Large-scale denudation depth thematic mapping method

Abstract

To provide a large-scale denudation depth thematic mapping method.SOLUTION: There is provided a large-scale denudation depth thematic mapping method. The denudation depth mapping method includes: creating a rule for arranging points and lines of a research area, a field sampling rule, a field observation and recording rule and a mineral processing rule; applying a field thermochronology research method to measure and analyze target minerals selected at each field work point; inputting analysis data into improved Low Thermo software, and performing thermal evolution history simulation analysis and denudation depth calculation to obtain a denudation depth at each of the field work point; drawing a denudation depth isopleth map of the research area according to the denudation depth at each field work point; and and, using a large-scale standard map width regional geological map of the research area as a base map, superimposing the base map and the denudation depth isopleth map to acquire a denudation depth map of the research area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of denudation depth mapping, and in particular to a method for large scale mapping of denudation depth as a subject. [Background technology]

[0002] After geological formation, geological bodies rarely remain stationary over the long term of their geological history. They usually undergo movement due to tectonic activity, which can be either horizontal or vertical. While horizontal movement of geological bodies is more highly valued in the field of geological structure research, vertical movement of geological bodies is more prominent in regional geological and mineral deposit research. Intrusive rocks, altered rocks, and metal deposits usually form several kilometers to tens of kilometers underground. Later tectonic activity causes geological bodies to be uplifted and then denuded by erosion. Studying the uplift and denudation processes of geological bodies is of dual importance: it sheds light on the regional geological evolution history (earth structure) and studies mineralization laws to promote mineral exploration. (1) Regional Geological Significance. The uplift of geological bodies is usually caused by tectonic activity. Studying the uplift and denudation processes of geological bodies allows for inverse analysis of the nature, scale, and process of tectonic events, thereby providing qualitative and quantitative constraints on the regional geological evolution process. (2) The significance of studying the formation, preservation, and evolution of mineral deposits. Metallographic research not only focuses on the origin and formation of mineral deposits, but also considers their post-formation preservation and evolution. Different mineral deposit types, production characteristics, tectonic activity, paleoclimate and paleoenvironment, uplift, and denudation all contribute to the factors that influence mineral deposit preservation and evolution. Overall, mineralogy changes are, first, changes experienced by the mineral deposits and ore bodies themselves, and second, changes in the environment and spatial location of the mineral deposits. The preservation of mineral deposits largely depends on the weathering and denudation history of the overlying rocks, and the formation of large mineral deposits is closely related to the preservation conditions of their tectonic environment. Quantitative calculations of the uplift and denudation of mineral deposits and regional geological bodies within a mine belt allow for a comprehensive assessment of the preservation and evolution of mineral deposits in the mine belt and can guide regional mineral exploration.

[0003] From the above, it can be seen that developing regional denudation depth mapping and more precisely depicting the variations in denudation depth at different sites within the region is not only theoretically important for the study of regional geological evolution, but also has practical value for regional mineral exploration breakthroughs.

[0004] Furthermore, denudation depth mapping, such as regional mapping at 1:50,000, 1:200,000, or 1:250,000 scales, on a national or even global scale can comprehensively reveal the vertical change process of the Earth's surface from a macroscopic perspective, retracing the evolutionary history of the Earth's deep structure internally. Externally, it can explore the constraints of topographic changes on changes in the hydrosphere and atmosphere, providing new tools for studying the co-evolution of the Earth's various geological layers. Thermochronological geological mapping includes maps of uplift rates, regional denudation rates, and regional denudation depth (denudation volume). Internationally, such mapping scopes are very large, usually covering entire islands or even entire countries, so they are often created as small-scale maps, which are relatively easy to operate. From a practical standpoint, they are only useful for observing general change trends within large regions and have no practical value. In Japan, there have been many achievements in thermochronological research, but very few in the study of thermochronological mapping. Only a few thermochronological maps of scattered mining areas have been published, but they are all small-scale and non-normative maps without rules.

[0005] Currently, no one has carried out the mapping of denudation depth of geological bodies at large scales such as 1:50,000 and 1:200,000 with standard base maps, either domestically or abroad. Therefore, it is extremely urgent to explore methods for mapping denudation depth at large scales such as 1:50,000, 1:200,000, and 1:250,000 with standard base maps, establish technical specifications for mapping denudation depth of geological bodies using thermochronology methods, and lay the foundation for the deployment of denudation depth mapping at large scales such as 1:50,000, 1:200,000, and 1:250,000 with standard base maps nationwide and even around the world. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a large-scale mapping method for denudation depth, which can achieve mapping of denudation depth of geological bodies at large scales such as 1:50,000 and 1:200,000 with standard base maps. The data in the obtained denudation depth map is more accurate and in line with the actual situation, which can provide a more realistic and accurate comprehensive assessment of the conservation and change state of mineral deposits in mining belts and can guide regional mineral exploration and prospecting. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides the following solutions.

[0008] 1. A method for large-scale mapping of denudation depth, the method comprising: Creating a rule for arranging field work points and work routes in the research area, and creating a rule for sampling the field work points; To develop field observation and recording rules applicable to thermochronological research and to establish mineral processing rules; applying thermochronological research methods to measure and analyze selected target minerals at each of said field work points to obtain basic analytical data; The basic analysis data is input into the improved Low Thermo software to perform thermal evolution history simulation analysis and denudation depth calculation, and obtain the denudation depth at each of the field work points; and the improved Low Thermo software increases the K-feldspar Ar-Ar, plagioclase Ar-Ar, and amphibole Ar-Ar dating results based on the conventional Low Thermo to become simulation parameters; The method includes drawing contour maps of denudation depth in the research area according to the denudation depth at each of the field work points, and using a geological map of the research area with a standard map width of 1:50,000 or 1:200,000 as a base map, overlaying the base map and the contour maps of denudation depth to obtain a denudation depth map of the research area.

[0009] Optionally, creating point and line placement rules for field work points and work routes in the study area, specifically: Setting the field work points according to the accuracy of thermochronological analysis, the distribution characteristics of lithology, point representativeness and uniformity; and setting the work route in accordance with the distribution of the outdoor work points.

