the geochemical conditions of the landscape in the area. The sampling points for river sediments are arranged using a 1 / 50,000 topographic map magnified to 1 / 25,000; the sampling density is controlled at 16-32 points / square kilometer, and no samples are arranged within the main river system and Quaternary alluvial and diluvial areas; the sampling density is relatively increased in river development areas, mineralization prospective areas, and remote sensing anomaly areas; the sampling density can be appropriately sparsed in sections with difficult passage, generally not less than 16 points / square kilometer; sampling points are mainly arranged at the end of river systems with a length greater than 200 meters and at the mouths of branch river systems, and additional points are arranged for tracing back to the source of river systems with a length greater than 300 meters; for areas where small primary river systems are feather-shaped, points are arranged in the middle of multiple river systems, and multiple river systems are sampled in combination. In intermittent water flow, dry ditches or dry rivers with little water flow, sampling is selected at the bottom of the riverbed, mainly for medium-coarse grained materials in the water system sediments; sampling points should be evenly distributed, with 0.25 square kilometers as the basic sampling unit on the 1 / 25,000 topographic map. Each basic sampling unit is divided into 4 small grids (each small grid is 0.0625 square kilometers). The number of samples in each small grid is required to not exceed 2, and there should be sample points distributed in each small grid as much as possible, and there should be no 5 consecutive blank small grids.

[0045] (2) Sample point number

[0046] The sampling grid (0.25 square kilometers) is divided into large grids with 500-meter lines of the kilometer grid. The large grids are numbered from left to right and from top to bottom. Each basic sampling unit is divided into 4 small grids (each small grid is 0.0625 square kilometers). The numbering sequence is a, b, c, d from left to right and from top to bottom. The samples collected in the small grids are annotated with Arabic numerals in order from top to bottom, such as a1, a2, b1, c1, etc. For example, 5c1 is the sample No. 1 in the c small grid of the 5th large grid.

[0047] (3) Sampling particle size determination

[0048] The work area is located in the western section of the East Kunlun Mountains. The geochemistry belongs to the arid and semi-arid alpine mountain landscape. According to the Geochemical Survey Specification (1:50000) (2015), the sampling particle size is -10 to +60 mesh. And the "Qinghai Province 1:25,000 Geochemical Measurement Specification" (DB 63 / T 1936-2021)" believes that the sampling particle size of the geochemical exploration scanning area in the alpine mountain landscape of Qinghai Province is suitable for -10 to +60 mesh. Combined with the previous 1:50,000 water system sediment measurement in this area, the sampling particle size is -10 to +60 mesh, and a series of comprehensive anomalies such as Au, Cu, V, Co, and Ni have been identified, with remarkable results. In summary, the geochemical measurement work uses the -10 to +60 mesh interception particle size, which can effectively avoid the interference of aeolian sand and achieve the purpose of strengthening anomalies. It is feasible and can better reflect the geochemical distribution characteristics of elements in this work area.

[0049] (4) Repeat sample layout

[0050] Under the premise of considering the uniform distribution and different geological structural units in the map, the repeated sampling grid and a repeated sampling point are randomly determined in advance. The number of repeated sampling is 1% of the total number of samples, and each survey area should be greater than or equal to 30 pieces.

[0051] (5) Field location and sampling

[0052] Every day, the sampling points scheduled for the next working day are compiled into routes, and the coordinates of each sampling point on the route are measured from the 1:2.5000 topographic map, entered into the GPS, and the 20m range alarm setting of the point is enabled to quickly find the sampling point.

[0053] When working in the field, use a 1:2.5000 topographic map for navigation and GPS positioning to find the water system and its specific location of the sampling point on the sampling point layout map. Near the preset point (within 25m above and below the specific sampling point), try to find the part where the coarse and heavy particles of the water system sediment are easy to be retained as the actual sampling point. The original sample weight is determined by the particle size of the sample, but it is not less than 500g. The samples are packaged in cleaned sample bags and covered with plastic bags to prevent mutual contamination of samples. After sampling, the sample number is marked with paint at the actual sampling point.

[0054] The use of handheld GPS in field sampling not only greatly improves the speed and accuracy of fixed-point sampling, but also ensures the sampling rate through GPS track monitoring. The specific approach is: before starting work, the integrity and consistency of the GPS of each work group are checked; the relevant parameters of GPS are set uniformly; each work group turns on the GPS before the first sampling point of the day's work, and during the sample collection process, the sampling point number, coordinates and track are stored for each sampling point until the last sampling point is completed on the day and the GPS is turned off; after work, the GPS is handed over to the track management personnel in a timely manner, and the waypoints and tracks of the day are saved and checked, and archived as original data.

