A method for multi-generation pyrite re-os isotopic dating

Abstract

The application provides a multi-generation pyrite Re-Os isotope dating method, comprising the following steps: collecting a pyrite sample; preselecting the pyrite sample to obtain a preselected pyrite sample with a ring structure and Au distributed on the edge of the ring structure; weighing the pyrite sample and putting it into a dissolution container; adding inverse aqua into the dissolution container for step-by-step dissolution for multiple times; placing the dissolution container in ice water to reduce the dissolution rate; extracting the corresponding sample dissolution liquid in a preset interval time period in turn, and extracting at least two identical dissolution liquids each time; measuring the trace elements of the sample dissolution liquid in each preset interval time period to obtain an As / Au ratio, and calculating the ratio to obtain an Lg(As / Au) value; identifying the edge dissolution liquid of the pyrite sample according to the Lg(As / Au) value, and performing Re-Os isotope dating on the dissolution liquid. The method can realize accurate Re-Os isotope dating of the edge of the pyrite.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of isotope dating, and particularly relates to a multi-generation pyrite Re-Os isotope dating method. BACKGROUND

[0002] Pyrite is a typical product of sedimentation and hydrothermal action, and is mainly composed of iron sulfide (FeS2) and has a simple cubic crystal structure. Pyrite is closely related to gold and is the most representative mineral in gold deposits. The gold-bearing pyrite developed in gold deposits records the changes in the gold mineralization process. It is often used to limit the ore-forming age of gold deposits and trace the sources of ore-forming fluids and materials. However, due to the complex zoning structure of pyrite, it is difficult to completely eliminate by conventional methods, and pyrite itself has a heterogeneous Re content feature, which hinders the development of high-precision Re-Os isotope analysis technology of pyrite.

[0003] The first problem to be solved in high-precision pyrite Re-Os isotope analysis is the development of multi-generation structure. The current pyrite Re-Os test method research generally adopts the following steps: (ore) crushing-grinding-heavy liquid flotation-Re-Os chemical separation and mass spectrometry determination. This method has a low process blank and cross contamination risk due to the sample processing method, and the complex structure of the method cannot be separated, which limits the accuracy of subsequent isotope test work. Pyrite has multiple growth generations, and direct dating will obtain mixed age information. Due to the factors such as later alteration, exogenous, and high Re content of mixed materials, pyrite with extremely complex structure is formed, which causes the quality of dating data to decrease or show false age information, and there is a problem of inaccurate Re-Os dating of multi-generation pyrite.

[0004] In view of the above problems, it is necessary to provide a multi-generation pyrite Re-Os isotope dating method which is reasonable in design and effective in solving the above problems. SUMMARY

[0005] The application aims to at least solve one of the technical problems in the prior art, and provides a multi-generation pyrite Re-Os isotope dating method.

[0006] The application provides a multi-generation pyrite Re-Os isotope dating method, which comprises the following steps:

[0007] Step 1, collecting a pyrite sample;

[0008] Step 2, preselecting the pyrite sample to obtain a preselected pyrite sample with a zoning structure and Au distributed on the edge of the zoning structure;

[0009] Step 3: Weigh the pre-selected pyrite sample and place it in a dissolving container. Add aqua regia to the dissolving container multiple times within a preset time to gradually dissolve the sample. Place the dissolving container in ice water to reduce the dissolution rate of the pyrite sample.

[0010] Step 4: Extract the corresponding sample solution sequentially within the preset time interval, wherein at least two identical sample solutions are extracted each time.

[0011] Step 5: Measure the trace elements in the sample solutions extracted within each preset time interval to obtain the As / Au ratio, and calculate the Lg(As / Au) value using a logarithmic function on the As / Au ratio.

[0012] Step 6: Identify the pyrite sample edge dissolution solution based on the Lg(As / Au) value, and perform Re-Os isotope dating on the dissolution solution.

[0013] Optionally, in step one, a pyrite sample may be collected, including:

[0014] pyrite of pre-mineralization sedimentary or early hydrothermal origin was identified by detailed alteration-mineralization mapping in the field. Initial pyrite samples were obtained by drilling rigs.

[0015] The initial pyrite sample was finely sampled using a micro-drill sampler equipped with a synthetic diamond drill bit, and then manually purified under a binocular microscope to finally obtain a high-purity pyrite sample.