[0010] Optionally, creating a field sampling rule for sampling at the field work point specifically includes: In the case of intrusive rocks, for "stock-like rock bodies" with an exposed area of ​​less than 5 km2, one thermochronological sample shall be collected according to the surface exposure conditions and sampling convenience; In the case of a "flat rock body" in an intrusive rock, the elevation range within the exposed area is less than 400 meters. If the "flat rock body" is a convergent rock body, 1-2 thermochronological research samples shall be collected, and the sampling locations shall be the center of the rock body, the highest point of the exposed rock body, the edge of the rock body, or the lowest point of the exposed rock body. If the "flat rock body" is a strip-shaped rock body, 1-3 thermochronological research samples shall be collected, and the sampling locations shall be the center and both ends of the rock body. Convergent rock body refers to a circular, elliptical, rectangular, etc. For the "three-dimensional rock body" in the intrusive rock, a series of thermochronological research samples should be collected at an elevation difference of 300-400 meters, and the sampling density should be increased at both ends of the rock body. The elevation range within the rock body exposure range of the "three-dimensional rock body" should be greater than 400 meters. In the case of a fault zone, setting control points along the fault zone at the center and both ends of the fault zone, and collecting thermochronological study samples on both sides of the fault at the control points; In the case of shear zones, establishing three control points along the shear zone at the center and both ends of the shear zone and collecting at least one thermochronological sample in each shear zone; In the case of altered strata, depending on the exposure conditions of the altered strata, thermochronological study samples should be collected according to the sampling rules of the intrusive rocks; In the case of sandstones and shallow metamorphic rocks in sedimentary formations, collecting lithology control samples or, depending on the lithology and exposure conditions, collecting thermochronological study samples with reference to the sampling rules for intrusive rocks; In the case of continuous thermochronological sections, this involves selecting one or two sections with large differences in elevation above sea level within the map area, collecting thermochronological research samples according to the predetermined elevation differences, and creating a thermochronological section.

[0011] Optionally, develop field observation and recording rules to apply to thermochronological studies, specifically: Dividing the field operation points into geological control points and geological observation points, and setting data description requirements for the geological control points and the geological observation points; and establishing the format and content of the field logbook.

[0012] Optionally, the establishment of mineral processing rules specifically includes: When crushing the target minerals, it is necessary to use pollution-free equipment and strictly prevent cross-mixing of samples. When selecting single minerals such as zircon, apatite, and titanite, the completeness of the crystal form must be ensured, the sample must be crushed within a short time, and multiple sieving processes are required. The sample must not be heated to high temperatures and baked, and the heating temperature must not exceed 45°C. More than 1,000 grains of each single mineral must be selected. When sorting silicate minerals, it is strictly forbidden to contaminate them with organic matter during sorting, and the particle size must be 60-80 mesh, the purity must be 99% or more, and the amount of each single mineral sorted must be 3 grams or more. The silicate minerals include amphibole, biotite, potassium feldspar, plagioclase, and borosilicate.

[0013] Optionally, applying thermochronological research methods to measure and analyze selected target minerals at each of said field work points to obtain basic analytical data may specifically include: The target minerals selected at the field work points are subjected to dating analysis using zircon and apatite (U-Th) / He, dating analysis using apatite division tracking, dating analysis using potassium-containing silicate minerals Ar-Ar method, dating analysis using zircon U-Pb method, and whole-rock component analysis to obtain the basic analysis data, and the basic analysis data includes thermochronological analysis measurement data and component analysis data of the target minerals at each of the field work points.

[0014] Optionally, the basic analytical data at each of the field work points is input into the improved Low Thermo software to perform thermal evolution history simulation analysis and denudation depth calculation, and obtain the denudation depth at each of the field work points.

[0015] Optionally, drawing a contour map of denudation depth in the research area according to the denudation depth at each of the field work points, and using a geological map of the research area with a standard map width of 1:50,000 or 1:200,000 as a base map, overlaying the base map and the contour map of denudation depth to obtain a denudation depth map of the research area, specifically: constructing a TXT document based on point information and the denudation depth at each of the field work points; processing said TXT document in MAPGIS software by selecting "Discrete Data Grid Type"; According to the processed TXT document, drawing the contour map of said denudation depth using the "plane contour drawing" function in MAPGIS software; Using the "Image Analysis" function in the "Image Processing" section of MAPGIS, vectorize the geological map of the standard map width area of ​​1:50,000 or 1:200,000, and use the vectorized geological map as the base map. and applying the denudation depth contour map to the corresponding area of ​​the base map to obtain the denudation depth map. [Effects of the Invention]

[0016] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention provides a large-scale mapping method for the theme of denudation depth, and establishes the field work point and work line point and line arrangement rules, field sampling rules, field observation and recording rules and mineral processing rules for the research area. The thermochronological research method is applied to measure and analyze the target minerals selected at each field work point, obtain basic analytical data, and convert the basic analytical data into an improved Low The thermal evolution history simulation analysis and denudation depth calculation were performed using Thermo software to obtain the denudation depth at each field work point. Denudation depth contour maps of the study area were then drawn according to the denudation depth at each field work point. Using the large-scale standard regional geological map of the study area as the base map, the base map and the denudation depth contour map were overlaid to obtain a denudation depth map of the study area. This achieved mapping of the denudation depth of geological bodies with large-scale standard base maps, such as 1:50,000 and 1:200,000. The data in the obtained denudation depth map is more accurate and in line with the actual situation, which allows for a more realistic and accurate comprehensive assessment of the preservation and evolution of ore deposits in the mining belt, and can also guide regional mineral exploration and prospecting. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a flowchart of a large-scale mapping method for denudation depth provided by an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram of a thermal evolution history forward modeling window provided by an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram of a thermochronology method selection window provided by an embodiment of the present invention. [Figure 4] FIG. 1 is a schematic diagram of a chronology data input window for thermal evolution history simulation provided by an embodiment of the present invention. [Figure 5] FIG. 1 is a schematic diagram of a U-Th / He parameter setting window provided by an embodiment of the present invention. [Figure 6]FIG. 1 is a schematic diagram of a division tracking parameter setting window provided by an embodiment of the present invention. [Figure 7] FIG. 1 is a schematic diagram of a thermal evolution history inversion window provided by an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of a one-dimensional denudation calculation window provided by an embodiment of the present invention. [Figure 9] 1 is a schematic diagram of a one-dimensional denudation calculation parameter input window provided by an embodiment of the present invention; [Figure 10] 1 is a schematic diagram of a two-dimensional denudation and paleotopography simulation window provided by an embodiment of the present invention. FIG. [Figure 11] 1 is a schematic diagram of a two-dimensional denudation calculation parameter input window provided by an embodiment of the present invention; [Figure 12] FIG. 1 is a thermal evolution history curve diagram (path display) provided by an embodiment of the present invention. [Figure 13] FIG. 1 is a thermal evolution history curve diagram (conventional style representation) provided by an embodiment of the present invention. [Figure 14] FIG. 2 is a reverse-direction thermal evolution history curve diagram provided by an embodiment of the present invention; [Figure 15] 10 is a diagram illustrating a calculation result of erosion depth (erosion amount) provided by an embodiment of the present invention. [Figure 16] FIG. 1 is a schematic diagram illustrating drawing parameter settings for a planar contour map provided by an embodiment of the present invention; [Figure 17] 1 is a geological base map library established by the MAPGIS standard map format provided by an embodiment of the present invention; [Figure 18] FIG. 1 is a schematic diagram of introducing a denudation volume contour map provided by an embodiment of the present invention into a MAPGIS version geological base map. DETAILED DESCRIPTION OF THE INVENTION

[0018] The above drawings are intended to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art. Obviously, the above drawings are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative efforts.