[0055] (6) Field cataloging

[0056] The contents of field sampling records include: the map sheet where the sampling point is located, grid number, bag number, sampling point location and coordinates, sample properties and surrounding geology, mineralization, sampling date and person in charge.

[0057] The 1:25,000 topographic hand map used in the field, after the daily field work, the sampling points are inked, the sampling points are marked with small circles with a diameter of 2mm, and the grid points are numbered. After a certain period of work, all the contents of the hand map are transferred to another topographic map of the same scale to make a base map of the sampling points, and the transfer error is less than 0.5mm.

[0058] (7) Preliminary sample processing and management

[0059] The processing of field samples includes: drying, crushing, screening, mixing, weighing, packing into paper bags, packing and other processes.

[0060] The sample processing group strictly supervises the samples handed over by the sampling group, checks whether the sample weight and medium meet the requirements, and orders them to be reworked if contamination, mixed samples, or wrong numbers are found. For the signed samples, they are dried in time and rubbed from time to time to prevent the sample particles from sticking together. The dried samples are gently tapped with a wooden hammer to disintegrate the particles in the clay cement, so as to prepare for effective screening. The particle size range of the sieved samples is -10 mesh to +60 mesh, and the weight of the analytical sample and the sub-sample is not less than 150g. Standard stainless steel sieves are used for sample screening. Before processing each sample, the sieving tools are carefully checked and cleaned to prevent contamination or mixing of non-intercepted particle materials. The amount of non-intercepted particle particles mixed does not exceed 5% of the mass of the processed sample. Before screening, mixing and bagging, the samples are checked against the original handover form and the cloth bag number and the number on the sample paper bag to avoid the wrong number of the sample. The samples are packed in a timely and orderly manner according to the sample delivery batch and the sample delivery form, and the sample quantity and start and end numbers are marked on the outside of the box. The individual sample bags are tightly sealed, and water-proof and moisture-proof plastic sheets are used as padding when packing. The samples are separated by layers or packages, and the top of the box is filled with cardboard before being covered. The sample box is free of moisture and damage during storage and transportation.

[0061] 2. Abnormalities in 1:25,000 water system sediment measurements

[0062] The 1:25,000 stream sediment survey identified 39 comprehensive anomalies in this area and its surrounding areas based on the identification of single element anomalies. According to the anomaly classification principles of the "Qinghai Province 1:25,000 Geochemical Survey Specification" (DB 63 / T1936-2021), there are 4 Class A anomalies, 29 Class B anomalies, and 6 Class C anomalies.

[0063] Main abnormal GA 11 甲 Au (Cu, Ni, As, Mo, Co, Cr, Ag, Pb, Zn, Sb) is the largest and most intense gold anomaly in the Mangyahe East area ( Figure 3 The abnormal area is located in the northeast and west of Mangya River, and is irregularly distributed in the northwest-southeast direction. The area is about 6.94km 2 . The access road is very convenient.

[0064] The abnormal area is located in the northeast and west of Mangya River, and is irregularly distributed in the northwest-southeast direction. The area is about 6.94km 2 . The access road is very convenient.

[0065] The main exposed strata in the abnormal area are the Ordovician Qimantag Group volcanic rock group, clastic rock group and a small amount of Quaternary. The main rocks of the Ordovician Qimantag Group volcanic rock group are altered andesitic basalt; the main lithology of the clastic rock group is siliceous clay slate, siliceous rock and crystal; the Quaternary is a late Pleistocene flood alluvial area; intrusive rocks are not developed in the area; there are many reverse faults in the abnormal area that are parallel to the northwest and southeast.

[0066] The main element of the anomaly is Au, and the characteristic combination elements are Cu, Ni, As, Mo, Co, Cr, Ag, Pb, Zn, and Sb. The Au anomaly is composed of six sub-anomalies, Au12, Au13, Au16, Au17, Au20, and Au22. Among them, Au13, Au16, and Au22 sub-anomalies have three-level concentration zones and are large in scale. The Au13 sub-anomaly has 8 anomaly points and an anomaly area of ​​0.39 km 2 , the average element value is 332.73×10 -9 , with a peak value of 1710.0×10 -9 ; Au16 sub-anomaly, with 11 anomaly points and an anomaly area of ​​0.41km 2 , the average element value is 8.91×10 -9 , with a peak value of 15.8×10 -9 ; Au22 sub-anomaly, with 38 anomaly points and an anomaly area of ​​1.80km 2 , the average element value is 9.24×10-9 , with a peak value of 38.1×10 -9 The Au, Cu, Ni, Cr, Co and As elements are relatively well matched, with obvious concentration zones and large anomaly scale.

