Positioning method for deep broken alteration area of granite type uranium deposit

Abstract

The invention belongs to the technical field of uranium resource deep detection, and particularly relates to a granite type uranium deposit deep crushing alteration area positioning method comprising the following steps: determining a work scope according to granite exposure conditions; carrying out water system deposition sampling in the determined working range; analyzing the collected sample, counting the content of the lead element, and delineating the abnormal range of the lead element; carrying out ground magnetic gradient measurement in the determined working range to obtain magnetic gradient data of each point; delineating a magnetic gradient modulus high value area according to the magnetic gradient data of each point; the overlapped part of the lead element abnormal range and the magnetic gradient modulus high-value region is the plane range of the crushing alteration region; according to the determined plane range of the broken alteration area, induced polarization sounding work is carried out; delineating an induced polarization abnormal space region; and positioning the space range of the crushing alteration area. According to the method, the deep broken alteration area of the granite type uranium mine can be rapidly delineated.

Description

Technical Field

[0001] The invention belongs to the technical field of deep detection of uranium resources, and in particular relates to a method for locating a deep fractured alteration zone of a granite-type uranium deposit. Background Art

[0002] With the rapid development of my country's nuclear power industry, the demand for uranium resources will increase in the future. Granite-type uranium deposits are one of the four major types of uranium deposits in my country, and many uranium deposits have been found in the past few decades. Most of the discovered deposits and mineralization sites are closely related to the broken zones in granite, especially in some large-scale fractured structural broken zones and fissure zones, which are more prone to alteration and mineralization.

[0003] Most of the granite uranium deposits that have been discovered are located in shallow areas. Because the landmark phenomena such as fracture zones are easy to find, the fracture and alteration phenomena of deep granite cannot be directly observed on the surface. As a result, the current search for deep granite-type uranium deposits lacks direction, and deep prospecting space is often missed, resulting in potential mineralization areas remaining undiscovered.

[0004] Therefore, establishing a method to delineate the deep fractured and altered zones of granite-type uranium deposits is a key factor in breaking through deep granite-type uranium deposits. Summary of the invention

[0005] The purpose of the present invention is to provide a method for locating the deep fractured alteration zone of a granite-type uranium deposit. The method adopts lead element anomaly range delineation, ground magnetic gradient measurement and induced polarization sounding to locate the deep fractured alteration zone of a granite-type uranium deposit, which can effectively solve the technical problem that the deep fractured alteration zone of a granite-type uranium deposit cannot be located at present.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A method for locating a deep fractured alteration zone in a granite-type uranium deposit, the method comprising:

[0008] Step 1: Determine the scope of work based on the exposure of granite;

[0009] Step 2: Carry out stream sediment sampling within the determined working scope;

[0010] Step 3: Analyze the collected samples, count the lead content, and identify the abnormal range of lead content;

[0011] Step 4: Carry out ground magnetic gradient measurement within the determined working range to obtain magnetic gradient data at each point;

[0012] Step 5: Based on the magnetic gradient data of each point, circle the area with high magnetic gradient modulus value;

[0013] Step 6: The overlapped part of the lead element anomaly range obtained in step 3 and the magnetic gradient modulus high value area obtained in step 5 is the plane range of the fractured alteration zone;

[0014] Step 7: Conduct induced polarization sounding according to the plane range of the fractured alteration zone determined in step 6;

[0015] Step 8: Delineate the abnormal spatial area of ​​induced polarization;

[0016] Step 9: Locate the spatial extent of the fractured alteration zone.

[0017] The step 2 is specifically as follows: the water system sediment sampling working scale is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 500 meters; the sampling material is mainly silt and silt, and the particle size is required to be less than the particle size of the 60 mesh sieve; the sample retention weight is not less than 150 grams.

[0018] The step 3 comprises:

[0019] Step 3.1: Analyze the collected samples using atomic fluorescence spectrometry to obtain the lead content data at each point;

[0020] Step 3.2: Based on the lead content data at each point, calculate the lower limit of lead anomaly delineation according to the following formula:

[0021]

[0022]

[0023] In the formula,

[0024] Pb(i,j) is the lead content data of each point;

[0025] Pb is the average value of lead content at each point;

[0026] i, j is the jth measuring point on the i-th measuring line of the sampling, there are m measuring lines and n measuring points in total;

[0027] σ is the standard deviation of the data;

[0028] A(Pb) is the lower limit of abnormal lead content;

[0029] Step 3.3: Grid the lead content data Pb(i,j) of each point using surfer software to obtain a lead content contour map, and circle the plane area where the lead content value is higher than the abnormal lower limit of the lead content A(Pb), which is recorded as the lead element abnormal range.