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments, and all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the protection scope of the present invention.

[0020] There are several methods for studying the denudation depth (denudation volume) of geological bodies, but thermochronology is the most effective and provides more accurate quantitative results. Thermochronology, also known as isotope thermochronology, is an emerging, comprehensive field that combines traditional isotope chronology with other disciplines. Thermochronology provides comprehensive information on time, temperature, spatial location, and other parameters, allowing for precise characterization of the thermal evolution and spatial location changes experienced by geological bodies during their formation and later stages. Its basic principle is to utilize the principles of radioactive isotope decay and the differences in closure temperatures of different isotope systems to perform dating analysis on minerals. The information contained therein, such as time and temperature, can be used to study the thermal evolution processes experienced by geological bodies, such as mountain building, the history of rock exhumation and cooling, the history of uplift and denudation, and the geothermal evolution of sedimentary basins. The core concepts are closure temperature and cooling age. The important pillars of this research are dating techniques such as (U-Th) / He, FT (fission tracking), Ar-Ar, and U-Pb, as well as computer simulation techniques for thermal evolution history.

[0021] The present invention aims to provide a large-scale mapping method for denudation depth, which can achieve mapping of denudation depth of geological bodies with large scales such as 1:50,000 and 1:200,000 and standard base maps.

[0022] In order to make the above objects, features and advantages of the present invention more apparent and comprehensible, the present invention will be described in more detail below with reference to the drawings and detailed description of the invention.

[0023] Example As shown in FIG. 1, this embodiment provides a large-scale mapping method for denudation depth, which includes:

[0024] S1: Create rules for placing points and lines for field work points and work routes in the study area. Solution design and work preparation: 1. Select the research area, i.e., the mapping area. 2. After selecting the mapping work area, comprehensively collect previous work results related to that area and the adjacent areas, including but not limited to regional geological survey reports, thematic research reports, mining area geological survey reports, scientific research papers and other literature, etc. Comprehensively analyze and organize the results obtained from previous materials to understand the geological location of the mapping area, regional geological structural characteristics, regional geological evolution history, distribution range, type and occurrence of important geological bodies such as intrusive rocks, etc. 3. Prepare a working base map. Prepare a standard-scale regional geological map at the appropriate scale (1:50,000, 1:200,000, or 1:250,000) that covers the entire mapping area. After digitization, integrate it into the digital geological mapping system. Because the target of the work is mapping denudation depth (denudation volume), mapping of this topic must be established based on previous regional geological survey work and the accuracy of previous regional geological maps at the appropriate scale (1:50,000, 1:200,000, or 1:250,000) is a prerequisite. These standard-scale geological maps have two uses: (1) as handheld geological maps (working maps) during field work, and all field geological surveys, point placement, line placement, etc. are based on these maps; and (2) as base maps when the final denudation depth map is completed. 4. Prepare a topographic map (optional). Prepare a topographic map of the corresponding scale according to the scale of the denudation depth map created according to the plan. There are two sources of topographic maps: (1) Purchase. (2) Create. Collect and download DEM digital topographic maps of the study area, import the data into Global Mapper to create contour lines, output in vector format and convert into Mapgis file, thereby obtaining a topographic map with contour lines, and then create a field work base map. 5. Prepare field tools: traditional tools such as a geological hammer, compass, and magnifying glass, as well as cameras, GPS, palmtop computers, laptops, and sample bags (each with different specifications, for hand specimens, chemical analysis samples, and large samples).

[0025] Specific rules for outdoor point and line placement: Field work is carried out in the selected mapping research work area, and field work points and field work routes are first set, that is, point placement and line placement must be carried out first, and then field work can be carried out according to the placed points and lines.Before this, there are no existing field point placement and line placement rules for large-scale mapping of denudation depth, so through exploration, practice and innovative research, field point placement and line placement rules for denudation depth mapping are established. The biggest difference between thematic mapping and regional mapping is that field point and line placement studies do not require a fixed numerical grid system. Instead, field survey routes and observation points must be selected based on the research objectives and the actual geological conditions of the region. For thermochronological studies such as denudation depth measurement, the relevant "events" are linked and consistent within a given region, so there is no need to emphasize the constraints of survey routes or the density of field observation points. Particular attention should be paid to the distribution and representativeness of points, as there is point distribution in all different parts of the map (center, squares). The main issues to consider when conducting thermochronological studies and thematic mapping line and point placement are representativeness, followed by uniformity of point distribution, and finally point density. Field work points are divided into geological control points and observation (research) points. The number of points can be as many as possible, but should be significantly less than the number required by regional geological survey mapping. Depending on the analytical accuracy of current low-temperature thermochronology, when completed within a standard 1:50,000 map area, 15-20 valid thermochronology data points can meet the requirements, corresponding to more than 40 field observation (research) points. When completed within a standard 1:200,000 or 1:250,000 map area, 25-30 valid thermochronology data points can meet the requirements, corresponding to more than 60 points requiring field observation (research). There are no fixed requirements for the design and quantity of field geological investigation routes, and the basis for route design is the arranged points. In short, the principle of field line and point placement for mapping denudation depth is to set the line according to the point distribution, taking into consideration the accuracy of thermochronological analysis, the representativeness and uniformity of the distribution points of lithology.

[0026] S2: Create field sampling rules for sampling at the field work points. Denudation depth mapping is completed by analyzing geological samples to obtain the denudation volume, and relevant samples must be collected in the field for thermochronology and other analytical research. Compared with regional geological mapping and regional exploration mapping, denudation depth mapping is very specific, and the field sampling rules for previous mapping methods are not applicable. Through exploration, research, and practice, field sampling rules for large-scale denudation depth mapping have been established. First, the accuracy of basic research results on lithology, lithology, strata, structure, etc. in regional geological maps of 1:50,000, 1:200,000, or 1:250,000 is recognized. Based on this, field sampling rules corresponding to different geological units are formulated.