[0067] 3. 1 / 10,000 Soil Measurement

[0068] This working method is carried out for 1 / 25,000 geochemical measurement anomalies and is only deployed in 1 / 25,000 comprehensive anomaly GA 11 甲 The purpose is to further narrow the target area, delineate the gold polymetallic element abnormal area, and provide a basis for subsequent work.

[0069] 1. Working methods

[0070] Soil measurement uses GPS positioning combined with semi-instrumental method (compass) to locate the starting point of the sampling line. The sampling grid is 100 meters (line distance) and 40 meters (point distance), and the sampling line is 40°. The sampling is based on the enlarged 1 / 10,000 topographic map as a hand map, and the soil measurement network is laid out. Each sampling group samples according to the measurement network laid out on the hand map and their own sampling lines. The sampling interval is 40 meters (horizontal distance). The samples are mainly collected within 5 meters around the sampling point using the multi-pit (point) sampling method. When there is bedrock outcropping, waste rock pile, riverbed accumulation, and steep slopes that cannot be sampled, the points are abandoned and noted in the records. The samples are mostly based on the C layer (parent material layer) and residual layer. The sampling depth is 10-40 cm in the ridge and the area with good bedrock outcropping, and the sampling depth is generally 50-100 cm in the area with thick Quaternary coverage. The sample composition is mainly medium-coarse sand and rock debris. The original weight of the samples is greater than 500 grams. The sample size is -10-+60 mesh, and the sample is processed with a stainless steel sieve. The weight of the sample after rough processing is guaranteed to be 200 grams. The processed samples are sealed with plastic bags to prevent contamination between samples. Every 5 samples are marked clearly for inspection.

[0071] The sampling record uses the soil measurement sampling record form, and the record content includes line number, point number, sample bag number, sampling location, sampling depth, layer, sample composition and geological and geomorphological features near the sampling point, sampling date and sampler, etc.

[0072] 2. Field sample initial processing and management

[0073] After the field sampling personnel complete the daily sampling, they will promptly sort out and fill out the sample delivery form and send the samples to the processing personnel for acceptance and registration. The processing personnel will promptly correct or re-collect the wrong number, missed sampling, and samples that do not meet the requirements. To prevent contamination of the collected samples, all the cloth bags containing the samples are washed before use. The samples in the cloth bags are naturally dried as required, and the samples are rubbed from time to time during the drying process to effectively avoid soil caking. After the samples are dried, they are sieved with a -10-+60 stainless steel sieve. The sieved samples are mixed by diagonal folding method, and then put into paper bags for weighing. The sampling particle size is -10-+60 mesh, and the final weight of the samples is greater than 150 grams. To prevent contamination when processing samples in the field, after each sample is processed, all utensils that have been in contact with the previous sample are cleaned with a brush before processing the next sample. Each sample packed in a paper bag is marked with detailed information such as the work area, sample number, date, etc. After filling out the sample delivery form and compiling the sample processing number sheet, the samples are properly kept. Quality inspection is carried out immediately after processing every day to ensure that the samples are processed accurately.

[0074] 3. Data processing and map preparation

[0075] (1) Data processing and anomaly identification

[0076] First, the detection limit, reporting rate, accuracy and precision of the analysis of the sample elements in the measurement area provided by the laboratory, as well as the sampling of duplicate samples and abnormal passwords were comprehensively tested to determine the reliability of the analysis data. Under this premise, the analysis data of each element was processed by computer. The calculation method adopts the "global data outlier point iteration method". That is, values ​​greater than X+3S and values ​​less than X-3S (X represents the average value; S represents the deviation) are gradually eliminated until there are no high points or low points to be eliminated, and the average value (X) and standard deviation (S) are calculated, and then the average value plus 2 times the standard deviation value (X+2S) is approximated as the lower limit of abnormality (T). The concentration zoning value is determined according to the standard Tz=2K×T, K=0, 1, 2. According to the geochemical characteristics and geological mineralization conditions in the survey area, the main mineralization elements and associated elements are selected, and the calculated lower limit of anomaly is used as the standard. On the basis of combining the geochemical map, the lower limit of anomaly use of the analyzed elements in the survey area is determined, and the abnormal concentration zone is outlined with the concentration zoning value, which is the single element anomaly. After that, for the element anomalies with good fit and close correlation, the corresponding abnormal characteristic parameters are statistically analyzed, and the abnormal points, peak height, average intensity, contrast, scale, concentration characteristics, etc. of each element are used as indicators to evaluate the abnormal elements, determine their main elements and associated elements, and finally delineate the comprehensive anomaly in combination with the geological mineralization background of the abnormal fit area.