[0016] Optionally, in step two, the pyrite sample is pre-selected to obtain a pre-selected pyrite sample with a zonal structure, including:

[0017] Double-polished sample sections were prepared for the pyrite sample;

[0018] High-resolution mineralogical analysis of the sample sections was performed using an optical microscope to examine the mineral crystallography and fine structure. Pyrite from different generations was divided in detail, and samples with zonal structures were pre-selected.

[0019] Optionally, in step two, the pyrite sample is pre-selected to obtain a pre-selected pyrite sample with Au distributed at the edge of the zonal structure, including:

[0020] Laser ablation-inductively coupled plasma mass spectrometry was used to scan the mineral surface for trace elements and detect the element enrichment distribution in pyrite samples. Pre-selected pyrite samples were identified by pre-selecting Au-distributed zonal structures at the edges of the pyrite samples.

[0021] Optionally, in step three, the pre-selected pyrite sample is weighed and placed into a dissolving container. Reverse aqua regia is added to the dissolving container multiple times within a preset time to gradually dissolve the sample, including:

[0022] Weigh 0.5g to 1g of the pre-selected pyrite sample and place it in a dissolving container;

[0023] Within a preset time period, add 0.1 mL of aqua regia (3 mL HNO3 + 1.5 mL HCl) to the dissolving container in multiple portions to gradually dissolve the sample.

[0024] Optionally, in step four, the corresponding sample solutions are extracted sequentially within a preset time interval, wherein at least two identical sample solutions are extracted each time, including:

[0025] Every 5 to 20 minutes, the corresponding sample solution is extracted and transferred to the test container using a pipette. After each extraction, aqua regia is added to the remaining sample solution. Two 0.1 mL portions of sample solution are extracted simultaneously each time. One portion is used to measure trace elements, and the other portion is used for Re-Os isotope dating.

[0026] Optionally, in step six, the edge dissolution solution of the pyrite sample is identified based on the Lg(As / Au) value, including:

[0027] If the Lg(As / Au) value is greater than 3, then the current sample solution is determined to be the edge solution of the pyrite sample.

[0028] Optionally, step six involves Re-Os isotope dating of the solution, including:

[0029] If there are multiple samples with an Lg(As / Au) value > 3, the solution of the sample that first appears with an Lg(As / Au) value > 3 is selected as the edge solution of the pyrite sample.

[0030] Optionally, step six, which involves Re-Os isotope dating of the solution, also includes:

[0031] The Re-Os separation and purification of the edge solution of pyrite sample was performed to obtain a purified Re and Os solution.

[0032] The purified Re and Os solution was subjected to Re-Os isotope thermal ionization mass spectrometry to obtain Re-Os isotope data;

[0033] The Re-Os isotope data were processed to obtain the Re-Os isotope age of the edge of the pyrite sample.

[0034] Optionally, placing the dissolving container in ice water to reduce the dissolution rate of the pyrite sample includes:

[0035] Provide a cooling container, and place the melting container inside the cooling container;

[0036] Crushed ice is filled between the dissolving container and the cooling container, and pre-cooled deionized water is added to form an ice-water mixture, such that the height of the ice-water mixture is higher than the height of the sample solution in the dissolving container.

[0037] This invention discloses a Re-Os isotope dating method for multi-generation pyrite. The method involves pre-selecting pyrite samples with a zonal structure and Au distributed at the edges of the zonal structure. The pre-selected pyrite samples are then gradually dissolved, and the corresponding sample solutions are extracted sequentially at preset time intervals. Trace element measurements are performed on the extracted sample solutions at each preset time interval to obtain the As / Au ratio. The logarithmic function of the As / Au ratio is then used to calculate the Lg(As / Au) value. Based on the Lg(As / Au) value, the edge solution of the pyrite sample is identified, and Re-Os isotope dating is performed on this solution. This method can obtain edge solutions of single-gold-bearing pyrite, achieving accurate Re-Os isotope dating of pyrite edges, effectively solving the problem of inaccurate Re-Os dating of multi-generation pyrite in global gold deposits. Attached Figure Description

[0038] Figure 1 This is a schematic flowchart of a multi-generation pyrite Re-Os isotope dating method according to an embodiment of the present invention.

[0039] Figure 2 This is a backscattering image and trace element surface scan results of multigenerational gold-bearing ferrometallurgical deposits according to another embodiment of the present invention;

[0040] Figure 3 Age data for dating conventional total dissolution according to another embodiment of the present invention and age data for dating using the dating method of the present invention. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1 As shown, this invention provides a multi-generation pyrite Re-Os isotope dating method, which specifically includes:

[0043] Step 1: Collect pyrite samples.