[0027] (1) Field sampling rules for intrusive rocks 1. In principle, each rock body has a sample control 2. For each type of rock involved, a set of elemental research samples should be collected, with 5-10 samples (the specific number is determined according to the importance of the rock body), each weighing 200-500 grams. If the set of rock has multiple exposures, elemental research samples should be collected for each of the multiple exposures, with a total of 5-10 samples. 3. For small rock masses (stocks) with an exposed area of ​​less than 5 km2, taking into consideration the surface exposure conditions and the convenience of sampling, one thermochronological sample (specially processed in the case of steep exposure) will be collected. 4. Sampling rules for "flat rock bodies": For flat exposed rock bodies (those with an elevation range of less than 400 meters within the exposed area), different sampling rules are adopted depending on their morphology: (1) For convergent morphology rock bodies (referring to rock bodies that are circular, elliptical, rectangular, etc.), one to two thermochronological samples should be taken at the center of the rock body (or the highest exposed point) and the edge of the rock body (or the lowest exposed point). (2) For strip-shaped rock bodies, one to three thermochronological samples should be taken at the center and both ends of the rock body. 5. Sampling rules for three-dimensional rock bodies: For three-dimensional exposed rock bodies (where the elevation range within the exposed area is greater than 400 meters), the principle is to collect series thermochronological research samples at an elevation difference of 300-400 meters, and the sampling density can be appropriately increased at both ends of the rock body.

[0028] (2) Field sampling rules for fault zones If there is a significant fault zone in the area (one that penetrates the area, or has significant structural limits, or where the rock ages of the rocks on either side of it differ), control points should be set up along the fault zone at its center and both ends, and thermochronological samples should be collected on both sides of the fault at the control points. The collection of such samples can be considered comprehensively together with the collection of intrusive and altered rock samples. (3) Field sampling rules for shear zones Three control points will be set along the shear zone, at its center and at both ends (or on both sides), and at least one thermochronological sample will be collected in each shear zone, striving to collect highly deformed rock samples. (4) Field sampling rules for altered strata In the case of altered strata such as Pt old basement rocks and other altered rocks, thermochronological study samples are collected according to the sampling rules for intrusive rocks, depending on their exposure conditions. (5) Field sampling rules for sedimentary strata For sandstones and shallow metamorphic rocks in sedimentary formations, only lithology control samples should be collected under normal circumstances. If necessary, thermochronological study samples should be collected according to the lithology and exposure conditions, referring to the sampling rules for intrusive rocks. (6) Field sampling rules for continuous thermochronological sections Within the map area, select one or two sections with large elevation differences, and collect thermochronological research samples according to a certain elevation difference (300 to 400 meters) to create a thermochronological section. Within the section, the sampling density can be appropriately increased at the low and high elevation ends. (7) Suggested sampling volume for various types of rock samples (Note: For important samples, the sampling volume should be appropriately increased, even doubled) 1. Intrusive rocks: ~5kg, 2. Basic rocks: >20kg, 3. Pt-altered rocks (gneiss, amphibolite, etc.): 5-10kg, 4. Other altered rocks: allowance, 5. Sandstone: 5-10kg.

[0029] S3: Develop field observation and recording rules applicable to thermochronological research. Field observation and recording is one of the basic tasks for mapping denudation depth. Based on the contents of regional geological survey records, and combining the special requirements of denudation depth mapping and thermochronological research, the following field recording rules have been researched, formulated, and adopted: Requirements for classification and description of geological points, format and content of field record books: Geological points are divided into general geological control points and observation (research) points. 1. Geological control points: These are points on the general normal geological observation route, and their observation content is general and can be explained briefly accordingly. They serve as memory aids and a stage for dramatic scenes. Geological control points usually only collect specimens by hand, and do not conduct further sampling. 2. Observation (research) points: These are extracts that describe field geological phenomena, and are mostly analytical measurement sampling points. Important geological phenomena such as discovered geological boundaries, mapping unit boundaries, unconformity situations, and intrusion into contact boundaries will be explained as much as possible, as well as exposed areas such as important upper (lower) indicating structures, typical geological phenomena such as typical wrinkle structures, ductile shear zones, and slip surfaces, important primary structures, secondary structures and their structural indicating elements, and special geological boundaries such as fault zones and thrust structures. The explanation will focus on the relevant conditions of the field sampling points and the conditions of the collected rock samples, such as structure, weathered surface color, fresh surface color, main mineral components and their approximate contents.

[0030] S4: Establish mineral processing rules. After collecting rock samples in the field, they must be processed indoors, including sample crushing and single mineral sorting, to select single minerals for analytical measurements such as thermochronology. Due to the special nature of thermochronology analysis, special rules and requirements are also established for single mineral sorting based on the normal process. 1. First, sample crushing. When crushing rocks, it is necessary to use pollution-free equipment and strictly prevent cross-mixing of samples. 2. Selecting single minerals, such as zircon, apatite, and titanite: Ensure the integrity of the crystal structure as much as possible, crush the sample for a short time, and sift multiple times. Avoid crushing the sample into small pieces in one go, which may result in large particles of zircon or apatite being crushed. Do not heat or bake at high temperatures! (The sample heating temperature should not exceed 45°C! It is best to air dry.) For each single mineral, it is necessary to select more than 1,000 grains. 3. To separate silicate minerals such as amphibole, biotite, potassium feldspar, plagioclase, and glass feldspar, it is strictly forbidden to contaminate them with organic matter during separation. The particle size must be 60-80 mesh, and the purity must be above 99%. In principle, each single mineral must weigh at least 3 grams.

[0031] S5: Apply thermochronological research methods to measure and analyze selected target minerals at each of the above field work points to obtain basic analytical data. The basic analytical data required for the denudation depth mapping laboratory are mainly thermochronological analysis data, followed by elemental analysis data. In "Step 3," after obtaining analytical measurement targets such as various single minerals, a high-quality laboratory is selected to carry out the relevant analytical measurements. 1. Zircon and apatite (U-Th) / He dating analysis. He was extracted by laser heating, and U and Th were extracted by chemical decomposition. Single-granule mineral (U-Th) / He dating analysis of zircon and apatite samples was performed. Three to five granules were analyzed for each zircon sample, and five granules for each apatite sample. 2. Apatite fission tracking dating analysis. Fission tracking (FT) dating is performed on apatite samples, preferably by ICP-MS plasma mass spectrometry, or more preferably by conventional external detector methods. For conventional external detector methods, at least 30 granules are analyzed, and for LA-ICP-MS plasma mass spectrometry, at least 40 points are analyzed. 3. Ar-Ar dating analysis of potassium-bearing silicate minerals. Potassium-bearing silicate minerals such as amphibole, biotite, muscovite, potassium feldspar, and plagioclase were selected from the research samples and subjected to Ar-Ar dating analysis using a stepwise heating technique to obtain age spectra and isoclones. 4. Zircon U-Pb Dating Analysis. LA-ICPMS laser plasma mass spectrometry (LA-ICPMS) was used to perform U-Pb dating analysis of the zircon samples. 200 grains were carefully selected for each sample as targets. Individual zircon minerals were polished to 1 / 3 to 1 / 2 of their original size. Cathode luminescence, transmissive, and reflected light photographs were taken. Clear, endless belt sections were selected for zircon dating analysis. Each sample had more than 20 valid dating analysis points. Measurements included 207Pb / 206Pb, 207Pb / 235U, 206Pb / 238U, and 208Pb / 232Th isotope ratios and ages, as well as elemental contents such as SiO2, Ti, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Th, and U. 5. Analysis of whole rock components. Whole rock samples crushed to 200 mesh will be subjected to major and trace element analysis, as well as isotope analysis of Sr, Nd, etc., to obtain chemical composition and isotope data for the research samples.