[0030] The step 4 is specifically as follows: the working scale of the magnetic gradient measurement is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 100 meters; a GSM-19GW series magnetometer is used, the gradient measurement mode is used, the two magnetic probes are kept horizontal, the probe directions are kept consistent, and the probe rods connecting the two probes are perpendicular to the ground, and the deflection angle does not exceed 10°; the height of the lower probe from the ground is greater than 2 meters, and the distance between the upper probe and the lower probe is 0.5 meters, and the magnetic gradient data of each point is obtained.

[0031] The step 5 comprises:

[0032] Step 5.1: Using the magnetic gradient data of each point obtained in step 4, calculate the absolute intensity of the magnetic gradient at each point according to the following formula:

[0033]

[0034] Where, M(i,j) is the magnetic gradient data of each point; |M|(i,j) is the absolute intensity of magnetic gradient at each point; i and j are the jth measuring point on the i-th measuring line of the sampling of the measuring line; when it is the first or last measuring point, the square average of the point and the adjacent measuring points is taken as the absolute intensity of magnetic gradient at the point;

[0035] Step 5.2: 1.5 times the arithmetic mean of the absolute intensity of magnetic gradients at all measuring points is taken as the anomaly lower limit L;

[0036] Step 5.3: Calculate the ratio r(i,j) of the absolute intensity of the magnetic gradient at each measuring point to the lower limit of the anomaly;

[0037] The ratio data r(i, j) of each measuring point is gridded using surfer software to obtain a contour map. The plane range greater than 1 in the map is circled and recorded as the high-value area of ​​the magnetic gradient modulus.

[0038] The specific steps of step 7 are as follows: the survey line of the induced polarization sounding work needs to cover the plane range of the broken and altered zone determined in step 6, and exceed the demarcated boundary by at least 2 kilometers; the survey line spacing is 500 meters, and the point spacing is 50 meters; a symmetrical quadrupole device is used to obtain the polarization rate values ​​of different depths of underground measuring points by changing the transmission distance at different measuring points along the survey line. The transmission distance does not exceed 2 kilometers, and the detection depth is half of the transmission distance, so as to obtain the polarization rate values ​​of different depths of each measuring point in each profile.

[0039] The step 8 comprises:

[0040] Step 8.1: Use the minimum curvature grid method to grid the depth polarizability values ​​of each measuring point in the profile in step 7 in the drawing software to obtain the polarizability contour map of each profile, and circle the area with a polarizability higher than 4% as the high polarizability range;

[0041] Step 8.2: Connect the high polarizability ranges circled on each section along the shortest path to obtain the spatial distribution range of the high polarizability region, that is, the spatial region of induced polarization anomaly.

[0042] The step 9 is specifically as follows: the overlapping part of the vertical projection of the plane range of the broken alteration zone circled in step 6 and the induced polarization anomaly spatial area circled in step 8 is taken as the spatial range of the deep broken alteration zone in the study area.

[0043] The beneficial technical effects of the present invention are:

[0044] 1. The present invention provides a method for locating deep fractured and altered zones of granite-type uranium deposits. By combining two geophysical methods, magnetic gradient and induced polarization sounding, with a stream sediment geochemical method, the plane and the section are combined to achieve rapid delineation of deep fractured and altered zones of granite-type uranium deposits. This method can provide important information for granite-type uranium ore exploration, especially deep prospecting in rock mass, expand prospecting space, and reduce blind drilling work.

[0045] 2. The method for locating the deep fractured alteration zone of granite-type uranium deposit provided by the present invention does not need to blindly carry out trenching and drilling on the surface compared with the existing technology. By quickly obtaining the lead isotope characteristics and magnetic gradient characteristics, the two low-cost methods are superimposed to quickly obtain the plane position of the fractured alteration zone, reducing the cost and risk of direct exploration.

[0046] 3. The present invention provides a method for locating deep fractured alteration zones in granite-type uranium deposits. It not only uses the high-value characteristics of the magnetic gradient modulus to delineate possible fractured alteration zones on the plane, but also superimposes the induced polarization sounding method for the deep, and uses high polarizability anomalies to locate the fractured alteration zones in the vertical direction, thereby spatially characterizing the distribution characteristics and positions of deep fractured alteration zones. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The present invention provides a flow chart of a method for locating deep fractured and altered zones in a granite-type uranium deposit. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0049] like Figure 1 As shown, the present invention provides a method for locating a deep fractured alteration zone of a granite-type uranium deposit, which specifically comprises the following steps:

[0050] Step 1: Determine the scope of work based on the exposure of the granite.