[0044] First, pyrite of pre-mineralization sedimentary or early hydrothermal origin was identified through detailed alteration-mineralization mapping in the field. The identified pyrite was then preliminarily sampled using a drilling rig to obtain initial pyrite samples.

[0045] Specifically, in this embodiment, four types of pyrite of pre-mineralization sedimentary or early hydrothermal origin were identified through detailed alteration-mineralization mapping in the field. These pyrites developed in three stages during the main mineralization period: quartz-pyrite; quartz-pyrite and disseminated pyrite; quartz-calcite-realgar-magnetite-stibnite; and later quartz-calcite veins. This embodiment selected pyrite samples from the Yata gold mine and used a drilling rig to conduct preliminary fine sampling of the ore during the main mineralization period to obtain initial pyrite samples, avoiding the influence of other exogenous factors mixed in with the complex mineralization system.

[0046] Secondly, the initial pyrite sample was finely sampled using a micro-drill sampler equipped with a synthetic diamond drill bit, and then manually purified under a binocular microscope to finally obtain a high-purity pyrite sample.

[0047] Specifically, in this embodiment, for cases where pyrite coexists with minerals with similar physical properties such as arsenopyrite and pyrrhotite, the micro-drill can physically isolate the target mineral, avoiding the mixing of associated minerals (such as quartz, calcite, and arsenopyrite), and also avoiding changes in composition caused by chemical separation (such as acid leaching). After purification, the sample purity can reach over 99%, meeting the requirements of high-sensitivity analysis.

[0048] In this embodiment, the above-described method is used to collect pyrite samples, enabling chemical purification of multi-generational pyrite to ensure high-purity mineral extraction and to guarantee that the collected pyrite samples are simultaneous, homogeneous, and from a closed system. This step avoids contamination by sideophile and chalophile elements during the crushing-heavy liquid flotation process in traditional methods, ensuring the purity of the pyrite samples and thus guaranteeing the accuracy of Re-Os dating of pyrite.

[0049] Step 2: Pre-select the pyrite sample to obtain a pre-selected pyrite sample with a zonal structure and Au distributed at the edge of the zonal structure.

[0050] The specific process of pre-selecting pyrite samples in step two to obtain pre-selected pyrite samples with zonal structures can be described as follows:

[0051] First, double-polished sample sections were prepared for the pyrite sample.

[0052] Secondly, high-resolution mineralogical analysis of the sample sections was performed using an optical microscope to analyze the mineral crystallography and fine structure, and pyrite from different generations was divided in detail to pre-select the pyrite samples with zonal structures.

[0053] Specifically, such as Figure 2A and 2C are scanning electron microscope (SEM) images of various pyrite samples obtained using an optical microscope. Among them, [the images are from...]. Figure 2 The scanning electron microscope image in A shows that... Figure 2 The pyrite samples in group A showed poor ring structure and fewer mineral inclusions. Figure 2 As can be seen from the scanned image in C, Figure 2 The pyrite samples in C exhibit good ring structures, indicating that they are pyrite samples with complex core, mantle, and rim ring structures.

[0054] The specific process of pre-selecting pyrite samples in step two to obtain pre-selected pyrite samples with Au distributed at the edge of the zonal structure can be described as follows:

[0055] Laser ablation-inductively coupled plasma mass spectrometry was used to scan the mineral surface for trace elements and detect the element enrichment distribution in pyrite samples. Pre-selected pyrite samples with Au distribution at the edge of the zonal structure in the pyrite samples were selected.

[0056] Specifically, respectively Figure 2 A and Figure 2 Mineral surface trace element scanning was performed on each pyrite sample in C to obtain... Figure 2 B-dimensional and 2D trace element scan images. (Source: [Insert Source Here]) Figure 2 As shown in section B, trace element surface scanning reveals that the pyrite mantle has higher As and Sb contents, but lower Au and Cu contents, while the pyrite edge is rich in As (>10). 5 ppm), Au (>10) 2 ppm) and Cu. From Figure 2 As indicated by D, based on the trace element surface scan, the pyrite core has lower contents of Co, Ni, As, and Au, while the mantle is rich in As (>10). 6 ppm) but poor Au (~10 0 ppm), while pyrite edges are enriched with As (>10 ppm). 5 ppm), Au (>10) 2 ppm) and Cu. In all samples, Au-rich and As-bearing pyrite margins were overlaid with unusually As-rich but Au-poor pyrite mantle, with the As / Au ratio in the pyrite margins being approximately 10 higher than that in the pyrite mantle. 3 times.