[0032] S6: The basic analysis data is input into the improved Low Thermo software to perform thermal evolution history simulation analysis and denudation depth calculation, and the denudation depth at each of the field work points is obtained. The improved Low Thermo software increases the K-feldspar Ar-Ar, plagioclase Ar-Ar, and amphibole Ar-Ar dating results based on the conventional Low Thermo as simulation parameters. The thermal history simulation and denudation volume calculation process are explained using the Low-T Thermo software as an example. The main functions and applications of the "Low-T Thermo" thermochronological simulation software are: (1) Low-temperature chronological thermal history simulation (including apatite and zircon (U-Th) / He, apatite and zircon fission tracking, mica Ar-Ar, potassium feldspar Ar-Ar, plagioclase Ar-Ar, amphibole Ar-Ar, bedrock quartz photoluminescence, vitrinite reflectance, and a combination of the above methods) for recovering the thermal history of orogenic belts and basins; (2) Period-specific quantitative denudation calculation based on thermal history for studying denudation depth of geological bodies and ore deposit preservation conditions; (3) Paleotopography simulation based on thermal history for studying paleotopography recovery, etc. The initial version of this software used the Ar-Ar thermochronology method for thermal history simulations, applying only biotite Ar-Ar dating. The Ar isotope closure temperature interval for biotite (310-345°C) is significantly different from the zircon U-Pb closure temperature (800°C), which can easily cause distortions in the high-temperature thermal history simulations. At the same time, the Ar isotope closure temperature interval for biotite is also significantly different from the zircon He closure temperature (200°C), which can easily cause distortions in the mid-temperature thermal history simulations. The software has been modified to include additional K-feldspar Ar-Ar, plagioclase Ar-Ar, and amphibole Ar-Ar dating data as simulation parameters, further improving the accuracy of the mid- to high-temperature thermal history simulations and enabling more accurate denudation depth values. In the improved software, there are nine different thermochronology methods used for thermal history simulation. These nine methods can be selected arbitrarily, including single or multiple selections. Theoretically, there are 255 combination modes, including single method selection.