[0051] The research scope is determined based on the distribution of granite in the 1:50,000 or 1:200,000 geological map of the study area, and the research scope must cover the rock outcrop area.

[0052] Step 2: Carry out water system sediment sampling within the working scope determined in step 1 above.

[0053] The sampling scale of water system sediment is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 500 meters; the sampling site should be selected at the bottom of the river or the river bank where it contacts the water surface. In areas with small or intermittent water flow (dry river or valley), the sampling location needs to be at the bottom. If there is no water system in the sampling range, sampling can be done at the bottom of a smaller dry ditch, and the sampling location should not deviate from the survey line by more than 250 meters. The sampling material is mainly silt and silt, and the particle size is required to be less than the particle size of the 60-mesh sieve; the sample retention weight is not less than 150 grams.

[0054] Step 3: Analyze the collected samples, count the lead content, and determine the abnormal range of lead content.

[0055] Step 3.1: Analyze the samples collected in step 2 by atomic fluorescence spectrometry (AAS), count the lead content at each point, and obtain the lead content data Pb(i,j) at each point;

[0056] Step 3.2: Based on the lead content data at each point, calculate the lower limit of lead anomaly delineation according to the following formula:

[0057]

[0058]

[0059] In the formula,

[0060] Pb(i,j) is the lead content data of each point;

[0061] is the average value of lead content at each point;

[0062] i, j is the jth measuring point on the i-th measuring line of the sampling, there are m measuring lines and n measuring points in total;

[0063] σ is the standard deviation of the data;

[0064] A(Pb) is the abnormal lower limit of lead content.

[0065] Step 3.3: Grid the lead content data Pb(i,j) of each point using surfer software, and select the minimum curvature method as the gridding method to obtain the lead content contour map. Circle the plane area where the lead content value is higher than the abnormal lower limit of the lead content A(Pb), and record it as S(Pb), indicating that the area is the lead element abnormal range.

[0066] Step 4: Carry out ground magnetic gradient measurement within the working range determined in step 1 to obtain magnetic gradient data at each point.

[0067] The working scale of magnetic gradient measurement is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 100 meters; a GSM-19GW series magnetometer is used in gradient measurement mode. The two magnetic probes are kept horizontal, the probe directions are kept consistent, and the probe rods connecting the two probes are perpendicular to the ground, with a deflection angle of no more than 10°; the height of the lower probe from the ground is greater than 2 meters, and the distance between the upper probe and the lower probe is 0.5 meters, to obtain magnetic gradient data at each point.

[0068] Step 5: Based on the magnetic gradient data at each point, circle the area with high magnetic gradient modulus values.

[0069] Step 5.1: Using the magnetic gradient data M(i,j) of each point obtained in step 4, calculate the absolute intensity of the magnetic gradient |M|(i,j) of each point according to the following formula.

[0070]

[0071] Wherein, M(i,j) is the magnetic gradient data of each point; |M|(i,j) is the absolute intensity of magnetic gradient at each point; i and j are the jth measuring point on the i-th measuring line of the survey line; when it is the first or last measuring point, the square average of the point and the adjacent measuring points is taken as the absolute intensity of magnetic gradient at the point.

[0072] Step 5.2: Take 1.5 times the arithmetic mean of the absolute intensity of magnetic gradients at all measuring points as the anomaly lower limit L, that is,

[0073] Step 5.3: Calculate the ratio r(i,j) of the absolute intensity of the magnetic gradient at each measuring point to the lower limit of the anomaly, that is, r(i,j) = |M|(i,j) / L.

[0074] The ratio data r(i,j) of each measuring point is gridded using surfer software. The Kriging method is selected as the gridding method. The Linear variable basis function is used, the slope is 1, and the anisotropy ratio is 5. The contour map is obtained. The plane range greater than 1 in the map is circled and recorded as S(Mr), indicating that the area is a high value area of ​​magnetic gradient modulus.

[0075] Step 6: The overlapping part of the lead element anomaly range S(Pb) obtained in step 3 and the magnetic gradient modulus high value area S(Mr) obtained in step 5 is the plane range of the broken alteration zone, recorded as S(PbMr).

[0076] Step 7: Based on the planar extent of the fractured alteration zone determined in step 6, conduct induced polarization sounding.