[0077] (2) Drawing preparation

[0078] a. Preparation of original data map and single element anomaly map: Draw the measurement area and point lines according to the measured position and the measured point-line distance, and mark the original data of the analysis on the corresponding points according to the analyzed test elements, so as to make the original data map. On the single element original data map, use the calculated lower limit of each element anomaly and the corresponding concentration zone value to circle the anomaly boundary line and its internal concentration zone boundary line. After review, adjust the inappropriate lower limit of anomaly, and then smooth the mechanical lines. Color each element according to its specified color within the fixed range, which is the single element anomaly map.

[0079] b. Anomaly analysis diagram: With the same scale as the geochemical map, arrange all the single element anomalies and the corresponding geological mineral map in blocks. The single element names and their anomaly zoning legends are marked in their respective blocks, and the outer, middle and inner zones of the single elements in the block are filled from light to dark according to the common colors of each element to indicate the concentration zoning. For those with multiple concentration centers, they are numbered from top to bottom and from left to right. The scale centimeter grid is divided on the block single line frame, and the centimeter grid data is marked on one of the block maps. AP is used as the identifier of soil anomalies.

[0080] AP3 Soil Anomaly ( Figure 4 )

[0081] The anomaly is located in the northeastern corner of Mangya River, with an irregular NW-SE distribution. The main element is Au, and the combined elements are As, Sb, Cu, Pb, Zn, and Ag. The outcropping strata in the anomaly area are the Ordovician Qimantag Group volcanic rock group (OQ2). The Au, As, Sb, Cu, Pb, and Zn elements are well matched, and the zoning of each element is obvious. The Au anomaly area is 0.36 km 2 , with a peak value of up to 1890×10 -9 . Au is well matched with AS and Sb. In the later stage of anomaly inspection, the newly discovered gold-bearing structural alteration zones Ⅰ, Ⅱ and Ⅳ are located within the anomaly through soil stripping detection sampling and 33 trench exploration projects. Among the three gold zones within the anomaly range, 8 gold ore bodies (Ⅰ-1, Ⅰ-2, Ⅰ-3, Ⅱ-1, Ⅱ-2, Ⅳ-1, Ⅳ-2, Ⅳ-3) and 1 Ⅱ-3 zinc ore body have been delineated. The anomaly is a mineral-induced anomaly. Its ore-bearing lithology is tectonic breccia, tectonic foliated altered andesitic basalt and mylonite. The ore-bearing surrounding rock is altered andesitic basalt. The ore body belongs to the tectonic alteration rock type. At present, the control degree of the three gold-bearing structural alteration zones and the ore bodies in the zones is generally not high. Therefore, the anomaly has good gold prospecting potential. This anomaly is consistent with the 1:25,000 geochemical survey GA 11 甲 The middle part of the Au (Cu, Ni, As, Mo, Co, Cr, Ag, Pb, Zn, Sb) comprehensive anomaly corresponds well to the sub-anomalies such as Au, As, Pb, and Zn.

[0082] 4. 1 / 1 Geological Survey

[0083] The rough survey work is arranged at 1:25,000 GA 11 甲 Au (Cu, Ni, As, Mo, Co, Cr, Ag, Pb, Zn, Sb) and AP3 soil anomalies, a 1:2000 geological profile was selected in the grass survey area through field survey, where the bedrock is continuously exposed, the structure is clear, and the rock types are relatively complete. The profile is basically perpendicular to the structural line direction and stratum trend in the area. The profile survey uses a portable GPS to locate the starting and ending coordinates, a compass to measure the guide wire direction, slope angle, and rock formation occurrence, a tape measure to measure the distance and draw the topographic line, calibrate the sampling points and redraw the geological content. A 1:50,000 topographic map was used as a working hand map after being digitally processed and enlarged to form a 1:10,000 topographic map. The starting position of the route, the calibrated geological points, and the navigation direction were determined by interpreting the topographic map and referring to the data of a portable GPS locator. The work was carried out by taking the method of crossing as the main method and tracing as the auxiliary method, with the purpose of sorting out the fault structure, defining the geological boundary, and finding and discovering the gold-bearing structural fractured alteration zone and the copper-lead-zinc mineralized geological body. A total of 35 routes were formed, with a single route length of 2.0-5.5km, and a total of 22.0km was completed. 2 (including 13.5km of bedrock area 2 , Quaternary area 8.5km 2 ) A total of 911 geological observation points were calibrated (48 in the Quaternary system and 863 in the bedrock area), with an average of 63.9 effective geological observation points per square kilometer. The route spacing is 200m; the point spacing varies from 20 to 200m. Generally, the point spacing between control points in a single lithology section is larger (150-200m). The structural control points or lithology boundary points are based on the division of geological structures and lithology boundaries, and the point spacing is generally 20-100m. Various geological bodies and structural lines were systematically controlled, divided and circled, and finally a geological sketch was formed ( Figure 5 b).