[0033] (1) Installation Low-T Thermo is compiled using Mathematica and VB.net under the Microsoft Windows operating system. Therefore, before use, you must install Mathematica 10.0 and copy Wolfram.NETLink.dll to the directory containing the main program Low.exe. You also need Microsoft .NET Framework 2.0 or later. (2) Program interface and usage overview 1. Thermal history forward modeling window, shown in Figure 2. After inputting the Time (Ma), the corresponding Temperature (oC) and other parameters, press the "Start Modeling" button to output the age and length distribution results corresponding to the input thermal history curve. 2. Thermochronology method selection window, shown in Figure 3. In this window, there are nine different thermochronology methods used for thermal history simulation. The nine methods can be selected arbitrarily, including single or multiple selections. Theoretically, there are 255 combination modes, including a single method selection. The output directory is used to place all calculated and derived data and graphic files. 3. Input window, as shown in Figure 4. After selecting a different thermochronological method, click "Next" to enter the input window and enter the corresponding experimental data and parameters. Each data input box corresponds to a notepad, and the data can be edited arbitrarily. This facilitates copying and pasting data from other software, allowing further editing as needed. For specific input formats, refer to the previous data format examples, and simply replace the example data when entering data. Multi-line input can be started by pressing the Enter key. There can be one or more spaces between data, and you can also press the Tab key to create a space. For the U-Th / He method, the stopping distance of alpha particles can be selected using the Farley et al. (1996) or Ketcham et al. (2011) modes. For many granules, "Using multiple ages one by one" can be selected, in which each granule is used to screen the hypothetical paths one by one. Alternatively, "Using multiple ages together" simulation can be selected, in which each granule is used to screen the hypothetical paths together, ultimately achieving the average acceptable GOF range. "Using mean age" is used to select the average age of all granules to screen the hypothetical paths, as shown in Figure 5. "Number of grids for R" is used to set the number of finite difference nodes. The default is 20, and the maximum setting is 100. The larger the value, the denser the grid and the greater the accuracy, but the slower the calculation. This value has a limited effect on the calculation results of the (U-Th) / He simulation age, so usually setting it to 20 will meet most needs. "Show modeled He age distribution" is used to set whether to display the distribution of He granule ages according to the effective uranium concentration. For the split tracking method, "Default Lo(c) constant value (μm)" is the default Lo(c) (initial closed tracking length by projection calibration). "Lo(c)=" is used to set the Lo(c) value via Dpar (μm). "Restore Default" restores the default setting, as shown in Figure 6. For vitrinite reflectance %Ro, the calibration modes include EASY%Ro (Sweeney and Burnham, 1990), IKU%Ro (Ritter et al., 1996), and basin%Ro (Nielsen et al., 2016). 4. The main window (thermal history inversion window) is shown in Figure 7. "Ts (℃, at sea level)": Surface temperature at sea level (unit: Celsius). "Elevation (m)": The height at which the sample is located. The default atmospheric vertical temperature gradient is 6°C / km. "Tmax (℃)": Maximum ordinate value. Since the ordinate in the thermal history simulation output diagram is temperature, it is necessary to set the coordinate axis display range. "Duration (Ma)": Maximum abscissa value. Since the ordinate in the thermal history simulation output diagram is time, it is necessary to set the coordinate axis display range. 'Paths Tried': The number of thermal history paths searched during inversion, usually 10,000 (which can be self-defined according to actual needs). "Acceptable Fit": The acceptable goodness of fit (GOF), which is usually 0.05. You can set it yourself according to your actual needs. "Interval nodes": When the user provides constraint boxes according to the background information such as actual geological conditions, it is the number of nodes between every two adjacent constraint boxes, for example, three. "Nodes when no box": The number of nodes in each random path when there is no constraint box (for example, take 10). "Box (timemin, timemax, Tempmin, Tempmax)": If there is a constraint box, enter the time and temperature range of the constraint box here. Enter the minimum time value in "timemin," the maximum time value in "timemax," the minimum temperature value in "Tempmin," and the maximum temperature value in "Tempmax." Each constraint box occupies one line. If there are multiple lines, press the Enter key to change lines. The "Clear All" button is used to remove all previous parameter entries. The "Save as default" button is used to save all previous parameter inputs and make them the default inputs for the next simulation. "Preview boxes distribution" Preview the constraint boxes. "Start Modeling": Starts the inversion simulation button. "Terminate" Ends Inversion Simulation Button. If there is an execution error or you do not have time to wait for the program to run, you can press this key to stop the inversion and end the simulation. "Modeled Result": This box is used to display the thermal history simulation results. "Default display": Default style display. Selecting this option will display all acceptable paths. The black line is the average result of all acceptable paths. "Traditional display": Traditional style display. Selecting this option displays only the boundaries of all acceptable paths, similar to the display style of AFTSolve (Ketcham et al., 2000) and HeFTy (Ketcham, 2005). The green range represents the acceptable range (GOF ≥ Acceptable Fit). The pink range represents the high accuracy range (GOF ≥ 0.5). If a high accuracy range exists, the black line is the average result of paths that fall within all high accuracy ranges; otherwise, the black line is the average result of all acceptable paths. "Modeled He age distribution" is used to display the distribution of He granule ages according to the effective uranium concentration. The radiation damage accumulation and annealing model for apatite employs RDAAM (Flowers et al., 2009), and the radiation damage accumulation and annealing model for zircon employs ZrRDAAM (Guenthner et al., 2013). "Modeled AFT length distribution" is used to display the length distribution of the sealed traces of the apatite fission traces. In the text boxes on the right, the age values ​​corresponding to the thermal history simulation results (i.e., black lines) of the different selected thermochronological methods are displayed. "Modeled Report" is used to display the detailed calculation process and report related information. When "The end" or "No Result" appears, it means the simulation is finished. After the thermal history simulation is completed, the graphics are finally output in ".pdf" format and saved in the output directory initially set by the user for subsequent editing by the user. 5. One-dimensional bare calculation window, shown in Figure 8. "Temperature" button, used to select the temperature data for the thermal history curve. The "time" button is used to select the time data for the thermal history curve. "Exhumation Cal" button, used to perform the conversion of the thermal history curve from temperature-time curve to denudation thickness-time curve. "Ts (at sea level)" and "Elevation (m)" are the same as previously explained. "Temperature Gradient" is the geothermal gradient. "Turning Range" is the inflection point selection range of the high temperature part. "Turning Range" is used to calibrate the starting point when extending from the low temperature part to the high temperature part of the thermal history, that is, the inflection point interval between the low temperature part and the high temperature part. If it is empty, the program will search for the inflection point with the maximum angle within the entire period. If the user inputs an approximate time range, the inflection point positions of the searched low temperature part and high temperature part will be easier to approximate the actual geological situation. "Output interval": The time interval for outputting the calculation results. For example, if you enter 1, it means that one denudation thickness data will be extracted every 1 Ma, as shown in Figure 9. 6. The two-dimensional denudation and paleotopography simulation window is shown in Figure 10 . "Samples'Distance (km)" The interval at which samples are input. "Samples'Elevation (km)" The altitude at which to input the samples. "Corresponding Temperature(°C)" The paleotemperature at which the sample is input. The results of displaying the two-dimensional paleotopography simulation in the “Paleotopography” window and the results of displaying the denudation thickness simulation in the “Exhumation thickness” window are shown in Figure 11 . The listed parameters are, in order, sea surface temperature, atmospheric vertical geothermal gradient, base temperature, base depth, topographic wavelength, effective elastic thickness, Young's modulus, Poisson's ratio, mantle density, crustal density, thermal diffusion coefficient, gravitational acceleration, time node, initial search height difference value (>0), and initial search wavelength index. Custom settings for parameters can be made by referring to the program default values. All graphics and related data that appear in the main simulation window are automatically output to a directory. These graphics (Figures 12-15) are saved as PDF format files and can be re-edited in various vector editing software such as Adobe Illustrator, CorelDRAW, etc.

[0034] S7: Draw a contour map of the denudation depth of the research area according to the denudation depth at each of the field work points, and use a geological map of the research area with a standard map width of 1:50,000 or 1:200,000 as a base map to overlay the base map and the contour map of the denudation depth to obtain a denudation depth map of the research area. After obtaining the denudation depth (denudation volume) data of multiple geological points, the geological map of the 1:50,000 or 1:200,000 standard map width area was used as the base map, and MAPGIS software was used to draw the map, and an isoline map was used to show the change in denudation depth within the study area. The grid-type calculation method used was the "King universal kriging grid type", and the specific process is as follows: Data preparation: The point information and erosion volume information of the corresponding sampling points are imported into a TXT file. Discrete data gridding: Gridding work is performed using the "DTM analysis" program in the "Spatial analysis" section of the MAPGIS software. Preferably, select "Discrete data gridding" to process the above TXT document. Then, set the corresponding grid parameters (grid spacing, etc.) and select a gridding method, for example. In this simulation, the "Kring Universal Kriging gridding" method was used. Drawing plane contour lines: First, open the triangulation file and select the "Plane Contour Drawing" function. Then, set the plane contour drawing parameters, such as contour line segment parameters, smoothness degree, etc. Then, draw the plane contour line, as shown in Figure 16. Using a 1:50,000 or 1:200,000 standard width regional geological map as the base map, the following steps are taken: 1. Use the "Image Analysis" function in the "Image Processing" menu in MAPGIS to convert the 1:5W geological base map into the file type loaded by the MAPGIS software. 2. Vectorize the file, i.e., establish the corresponding point, line, and surface files. 3. Vectorize the corresponding geological map of the structural location, regional granite distribution map, etc., and merge them into a 1:5W geological vector file, as shown in Figure 17. Introduction of denudation contour maps: The established planimetric contour maps are introduced into the corresponding geological base map library file for optimization processing (e.g., whether the points are covered or not), as shown in Figure 18. Complete drawing elements: Add drawing elements such as graphic scale, compass, chart legend, map set, etc. outside the map box, add figure captions, adjust the style and color of the map, and make printing modifications to the details of the map to complete the visualization effect of the map. Figure output: Use the mapgif drawing function to output an image file.