[0077] The survey line of the induced polarization sounding work must cover the plane range of the broken alteration zone determined in step 6 and exceed the demarcated boundary by at least 2 kilometers. The survey line spacing is 500 meters and the point spacing is 50 meters. A symmetrical quadrupole device is used to obtain the polarizability values ​​of different depths of underground measuring points by changing the transmission distance at different measuring points along the survey line. The transmission distance does not exceed 2 kilometers, and the detection depth is half of the transmission distance. The polarizability values ​​of different depths of each measuring point in each profile are obtained.

[0078] Step 8: Identify the spatial region of induced polarization anomaly.

[0079] Step 8.1: Use the minimum curvature grid method to mesh the depth polarizability values ​​of each measuring point in the profile in step 7 in the Surfer drawing software to obtain the polarizability contour maps of each profile, and circle the area with a polarizability higher than 4% as the high polarizability range.

[0080] Step 8.2: According to the principle of lateral continuity, for the polarizability contour maps of each section obtained in step 8.1, connect the high polarizability range circled on each section along the shortest path to obtain the spatial distribution range V(IP) of the high polarizability region, indicating that the region is the spatial region of induced polarization anomaly.

[0081] Step 9: Locate the spatial extent of the fractured alteration zone.

[0082] The vertical projection of the plane range S(PbMr) of the broken alteration zone circled in step 6 and the overlapping part of the high polarizability spatial range V(IP) (i.e., the induced polarization anomaly spatial area) circled in step 8 are taken as the spatial range of the deep broken alteration zone in the study area.

[0083] Example

[0084] Taking the granite uranium mineralization belt in the Baishun-Xia'ejing area in the southern part of the Zhuguang rock mass as an example, the present invention provides a method for locating the deep fractured alteration zone of a granite-type uranium deposit, which specifically includes the following steps:

[0085] Step 1: Determine the scope of work based on the exposure of the granite.

[0086] The research scope was determined based on the distribution of granite in the 1:50,000 geological map of the study area, and the research scope covered the rock outcrop areas.

[0087] Step 2: Carry out water system sediment sampling within the working scope determined in step 1 above.

[0088] The sampling scale of water system sediment is 1:50,000, the distance between survey lines is 500 meters, and the distance between sampling points is 500 meters; the sampling site should be selected at the bottom of the river or the part of the river bank that contacts the water surface. In areas with small or intermittent water flow (dry river or valley), the sampling location needs to be at the bottom. When there is no water system in the sampling range, sampling is carried out at the bottom of a smaller dry ditch, and the sampling location deviates from the survey line by no more than 250 meters. The sampling material is mainly silt and silt, and the particle size is required to be less than the particle size of the 60-mesh sieve; the sample retention weight is not less than 150 grams.

[0089] Step 3: Analyze the collected samples, count the lead content, and determine the abnormal range of lead content.

[0090] Step 3.1: Analyze the samples collected in step 2 by atomic fluorescence spectrometry (AAS), count the lead content at each point, and obtain the lead content data Pb(i,j) at each point;

[0091] Step 3.2: Based on the lead content data at each point, calculate the lower limit of lead anomaly delineation according to the following formula:

[0092]

[0093]

[0094] In the formula,

[0095] Pb(i,j) is the lead content data of each point;

[0096] is the average value of lead content at each point;

[0097] i, j are the jth measuring points on the i-th sampling line. In this example, there are 50 sampling lines for river sediment sampling, and 40 measuring points on each line, that is, m = 50, n = 40;

[0098] σ is the standard deviation of the data;

[0099] A(Pb) is the abnormal lower limit of lead content.

[0100] Step 3.3: Grid the lead content data Pb(i,j) of each point using surfer software, and select the minimum curvature method as the gridding method to obtain the lead content contour map. Circle the plane area where the lead content value is higher than the abnormal lower limit of the lead content A(Pb), and record it as S(Pb), indicating that the area is the lead element abnormal range.

[0101] Step 4: Carry out ground magnetic gradient measurement within the working range determined in step 1 to obtain magnetic gradient data at each point.

[0102] The working scale of magnetic gradient measurement is 1:50,000, the spacing between survey lines is 500 meters, and the sampling point spacing is 100 meters; a GSM-19GW series magnetometer is used in gradient measurement mode. The two magnetic probes are kept horizontal, the probe directions are kept consistent, and the probe rods connecting the two probes are perpendicular to the ground, with a deflection angle of no more than 10°; the lower probe is 2.2 meters above the ground, and the upper probe is 0.5 meters away from the lower probe to obtain magnetic gradient data at each point.