[0084] Through this work, the strata, structures, and magmatic rocks within the scope of the preliminary survey were divided and defined in detail. The basic pattern of strata, structures, and magmatic rocks in the mapping area was truly and objectively reflected, and relatively systematic and complete first-hand field data were obtained. Multiple structural alteration zones, 5 gold-bearing structural alteration zones, and 1 lead-zinc mineralization zone were newly discovered, providing a direct basis for subsequent work. The scope of this work was properly arranged and the results were remarkable.

[0085] 5. UAV Identification of Linear Negative Terrain

[0086] Using a certain brand of drone, set the camera parameters as follows: resolution 1080P 60fps, ISO 800-1600, shutter speed 1 / 30 second, aperture automatic aperture, white balance automatic white balance. Choose a windless and clear day to take photos, and fly at an altitude of 50-100 meters.

[0087] Export the photos taken by the drone and use the photo processing tools on the computer to identify the obvious linear traces such as straight lines or arcs as the objects. Select large-scale, long-extending, negative terrain, with a certain width (more than 1 meter), and developed fault scarps, fault triangles, or mountain faults along the fault lines, marked with red lines as the basis for tracing and collecting reconnaissance samples ( Figure 6 , Figure 7 ).

[0088] 6. The stripping is selected in the linear negative terrain (the part where the structure passes through) identified by the drone, the thin Quaternary cover, and the area without vegetation. The stripping depth is generally 30-50 cm and the width is 30-60 cm. The purpose is to clearly observe the mineralized alteration zone and take samples in the zone. The sample collection uses the continuous picking method. The sample length is 1-2 meters and the sample weight is greater than 500g. Only gold elements are tested for inspection. The stripping spacing of the mineralized alteration zone is preferably 40-80 meters. According to the test results (greater than 0.2g / t), the gold-bearing structural alteration zone can be quickly identified to provide a basis for the establishment of subsequent prospecting signs and the deployment of trench exploration projects.

[0089] 7. Trenching Engineering

[0090] Trench exploration projects mainly reveal geophysical and geochemical anomalies through the identification of linear negative terrain by drones, geological surveys, and a large number of soil stripping reconnaissance samples ( Figure 7 ) and the direction of newly discovered mineralization bodies. From the perspective of construction results, all trenching projects have achieved geological objectives. From the perspective of the results achieved, various mineralization clues have been revealed through trenching projects, and many gold, tungsten, cobalt (nickel), lead and zinc polymetallic mineralization bodies have been identified in the area, achieving good results and significant effects ( Figure 8 , 9 ).

[0091] The average bottom width of the trenching project is between 0.67-2.14m; the average opening width is between 1.04-2.84m, the average trench depth is between 0.54-3.00m, and the trench is dug into the bedrock for more than 0.30m; stakes are set up at the trench head and the project number is indicated. The trenching project has achieved the geological purpose, the quality acceptance is qualified, and the workload is confirmed to be valid ( Figure 8 a).

[0092] Sampling quality: Basic chemical analysis samples are collected from the areas with strong mineralization and alteration in the trench exploration project, and the samples are collected at the intersection of the trench wall and the trench bottom. The sampling method is continuous groove method, the general sample length is 1.00m, the shortest is 0.40m (quartz vein), the longest is 1.50m, and the cross-section specification of the sample groove is 10×5cm (gold ore body) ( Figure 8 b) 10×3cm (lead-zinc polymetallics), the top and bottom plates of the mineral (mineralized) body are controlled by 1-2 sample ring edges. A total of 1,817 chemical samples were collected in this trench exploration project, and 668 groove sampling quality inspections were carried out, with an inspection rate of 36.76%. The sample distribution and sampling were reasonable, without mixed samples, flying samples, and cross-layer sampling. The difference between the actual weight and the theoretical weight of the collected chemical samples, that is, the maximum deviation rate, was 9.92%, which met the standard requirement of within 10% of the allowable error range of weight (the theoretical weight of a sample with a length of 1.00m is 12.5kg). The areas where chemical samples were not collected were controlled by engraved rock samples, and the samples were separated by red paint lines, and the sample numbers were marked at the corresponding positions. There was no cross-layer sampling. The sample distribution was reasonable and standardized.