[0057] In conclusion, choose Figure 2 Pyrite samples with better ring structures in C were selected as pre-selected pyrite samples.

[0058] Step 3: Weigh the pre-selected pyrite sample and place it in a dissolving container. Add aqua regia to the dissolving container multiple times within a preset time to gradually dissolve the sample. Place the dissolving container in ice water to reduce the dissolution rate of the pyrite sample.

[0059] The specific process of step three can be as follows:

[0060] First, weigh 0.5g to 1g of the pre-selected pyrite sample and place it into the corresponding dissolving container.

[0061] Specifically, in this embodiment, 0.5g of the seven pre-selected pyrite samples were weighed and placed into their respective beakers.

[0062] Within a preset time period, add 0.1 mL of aqua regia (3 mL HNO3 + 1.5 mL HCl) to the dissolving container in multiple portions to gradually dissolve the sample.

[0063] Specifically, every 5 to 20 minutes, add 0.1 mL of aqua regia (3 mL HNO3 + 1.5 mL HCl) to the beaker to gradually dissolve the sample.

[0064] In order to control the dissolution rate of each pre-selected pyrite sample and thus ensure complete separation of the edge and mantle of the pyrite sample, in this embodiment, each dissolution instrument is placed in ice water. Specifically, a cooling container can be provided, and the dissolution container is placed inside the cooling container; crushed ice is filled between the dissolution container and the cooling container, and pre-cooled deionized water is added to form an ice-water mixture, so that the height of the ice-water mixture is higher than the height of the sample dissolution liquid in the dissolution container, thereby reducing the dissolution rate of the pre-selected sample.

[0065] It should be noted that, in this embodiment, the specific method of controlling the dissolution rate of the pre-selected pyrite sample by using ice water is not specifically limited. It can be selected according to actual needs, as long as it can reduce the dissolution rate of the pre-selected pyrite sample.

[0066] Step 4: Extract the corresponding sample solution sequentially within the preset time interval, wherein at least two identical sample solutions are extracted each time.

[0067] The specific process of step four can be as follows:

[0068] Every 5 to 20 minutes, the corresponding sample solution is extracted and transferred to the test container using a pipette. After each extraction, aqua regia is added to the remaining sample solution. Two 0.1 mL portions of sample solution are extracted simultaneously each time. One portion is used to measure trace elements, and the other portion is used for Re-Os isotope dating.

[0069] Specifically, in this embodiment, as shown in Table 1, 0.1 mL of aqua regia is first added to the pre-selected pyrite sample. After reacting for 5 minutes, the reaction solution is extracted and transferred to the test container using a pipette. Then, 0.1 mL of aqua regia is added to the remaining sample solution, and the reaction continues for another 5 minutes. The corresponding reaction solution is then extracted and transferred to the test container using a pipette, and 0.1 mL of aqua regia is added to the remaining sample solution again to continue the reaction. This process is repeated sequentially, as shown in Table 1, with the sample solutions after 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 40 minutes, and 60 minutes of reaction time extracted and transferred to the test container using a pipette.

[0070] In this embodiment, aqua regia is added to the dissolving container multiple times within a preset time period to gradually dissolve the sample. The corresponding sample solutions are then extracted sequentially at preset intervals to obtain the gradually dissolved pyrite sample solution. This allows for the separation of the pyrite sample's edge from its mantle portion, yielding a single pyrite-bearing edge solution, thus enabling precise Re-Os isotopic dating of the pyrite edge.

[0071] Table 1. As and Au contents, As / Au ratio, and Lg(As / Au) values ​​of pyrite samples at different time periods.

[0072]

[0073] Step 5: Measure the trace elements in the extracted sample solutions within each preset time interval to obtain the As / Au ratio, and calculate the Lg(As / Au) value using a logarithmic function on the As / Au ratio.

[0074] Specifically, trace element measurements were performed on the sample solutions extracted during the aforementioned time periods to obtain the As and Au values ​​and the As / Au ratio as shown in Table 1. The Lg(As / Au) value was then calculated using a logarithmic function on the As / Au ratio.