[0103] Step 5: Identify the areas with high magnetic gradient modulus values.

[0104] Step 5.1: Using the magnetic gradient data M(i,j) of each point obtained in step 4, calculate the absolute intensity of the magnetic gradient |M|(i,j) of each point according to the following formula.

[0105]

[0106] Wherein, M(i,j) is the magnetic gradient data of each point; |M|(i,j) is the absolute intensity of magnetic gradient at each point; i and j are the jth measuring point on the i-th measuring line of the survey line; when it is the first or last measuring point, the square average of the point and the adjacent measuring points is taken as the absolute intensity of magnetic gradient at the point.

[0107] Step 5.2: Take 1.5 times the arithmetic mean of the absolute intensity of magnetic gradients at all measuring points as the anomaly lower limit L, that is, In this example, there are 50 measuring lines in total for magnetic gradient work, and each measuring line has 200 measuring points, that is, m = 50, n = 200;

[0108] Step 5.3: Calculate the ratio r(i,j) of the absolute intensity of the magnetic gradient at each measuring point to the lower limit of the anomaly, that is, r(i,j) = |M|(i,j) / L.

[0109] The ratio data r(i,j) of each measuring point is gridded using surfer software. The Kriging method is selected as the gridding method. The Linear variable basis function is used, the slope is 1, and the anisotropy ratio is 5. The contour map is obtained. The plane range greater than 1 in the map is circled and recorded as S(Mr), indicating that the area is a high value area of ​​magnetic gradient modulus.

[0110] Step 6: The overlapping part of the lead element anomaly range S(Pb) obtained in step 3 and the magnetic gradient modulus high value area S(Mr) obtained in step 5 is the plane range of the broken alteration zone, recorded as S(PbMr).

[0111] Step 7: Based on the planar extent of the fractured alteration zone determined in step 6, conduct induced polarization sounding.

[0112] The survey line of the induced polarization sounding work needs to cover the plane range of the broken alteration zone determined in step 6 and exceed the demarcated boundary by 2 kilometers. The survey line spacing is 500 meters and the point spacing is 50 meters. A symmetrical quadrupole device is used to obtain the polarization rate values ​​of different depths of underground measuring points by changing the transmission distance at different measuring points along the survey line. The transmission distance is 0.4-1.6 kilometers, and the receiving end is measured once every 0.2km. The detection depth is half of the transmission distance. The polarization rate values ​​of different depths of each measuring point in each profile are obtained.

[0113] Step 8: Identify the spatial region of induced polarization anomaly.

[0114] Step 8.1: Use minimum curvature to grid the depth polarizability values ​​of each measuring point in the profile in step 7 in the drawing software to obtain the polarizability contour map of each profile, and circle the area with polarizability higher than 4% as the high polarizability range.

[0115] Step 8.2: According to the principle of lateral continuity, for the polarizability contour maps of each section obtained in step 8.1, connect the high polarizability range circled on each section along the shortest path to obtain the spatial distribution range V(IP) of the high polarizability region, indicating that the region is the spatial region of induced polarization anomaly.

[0116] Step 9: Determine the spatial extent of the fractured alteration zone.

[0117] The vertical projection of the plane range S(PbMr) of the broken alteration zone circled in step 6 and the overlapping part of the high polarizability spatial range V(IP) (i.e., the induced polarization anomaly spatial area) circled in step 8 are taken as the spatial range of the deep alteration and fragmentation zone in the study area.

[0118] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. A method for locating deep fractured and altered zones of granite-type uranium deposits, characterized in that: The method comprises: Step 1: Determine the scope of work based on the exposure of granite; Step 2: Carry out stream sediment sampling within the determined working scope; Step 3: Analyze the collected samples, count the lead content, and identify the abnormal range of lead content; Step 4: Carry out ground magnetic gradient measurement within the determined working range to obtain magnetic gradient data at each point; Step 5: Based on the magnetic gradient data of each point, circle the area with high magnetic gradient modulus value; Step 6: The overlapped part of the lead element anomaly range obtained in step 3 and the magnetic gradient modulus high value area obtained in step 5 is the plane range of the fractured alteration zone; Step 7: Conduct induced polarization sounding according to the plane range of the fractured alteration zone determined in step 6; Step 8: Delineate the abnormal spatial area of ​​induced polarization; Step 9: Locate the spatial extent of the fractured alteration zone.