[0093] Cataloging quality: The cataloging of trench exploration projects is carried out on site. Generally, the left wall and bottom are cataloged according to the project orientation. If the left wall is missing, the right wall and bottom are cataloged, and a wall-bottom expansion diagram is drawn. The cataloged information is complete, true, timely and neat.

[0094] 8. Drilling Engineering

[0095] According to the design plan: the drilling project spacing is 80-320 meters, and the controlled oblique depth of the gold ore body is 80-160 meters. The project team has laid out 24 drill holes for the gold mineralization-enriched areas of the Ⅰ, Ⅱ, and Ⅳ zones in the area. Each gold-bearing structural alteration zone extends steadily to the depth, and the mineralization alteration is strong. The gold ore bodies Ⅰ-1, Ⅰ-3, Ⅱ-1, Ⅱ-2, Ⅱ-5 on the surface of the Ⅰ and Ⅱ gold-bearing structural alteration zones have stable extensions in the depth. The results of this work are quite significant ( Fig.10 ).

[0096] According to the eight indicators of "Drilling Quality Acceptance Grade Standard", the quality of each drilling hole is qualified and the quality assessment is all above "good".

[0097] 9. Construction superposition halo method

[0098] The gold ore body extends stably along the inclined direction, and the main ore body with a maximum inclined depth of 340m is not enclosed in the deep part. The structural superposition halo research work carried out in the gold main ore bodies of gold-bearing structural alteration No. Ⅰ and No. Ⅱ was selected. A total of 10 samples were collected from the surface trenching project to the deep drilling project for analysis and testing (Table 1). Compared with the structural superposition halo model of the Wulonggou gold deposit in the whole country and the East Kunlun, the characteristic indicator element combination of the front edge halo in this area was determined: As, Sb, Hg; the characteristic indicator element combination of the near-ore halo: Au, Ag, Cu, Pb, Zn; the characteristic indicator element combination of the tail halo: Co, W, Mo, Ni. Among them, the Ⅰ-4 and Ⅰ-6 ore bodies in the southeast of the No. Ⅰ gold-bearing tectonic alteration zone were studied from an altitude of 3500m to 3100m. The deep near-ore halo showed an inner belt or strong belt anomaly, the front halo showed an outer belt, and the tail halo showed a middle-inner belt, indicating that the ore body (Ⅰ-6) has a great extension to depth; the Ⅰ-3 ore body in the middle of the No. Ⅰ gold-bearing tectonic alteration zone was studied from an altitude of 3350m to 3100m. The deep near-ore halo showed a middle-inner belt anomaly, and the front halo and tail halo coexisted as middle-inner belt anomalies, indicating that there are blind ore bodies in depth; the Ⅱ-3 ore body in the middle of the No. Ⅱ gold-bearing tectonic alteration zone was studied from an altitude of 3410m to 3175m. The deep near-ore halo showed a middle-inner belt anomaly, and the front halo and tail halo coexisted as middle-inner belt anomalies, indicating that there are blind ore bodies in depth.

[0099] Table 1 Comprehensive characteristics of the structural superposition halo of the main gold ore body in the Mangyahedong area

[0100]

[0101]

[0102] In summary, in the 1:50,000 water system sediment measurement anomaly optimization work area, the 1:25,000 geochemical measurement is used to initially narrow the prospecting target area, and the 1:10,000 soil profile measurement and 1:10,000 geological survey are used to further narrow the prospecting target area, and the UAV is used to identify the linear negative terrain development section to lock the favorable location for prospecting, and the gold-bearing structural alteration zone is quickly located by taking scouting samples by stripping, and the trenching project is used for surface control, and the structural superposition halo method is used to combine the ore body grade, ore body thickness and ore body grade thickness product contour map to predict the target position and conduct deep verification of the drilling project, and finally restore the topography to find out the shape, occurrence, scale and resource potential of the gold mineralization body. The prospecting method combination is area geochemical exploration + 1:10,000 geological survey + 1:10,000 soil survey + UAV structure identification + stripping to collect scouting samples + shallow engineering verification + structural superposition halo prediction + deep engineering verification.