[0035] In this example, no one has carried out the mapping work of regional geological body denudation depth with large scales such as 1:50,000 and 1:200,000 and standard base maps, nor have there been any corresponding mapping specifications, but this method systematically establishes the mapping specifications of regional geological body denudation depth of 1:50,000 / 1:200,000 through exploration and research, which is entirely original and innovative, and has many highlights and advantages. 1. Develop field line and point placement rules for denudation depth mapping (corresponding to "Step S1"). In field point placement and line placement research, we break away from the fixed numerical grid rules adopted in traditional regional geological mapping. Instead, we select field survey routes and observation research points based on the research objectives and the actual regional geology. In thermochronological research, the relevant "events" are linked and consistent within a given region, so there is no need to emphasize the constraints of survey routes and the density of field observation research points. It is important to note that point distribution occurs in different parts of the map (center, squares). The main issues to consider when mapping line and point placement for denudation depth are representativeness, followed by uniformity of point distribution, and finally point density. The field line and point placement principles determined for denudation depth mapping thus comprehensively consider the accuracy of thermochronological analysis, lithology distribution, and point uniformity when selecting points, and then set up routes according to point distribution. 2. Develop field sampling rules for denudation depth mapping (corresponding to "Step S2"). For intrusive rocks with different occurrences, establish sampling rules such as "stock-like rock body," "planar rock body," and "three-dimensional rock body." For important fault zones in the region (which penetrate the region permeably or have important structural boundaries or differences in rock age between the rocks on both sides), set control points along the fault zone at its center and both ends, and collect thermochronological samples on both sides of the fault zone at the control points. For shear zones, set three control points along the shear zone at its center and both ends (or both sides), and collect at least one thermochronological sample in each shear zone. Strive to collect highly deformed rock samples, and examine the metamorphic rocks such as old basement rocks and other altered rocks. For sedimentary strata, thermochronological research samples should be collected according to the sampling rules for intrusive rocks. For sandstone and shallow metamorphic rocks in sedimentary strata, lines and points should be significantly sparser based on the regional mapping specifications of 1:50,000 / 1:200,000 / 1:250,000. Thermochronological research samples should be collected as necessary, and continuous thermochronological cross sections should be set up: within the map width, select one or two cross sections with large elevation differences and collect thermochronological research samples according to a certain elevation difference (300 to 400 meters). Within the cross section, the sampling density can be appropriately increased at the low and high elevation ends to form a thermochronological cross section. For rocks of different lithologies, reasonable sampling volume suggestions should be provided. 3. Create field observation and recording rules (corresponding to "Step S3") applicable to thermochronological research, simplify the content of the traditional regional mapping records, and especially increase the content of sample descriptions and field photography records of sample points. 4. Formulate mineral processing rules (corresponding to "Step S4"). After collecting rock samples in the field, the next important task is to select individual minerals for use in thermochronological analysis. Due to the special characteristics of thermochronological analysis, there are special requirements for selecting individual minerals. Based on the standard process, mineral processing specifications, especially for zircon, apatite, titanite, etc., should be formulated: ensure the integrity of the crystal form as much as possible, shorten the sample crushing time, sift multiple times, and avoid crushing the sample into small pieces in one go, which will result in the crushing of large particles of zircon or apatite. Do not heat or bake at high temperatures! (The sample heating temperature must not exceed 45°C! Preferably, dry naturally.) 5. For the different thermal evolution temperature stages experienced by the rocks, thermochronological research methods corresponding to those temperature ranges are used to obtain basic data (corresponding to "Step S5"): (1) The magmatic process and the high-temperature cooling process of the rock mass (high-temperature thermal evolution processes such as magmatic crystallization, emplacement, and in situ cooling) are studied using high-temperature thermochronological methods such as zircon U-Pb isotope dating and amphibole and glassy feldspar Ar-Ar dating. (2) The rock mass uplift and denudation process are studied using medium- to low-temperature thermochronological methods, mainly biotite, muscovite, plagioclase, and low-activation energy potassium feldspar Ar-Ar dating, zircon and apatite fission tracking dating, and (U-Th) / He dating. 6. Low-T Thermo software is used to perform thermal history simulation analysis and erosion volume calculation (corresponding to "Step S6"). When conducting thermal history simulation research, software such as HeFTy and QTQt are commonly used both at home and abroad, but they have many drawbacks, such as a single function, limited scope of use, or inability to apply multi-method thermochronological data, making it difficult to directly obtain information such as erosion volume data and rock formation depth. Instead, the "Low-T Thermo" thermochronological simulation software is used. Its main functions and applications include: (1) multi-method low-temperature chronological thermal history simulation, which can use U-Th / He measurements including apatite and zircon, apatite and zircon fission tracking, mica Ar-Ar, amphibole Ar-Ar, bedrock quartz photoluminescence, vitrinite reflectance, and combinations of the above methods. There are nine different thermochronological methods used in thermal history simulation, and these nine methods can be selected arbitrarily, including single or multiple options, resulting in a theoretical total of 255 combinations. It is suitable for recovering the thermal history of orogenic belts and basins. (2) Calculating quantitative denudation volume for each period based on thermal history is applicable to studies of denudation depth and mineral deposit preservation conditions. (3) simulating paleotopography based on thermal history is applicable to paleotopography restoration studies. (4) Reverse display of thermal evolution history curves is possible, and denudation depth (denudation volume) calculation results can be directly output and displayed numerically and graphically. In the initial version, this software used the Ar-Ar thermochronology method for thermal history simulations and only applied Ar-Ar dating results for biotite. The Ar isotope closure temperature interval for biotite is 310-345°C, which is significantly different from the U-Pb closure temperature for zircon (800°C), which can easily cause distortions in the high-temperature portion of the thermal history simulation. At the same time, the Ar isotope closure temperature interval for biotite is also significantly different from the He closure temperature for zircon (200°C), which can easily cause distortions in the mid-temperature portion of the thermal history simulation. The software can be modified to include additional dating data such as potassium feldspar Ar-Ar, plagioclase Ar-Ar, and amphibole Ar-Ar as simulation parameters, further improving the accuracy of thermal history simulation in the mid- to high-temperature region and helping to obtain more accurate denudation depth values. 7. The final product map has several advantages (corresponding to "Step S7"): (1) After vectorizing the standard-width regional geological map, it is drawn as a base map, and the planimetric contour map is introduced into the corresponding geological bottom map. The two are then overlaid to create a denudation depth map. In this map, all geological elements, such as the distribution of geological bodies, structure, and lithology, are fully consistent with the regional geological map at the relevant scale. This facilitates the use of denudation depth maps for regional geological research and mineral exploration. Previous work arbitrarily adopted base maps, which were inconvenient to use and had limited application value. (2) The final map has a high point density, and the constructed denudation depth map is more accurate. (3) The map scale is large, allowing for a more detailed depiction of regional denudation history. Previous work's denudation depth maps, however, are smaller in scale and are only suitable for depicting macro-scale phenomena over a wide area, lacking application value for regional research. (4) Isolines are used to show the denudation depth, making it easy for users to quickly understand the degree of denudation and the changes in denudation depth within the study area.