[0075] As shown in Table 1, the As / Au ratio of the sample solution evolved as follows, according to the test data: the ratio decreased from 5 minutes to 10 minutes, then briefly rebounded at 10-15 minutes, and finally stabilized after 20-30 minutes. For each sample YT1, at 5 minutes, the As / Au ratio of the sample solution was 3323, with a corresponding Lg(As / Au) value of 3.52. At 10 minutes, the As / Au ratio of the sample solution was 2039, with a corresponding Lg(As / Au) value of 3.31. The sample solution at 5–10 minutes indicates dissolution of the pyrite edge, and the abnormally high As / Au ratio can be attributed to the initial preferential dissolution of arsenic relative to gold. At 20 minutes, the As / Au ratio was 868, with a corresponding Lg(As / Au) value of 2.94, indicating that the arsenic-rich and gold-poor pyrite mantle began to dissolve. These pyrite mantles have a higher As / Au ratio than the arsenic-rich and gold-rich edges. From 30–60 minutes, the As / Au ratio tended to remain constant, with As / Au ratios of 82–41 and corresponding Lg(As / Au) values ​​of 1.61–1.91, indicating dissolution to the pyrite sample mantle.

[0076] Step 6: Identify the pyrite sample edge dissolution solution based on the Lg(As / Au) value, and perform Re-Os isotope dating on the dissolution solution.

[0077] In step six, the specific process of identifying the edge dissolution solution of the pyrite sample based on the Lg(As / Au) value can be described as follows:

[0078] If the Lg(As / Au) value is greater than 3, the current sample dissolution solution is determined to be the edge dissolution solution of the pyrite sample. Specifically, as shown in Table 1, the sample dissolution solutions after 5 minutes and 10 minutes can both be determined to be the edge dissolution solutions of the pyrite sample.

[0079] Preferably, if there are multiple samples with an Lg(As / Au) value > 3, the sample solution from the first sample with an Lg(As / Au) value > 3 is selected as the edge solution for the pyrite sample. That is, in this embodiment, the sample solution extracted for 5 minutes is selected as the edge solution for the pyrite sample. This ensures a purer edge solution for the pyrite sample, thus guaranteeing the accuracy of Re-Os isotope dating of the pyrite edge. Subsequently, the Re-Os age of the extracted 5-minute pyrite solution can represent the formation age of the gold-bearing pyrite edge, i.e., the gold precipitation age.

[0080] The specific process of Re-Os isotope dating of the solution in step six can be as follows:

[0081] First, the Re-Os separation and purification of the pyrite sample edge solution was performed to obtain a purified Re and Os solution.

[0082] Secondly, the purified Re and Os solutions were subjected to Re-Os isotope thermal ionization mass spectrometry to obtain Re-Os isotope data;

[0083] The Re-Os isotope data were processed again to obtain the Re-Os isotope age of the edge of the pyrite sample.

[0084] Specifically, such as Figure 3 As shown in Figure A, the pyrite age obtained using traditional methods is ~253 Ma, older than the host rock age (239 Ma), indicating that traditional methods are difficult to obtain accurate ages of multi-generation pyrite. Figure 3 As shown in Figure B, the edge age of pyrite obtained by the multi-generation pyrite Re-Os isotope dating method of the present invention is ~183 Ma, which is consistent with geological facts, indicating that the multi-generation pyrite Re-Os isotope dating method of the present invention can obtain a high-precision mineralization age.

[0085] In this embodiment, the Lg(As / Au) value is creatively proposed as an indicator for identifying the edge of a pyrite sample. This allows for the rapid separation of the dissolved liquid from the edge of the pyrite sample, thereby achieving high-precision Re-Os isotope dating of the pyrite edge and obtaining a high-precision mineralization age.

[0086] This invention discloses a Re-Os isotope dating method for multi-generation pyrite. The method involves pre-selecting pyrite samples with a zonal structure and Au distributed at the edges of the zonal structure. The pre-selected pyrite samples are then gradually dissolved, and the corresponding sample solutions are extracted sequentially at preset time intervals. Trace element measurements are performed on the extracted sample solutions at each preset time interval to obtain the As / Au ratio. The logarithmic function of the As / Au ratio is then used to calculate the Lg(As / Au) value. Based on the Lg(As / Au) value, the edge solution of the pyrite sample is identified, and Re-Os isotope dating is performed on this solution. This method can obtain edge solutions of single-gold-bearing pyrite, achieving accurate Re-Os isotope dating of pyrite edges, effectively solving the problem of inaccurate Re-Os dating of multi-generation pyrite in global gold deposits.