[0103] Through this combination of methods, 5 gold-bearing structural alteration zones were finally delineated in the Mangya River East area, and 18 gold ore bodies were delineated within the zones. The 18 gold ore bodies were 70-1210 m long, 0.8-9.34 m true thickness, and 1.01-8.86×10 -6The average grade of the deposit is 2.91×10 -6 , industrial grade ore bodies account for 65.63%. Preliminary estimates show that the inferred resource volume is medium-sized, and further work is expected to reach large scale.

[0104] A major breakthrough in gold prospecting has been achieved in the Mangyahedong area through the exploration method of the present invention, indicating that the combination of the exploration technology method has a good prospecting effect in searching for tectonic alteration rock-type gold deposits related to orogenic movement in Qimantag, East Kunlun. It should be noted here that the exploration method of tectonic alteration rock-type gold deposits in shallow overburden areas of the present invention is not only for the Mangyahedong deposit, but is specifically described by taking the Qimantag area as an example.

[0105] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0106] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for prospecting for structurally altered rock-type gold deposits in shallow overburden areas, characterized in that: The following steps are involved: Step 1: Based on the orogenic gold mineralization theory and regional geochemical anomalies, the known tectonic altered rock type gold deposits and the surrounding geochemical anomalies are analyzed, and the areas with good element matching and obvious concentration centers are selected as the first preferred target areas; Step 2: Carry out 1:25,000 geochemical survey work for the first preferred target area, and select the areas with abnormal development of Au, Cu, Ni, Co, Cr, Sb, and As, good element matching, and obvious concentration centers as the second preferred target area; Step 3: Carry out 1:10,000 soil profile measurement for the second preferred target area, and conduct 1:10,000 geological survey in the area with good element matching and obvious concentration center to identify the structural alteration zone with obvious hydrothermal alteration characteristics of silicification, sericitization, kaolinization and limonite, and determine it as the third preferred target area; Step 4: For the third preferred target area, UAVs are used to identify the linear structure development area and the gold-bearing structural alteration zone is quickly located by stripping soil and taking reconnaissance samples, which is determined as the fourth preferred target area; Step 5: For the high-value points or high-value sections of the reconnaissance samples in the fourth preferred target area and the belt-shaped soil geochemical anomaly belts distributed along the structural belt, shallow ore body control is carried out by trenching and shallow drilling to delineate the shallow ore body on the surface; Step six, for shallow surface ore bodies, use structural superposition halo technology combined with ore body grade, ore body thickness and ore body grade-thickness product contour map to predict target positions and conduct deep verification of drilling projects to determine the grade, thickness and occurrence changes of deep ore bodies, delineate ore bodies, and estimate gold resource reserves.

2. The method for prospecting for structurally altered rock-type gold deposits in shallow overburden areas according to claim 1, characterized in that: The 1:2 / 50,000 geochemical measurement in step 2 is an abnormal measurement of stream sediments at 1:2 / 50,000, and the working analysis elements are mainly Au, Cu, Ni, Co, Cr, Sb, and As; The basic density of the measurement is 16-32 points / square kilometer. The sample collection adopts the cut-off particle size of -10 to +60. The weight of the sieved samples is greater than 300g. Half of them are sent for inspection and half are retained. The test data are used to produce geochemical maps using the software GeoExpl, and single element anomaly maps and combined anomaly maps using the software Mapgis6.

7. Comprehensive anomaly maps and anomaly analysis maps are produced based on the geological background and structural distribution characteristics.

3. The method for prospecting for structurally altered rock type gold deposits in shallow overburden areas according to claim 1, characterized in that: The regional geochemical anomaly in step 1 is a 1:50,000 stream sediment measurement anomaly, and the abnormal characteristic elements include Au, Cu, V, Ni, Sb, and As; In the step 2, the 1:2 / 50,000 geochemical measurement selects the abnormal distribution areas of Au, Cu, Ni, Co, Cr, Sb, and As; In the step 3, the 1 / 10,000 soil profile measurement selects the location where the Au, As, Sb, Cu, Pb, and Zn elements fit well.

4. The method for prospecting for structurally altered rock type gold deposits in shallow overburden areas according to claim 1, characterized in that: The soil profile measurement scale in the step 3 is 1:10000 or 1:5000; when measuring the soil profile, high-precision handheld GPS positioning is used, samples are collected at a horizontal point distance of 40m / 10m, and the grain size is cut off at -10 to +60. The sampling medium mainly collects fine rock fragments, fine sand, and silt sand in the C layer, and the sample covering thickness is greater than 0.8m. The residual slope deposits in the lower part of the B layer are collected, and the sample collection layer is required to be consistent; the weight of the sample after sieving is not less than 200g, and the test data is used to produce a geochemical comprehensive profile map and anomaly analysis map using software; combined with the structural distribution characteristics, the high-value section of the geochemical exploration profile or the geochemical exploration anomaly zone with a strip distribution is delineated; the soil profile measurement shows that the Au, As, and Sb sub-anomaly intensity is high, the middle and inner zones are well developed, the fit is good, and the concentration center is obvious. The section is the most favorable section for prospecting.