2. The method for locating the deep fractured alteration zone of a granite-type uranium deposit according to claim 1, characterized in that: The step 2 is specifically as follows: the water system sediment sampling work scale is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 500 meters; the sampling material is mainly silt and silt, and the particle size is required to be less than the particle size of the 60 mesh sieve; The sample retention weight shall not be less than 150 grams.

3. The method for locating the deep fractured alteration zone of a granite-type uranium deposit according to claim 1, characterized in that: The step 3 comprises: Step 3.1: Analyze the collected samples using atomic fluorescence spectrometry to obtain the lead content data at each point; Step 3.2: Based on the lead content data at each point, calculate the lower limit of lead anomaly delineation according to the following formula: In the formula, Pb(i,j) is the lead content data of each point; is the average value of lead content at each point; i, j is the jth measuring point on the i-th measuring line of the sampling, there are m measuring lines and n measuring points in total; σ is the standard deviation of the data; A(Pb) is the lower limit of abnormal lead content; Step 3.3: Grid the lead content data Pb(i,j) of each point using surfer software to obtain a lead content contour map, and circle the plane area where the lead content value is higher than the abnormal lower limit of the lead content A(Pb), which is recorded as the lead element abnormal range.

4. The method for locating the deep fractured alteration zone of a granite-type uranium deposit according to claim 1, characterized in that: The step 4 is specifically as follows: the working scale of the magnetic gradient measurement is 1:50,000, the survey line spacing is 500 meters, and the sampling point spacing is 100 meters; a GSM-19GW series magnetometer is used, the gradient measurement mode is used, the two magnetic probes are kept horizontal, the probe directions are kept consistent, and the probe rods connecting the two probes are perpendicular to the ground, and the deflection angle does not exceed 10°; the height of the lower probe from the ground is greater than 2 meters, and the distance between the upper probe and the lower probe is 0.5 meters, and the magnetic gradient data of each point is obtained.

5. The method for locating the deep fractured alteration zone of a granite-type uranium deposit according to claim 4, characterized in that: The step 5 comprises: Step 5.1: Using the magnetic gradient data of each point obtained in step 4, calculate the absolute intensity of the magnetic gradient at each point according to the following formula: Where, M(i,j) is the magnetic gradient data of each point; |M|(i,j) is the absolute intensity of magnetic gradient at each point; i and j are the jth measuring point on the i-th measuring line of the sampling of the measuring line; when it is the first or last measuring point, the square average of the point and the adjacent measuring points is taken as the absolute intensity of magnetic gradient at the point; Step 5.2: 1.5 times the arithmetic mean of the absolute intensity of magnetic gradients at all measuring points is taken as the anomaly lower limit L; Step 5.3: Calculate the ratio r(i,j) of the absolute intensity of the magnetic gradient at each measuring point to the lower limit of the anomaly; The ratio data r(i, j) of each measuring point is gridded using surfer software to obtain a contour map. The plane range greater than 1 in the map is circled and recorded as the high-value area of ​​the magnetic gradient modulus.

6. The method for locating deep fractured and altered zones of granite-type uranium deposits according to claim 1, characterized in that: The specific steps of step 7 are as follows: the survey line of the induced polarization sounding work needs to cover the plane range of the broken and altered zone determined in step 6, and exceed the demarcated boundary by at least 2 kilometers; the survey line spacing is 500 meters, and the point spacing is 50 meters; a symmetrical quadrupole device is used to obtain the polarization rate values ​​of different depths of underground measuring points by changing the transmission distance at different measuring points along the survey line. The transmission distance does not exceed 2 kilometers, and the detection depth is half of the transmission distance, so as to obtain the polarization rate values ​​of different depths of each measuring point in each profile.

7. A method for locating deep fractured and altered zones of granite-type uranium deposits according to claim 6, characterized in that: The step 8 comprises: Step 8.1: Use the minimum curvature grid method to grid the depth polarizability values ​​of each measuring point in the profile in step 7 in the drawing software to obtain the polarizability contour map of each profile, and circle the area with a polarizability higher than 4% as the high polarizability range; Step 8.2: Connect the high polarizability ranges circled on each section along the shortest path to obtain the spatial distribution range of the high polarizability region, that is, the spatial region of induced polarization anomaly.

8. The method for locating deep fractured and altered zones of a granite-type uranium deposit according to claim 1, characterized in that: The step 9 is specifically as follows: the overlapping part of the vertical projection of the plane range of the broken alteration zone circled in step 6 and the induced polarization anomaly spatial area circled in step 8 is taken as the spatial range of the deep broken alteration zone in the study area.

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