[0036] In this specification, the principles and embodiments of the present invention are described by applying specific examples, and the description of the above examples is only useful for understanding the method of the present invention and its core idea, and at the same time, those skilled in the art may change the form for implementing the invention and the scope of application according to the idea of ​​the present invention. In summary, the contents of this specification should not be understood as limitations on the present invention.

Claims

1. 1. A method for large-scale mapping of denudation depth, comprising: Creating a rule for arranging field work points and work routes in the research area, and creating a rule for sampling the field work points; To establish field observation and recording rules for thermochronological research and to establish mineral processing rules; applying thermochronological research methods to measure and analyze selected target minerals at each of said field work points to obtain basic analytical data; The basic analysis data is inputted into the improved Low Thermo software to perform thermal evolution history simulation analysis and denudation depth calculation, and obtain the denudation depth at each of the field work points; and the improved Low Thermo software increases the K-feldspar Ar-Ar, plagioclase Ar-Ar and amphibole Ar-Ar dating results based on the conventional Low Thermo to be used as simulation parameters; A method comprising: drawing a contour map of denudation depth of the study area according to the denudation depth at each of the field work points; and using a geological map of a standard map width area of ​​1:50,000 or 1:200,000 of the study area as a base map, overlaying the contour map of denudation depth on the base map to obtain a denudation depth map of the study area.

2. Specifically, the establishment of the placement rules of field work points and work routes in the study area includes: Setting the field work points according to the accuracy of thermochronological analysis, the distribution characteristics of lithology, point representativeness and uniformity; The method according to claim 1, further comprising: setting the work route in accordance with a distribution of the outdoor work points.

3. Specifically, establishing field sampling rules for sampling at the field work points includes: In the case of intrusive rocks, for "rock stocks" with an exposed area of ​​less than 5 km2, one thermochronological study sample shall be collected according to the surface exposure conditions and sampling convenience conditions; In the case of a "flat rock body" in an intrusive rock, the elevation range of the exposed area is less than 400 meters. If the "flat rock body" is a convergent rock body, collect 1-2 thermochronological research samples, and the sampling positions are the center of the rock body, the highest point of the exposed rock body, the edge of the rock body, or the lowest point of the exposed rock body; if the "flat rock body" is a strip-like rock body, collect 1-3 thermochronological research samples, and the sampling positions are the center and both ends of the rock body; For the "three-dimensional rock body" in the intrusive rock, a series of thermochronological research samples are collected at an elevation difference of 300-400 meters, and the sampling density is increased at both ends of the rock body, and the elevation range within the rock body exposure range of the "three-dimensional rock body" is greater than 400 meters; In the case of a fault zone, setting control points along the fault zone at the center and both ends of the fault zone, and collecting thermochronological study samples on both sides of the fault at the control points; In the case of shear zones, establishing three control points along the shear zone, at the center and at both ends of the shear zone, and collecting at least one thermochronological study sample in each shear zone; In the case of altered strata, according to the exposure conditions of the altered strata, according to the sampling rules of the intrusive rocks, collect thermochronological study samples; For sandstones and shallow metamorphic rocks in sedimentary formations, collect lithology control samples or, depending on lithology and exposure, collect thermochronological study samples with reference to sampling rules for intrusive rocks; The method according to claim 1, characterized in that in the case of continuous thermochronological sections, the method includes selecting one or two sections with a large difference in altitude above sea level within the map width, collecting thermochronological research samples according to a predetermined altitude difference, and making them into thermochronological sections.

4. Specifically, the development of field observation and recording rules for thermochronological research includes: Dividing the field operation points into geological control points and geological observation points, and setting data description requirements for the geological control points and the geological observation points; and setting the format and content of the field logbook.

5. Specifically, establishing mineral dressing rules means: When crushing the target minerals, it is necessary to adopt non-polluting equipment and strictly prevent cross-mixing of samples; When selecting single minerals such as zircon, apatite, and titanite, it is necessary to ensure the completeness of the crystal form, complete the sample crushing within a short time, and perform multiple screenings. It is prohibited to heat and bake the sample at high temperatures, and the heating temperature of the sample must not exceed 45°C. It is necessary to select more than 1,000 grains of each single mineral. The method according to claim 1, characterized in that, when sorting silicate minerals, it is strictly prohibited to contaminate with organic matter during sorting, the grain size is required to be 60-80 mesh, the purity is required to be more than 99%, and the amount of each single mineral sorted needs to reach more than 3 grams, and said silicate minerals include amphibole, biotite, K-feldspar, plagioclase and borosilicate.

6. The application of thermochronological research methods to measure and analyze selected target minerals at each of said field work points to obtain basic analytical data includes, specifically: The method according to claim 1, characterized in that the method includes performing zircon, apatite (U-Th) / He dating analysis, apatite fission tracking dating analysis, potassium-containing silicate mineral Ar-Ar dating analysis, zircon U-Pb dating analysis, and whole-rock component analysis on the target minerals selected at the field work points to obtain the basic analysis data, and the basic analysis data includes thermochronological analysis measurement data and component analysis data of the target minerals at each of the field work points.

7. The method according to claim 1, characterized in that the basic analytical data at each of the field operation points is inputted into the improved Low Thermo software to perform thermal evolution history simulation analysis and denudation depth calculation, and obtain the denudation depth at each of the field operation points.

8. Specifically, the method includes drawing contour maps of denudation depths of the research area according to the denudation depths at each of the field work points, and using a geological map of a standard map width area of ​​1:50,000 or 1:200,000 of the research area as a base map, overlaying the base map and the contour maps of denudation depths to obtain a denudation depth map of the research area. constructing a TXT document based on point information and the denudation depth at each of the field work points; selecting "Discrete Data Grid Type" in MAPGIS software to process said TXT document; According to the processed TXT document, drawing the contour map of said denudation depth using the "plane contour drawing" function in MAPGIS software; Using the "image analysis" function in the "image processing" of MAPGIS, vectorization is performed on the geological map of the standard map width area of ​​1:50,000 or 1:200,000, and the vectorized geological map is used as the base map.

2. The method of claim 1, further comprising: applying the contour map of denudation depth to a corresponding area of ​​the base map to obtain the denudation depth map.

Images