5. The method for prospecting for structurally altered rock type gold deposits in shallow overburden areas according to claim 1, characterized in that: The method of stripping soil and taking reconnaissance samples in step 4 is specifically as follows: stripping soil is selected in the linear negative terrain identified by the drone, the area with thin Quaternary cover and no vegetation; the stripping depth is 30-50 cm and the width is 30-60 cm, so as to clearly observe the mineralized alteration zone and take samples in the zone; The samples are collected by continuous picking method, with sample length of 1-2 meters and sample weight greater than 500g. Only gold element is tested in the samples. The stripping interval along the mineralized alteration zone is 40-80 meters. The gold-bearing structural alteration zone can be quickly identified based on the test results.

6. The method for prospecting for structurally altered rock type gold deposits in shallow overburden areas according to claim 1, characterized in that: The operation process of using trenching to expose, trace and control the specific position, shape and characteristics of the mineralized zone or mineralized body in the step 5 is to use the preliminary determination of the position of the surface mineral-bearing geological body and the mineralized layer, and to carry out the specific layout of the trenching project on the basis of field investigation and inspection, and arrange it in the high-value section of the reconnaissance sample with no vegetation coverage, easy construction and a coverage thickness of no more than 3m, and arrange it perpendicular to the direction of the structural alteration zone and the direction of the rock formation; the width of the trench bottom is not less than 0.8m, the depth is not more than 3m, and it penetrates into the bedrock by more than 0.3m, so as to clearly observe the top and bottom plates or stratification interfaces of the mineralized body, and can be based on the measurement of the occurrence elements; The chemical sample slot is arranged at the junction of the slot wall and the slot bottom, and the sample number is marked. The continuous notch method is used for sampling. The sample slot specification is 10×5cm. The error rate between the theoretical weight and the actual weight of the sample shall not be greater than 10%. When sampling, the rock surface of the sampling point is cleaned and the sampling cloth is laid to ensure that the sample is not contaminated and splashed. The collection method is strictly carried out according to the specifications, and the samples are laid in the same direction and at the same inclination. The areas where chemical samples were not collected were controlled by using rock samples; after the trenching project achieved the geological purpose and passed the acceptance, the topography was restored by backfilling in reverse order; Through trench exploration, the mineralized alteration zones and mineralized bodies are exposed and controlled, the morphology, occurrence and scale of the mineralized bodies are preliminarily determined, and the surface mineralized bodies are delineated.

7. The method for prospecting for structurally altered rock type gold deposits in shallow overburden areas according to claim 1, characterized in that: In step 6, the drilling engineering technology is used to determine the changes in the grade, thickness and occurrence of the deep ore body. The specific operation process of delineating the ore body is as follows: using the delineated shallow surface ore body, drilling deployment is carried out, and the specific drilling is positioned in the surface mineralization-rich section, and the specific positioning is carried out with reference to the occurrence and topography of the rock mass or stratum; the ore body has an inclination of 60°, the drilling engineering construction is a 65°-85° inclined hole, the construction method adopts large-diameter directional drilling, and the outer diameter of the final hole drill bit is not less than 75mm; the average collection rate of ore cores and rock cores within 5m of the ore body and its top and bottom plates is not less than 85%, and the average layered collection rate of surrounding rock cores is not less than 80%; The drilling sampling method is to split the core 1 / 2 along the long axis direction of the rock core and the uniformity of mineralization, half of which is sent to the testing unit for processing and testing as the basic analysis sample, and the other half is retained for verification and research; sampling on the mineralized body does not cross layers, the basic sample length is 1.0m, the maximum sample length does not exceed 1.5m, and the minimum must not be less than 0.4m; 1-2 circle samples are taken from the upper and lower plates of the mineralized body, and rock samples are used for control in areas where chemical samples are not collected; the deep grade, scale, and occurrence changes of the mineralized body are determined through drilling projects; the drilling project achieves the geological purpose, and after acceptance, the roads, machines, and pools are backfilled in reverse order to restore the topography, and environmentally friendly mud materials are selected in the drilling construction.

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