[0087] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A multi-generation pyrite Re-Os isotope dating method, characterized in that, The method includes: Step 1: Collect pyrite samples; Step 2: Pre-select the pyrite sample to obtain a pre-selected pyrite sample with a zonal structure and Au distributed at the edge of the zonal structure; Step 3: Weigh the pre-selected pyrite sample and place it in a dissolving container. Add aqua regia to the dissolving container multiple times within a preset time to gradually dissolve the sample. Place the dissolving container in ice water to reduce the dissolution rate of the pyrite sample. Step 4: Extract the corresponding sample solution sequentially within the preset time interval, wherein at least two identical sample solutions are extracted each time. Step 5: Measure the trace elements in the sample solutions extracted within each preset time interval to obtain the As / Au ratio, and calculate the Lg(As / Au) value using a logarithmic function on the As / Au ratio. Step 6: Identify the edge dissolution of the pyrite sample based on the Lg(As / Au) value, and perform Re-Os isotope dating on the dissolution; if the Lg(As / Au) value is >3, the current sample dissolution is determined to be the edge dissolution of the pyrite sample.

2. The method according to claim 1, characterized in that, Step one involves collecting pyrite samples, including: pyrite of pre-mineralization sedimentary or early hydrothermal origin was identified by detailed alteration-mineralization mapping in the field. Initial pyrite samples were obtained by drilling rigs. The initial pyrite sample was finely sampled using a micro-drill sampler equipped with a synthetic diamond drill bit, and then manually purified under a binocular microscope to finally obtain a high-purity pyrite sample.

3. The method according to claim 1, characterized in that, Step two involves pre-selecting the pyrite sample to obtain a pre-selected pyrite sample with a zonal structure, including: Double-polished sample sections were prepared for the pyrite sample; High-resolution mineralogical analysis of the sample sections was performed using an optical microscope to examine the mineral crystallography and fine structure. Pyrite from different generations was divided in detail, and samples with zonal structures were pre-selected.

4. The method according to any one of claims 1 to 3, characterized in that, Step two involves pre-selecting the pyrite sample to obtain a pre-selected pyrite sample with Au distributed at the edge of the zonal structure, including: Laser ablation-inductively coupled plasma mass spectrometry was used to scan the mineral surface for trace elements and detect the element enrichment distribution in pyrite samples. Pre-selected pyrite samples were identified by pre-selecting Au-distributed zonal structures at the edges of the pyrite samples.

5. The method according to any one of claims 1 to 3, characterized in that, In step three, the pre-selected pyrite sample is weighed and placed into a dissolving container. Reverse aqua regia is added to the dissolving container multiple times within a preset time to gradually dissolve the sample, including: Weigh 0.5 g to 1 g of the pre-selected pyrite sample and place it in a dissolving container; Within a preset time period, 0.1 mL of aqua regia was added to the dissolving container in multiple portions to gradually dissolve the sample. The aqua regia consisted of 3 mL of HNO3 and 1.5 mL of HCl.

6. The method according to claim 5, characterized in that, In step four, the corresponding sample solutions are extracted sequentially within a preset time interval. Each extraction involves extracting at least two identical sample solutions, including: Every 5 to 20 minutes, the corresponding sample solution is extracted and transferred to the test container using a pipette. After each extraction, aqua regia is added to the remaining sample solution. Two 0.1 mL samples are extracted at the same time each time. One sample solution is used to measure trace elements, and the other sample solution is used for Re-Os isotope dating.

7. The method according to any one of claims 1 to 3, characterized in that, Step six involves Re-Os isotope dating of the solution, including: If there are multiple samples with an Lg(As / Au) value > 3, the solution of the sample that first appears with an Lg(As / Au) value > 3 is selected as the edge solution of the pyrite sample.

8. The method according to any one of claims 1 to 3, characterized in that, Step six, which involves Re-Os isotope dating of the solution, also includes: The Re-Os separation and purification of the edge solution of pyrite sample was performed to obtain a purified Re and Os solution. The purified Re and Os solution was subjected to Re-Os isotope thermal ionization mass spectrometry to obtain Re-Os isotope data; The Re-Os isotope data were processed to obtain the Re-Os isotope age of the edge of the pyrite sample.

9. The method according to any one of claims 1 to 3, characterized in that, The step of placing the dissolving container in ice water to reduce the dissolution rate of the pyrite sample includes: Provide a cooling container, and place the melting container inside the cooling container; Crushed ice is filled between the dissolving container and the cooling container, and pre-cooled deionized water is added to form an ice-water mixture, such that the height of the ice-water mixture is higher than the height of the sample solution in the dissolving container.

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