A method for evaluating the mineralization potential of porphyry copper-(gold-molybdenum) deposits

Abstract

The application discloses a method for evaluating the mineralization potential of porphyry copper-(gold-molybdenum) ore. The evaluation method comprises the following steps: determining a candidate rock mass with higher mineralization potential according to the oxygen fugacity value of the magmatic zircon and / or the magmatic water content value of the hornblende in the rock sample of the evaluation area; calculating the aluminum saturation index (ASI) of the candidate rock mass, determining the distribution coefficient and the distribution coefficient ratio of Cu, Au and Mo between the fluid-melt according to the ASI, and simulating and calculating according to the distribution coefficient and / or the distribution coefficient ratio through the Rayleigh fractionation model to obtain the content ratio of Au, Cu and Mo in the candidate ore body. The application can quickly and accurately evaluate the mineralization potential of the porphyry copper ore and the enrichment degree and grade of Cu, Au and Mo in the potential ore body.

Description

Technical Field

[0001] This invention relates to the field of metal mineral exploration technology, and in particular to a method for assessing the mineralization potential of porphyry copper-(gold-molybdenum) deposits. Background Technology

[0002] Porphyry copper deposits (especially those rich in Au and Mo) are important sources of metallic minerals globally. Their mineralization process is typically related to the evolution of acidic intrusive bodies in arc environments and the release of hydrothermal fluids. Metallic copper, along with associated gold (Au) and molybdenum (Mo), migrates from magma into the fluids and is enriched into minerals in the shallow crust through hydrothermal activity. However, not all arc magmatic systems possess mineralization potential; the vast majority of arc magmas are low-ore-bearing or show only weak mineralization. Therefore, in actual mineral exploration, a rapid screening process based on certain conditions should be conducted first, focusing on exploration targets with mineralization potential to improve exploration efficiency.

[0003] Porphyry copper-bearing magmas typically exhibit high oxygen fugacity and water abundance. Under these conditions, sulfides in the magma become unstable, and their decomposition leads to the enrichment of ore-forming elements in the exsolution fluids. Therefore, magmatic systems with high oxygen fugacity and water abundance are considered prerequisites for mineralization potential and should be given priority in porphyry copper deposit exploration.

[0004] Currently, traditional methods for evaluating porphyry copper deposits include regional geological surveys, rock geochemical analysis, geophysical exploration, and remote sensing prospecting. These methods are typically time-consuming, inefficient, and costly, making it difficult to effectively and quickly assess the mineralization potential of magmatic systems. Therefore, developing a more efficient method for evaluating the mineralization potential of porphyry copper deposits to narrow down the actual exploration area is of great significance for saving time, reducing economic costs, and improving exploration efficiency. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to propose an assessment method that can quickly and accurately evaluate the mineralization potential of porphyry copper-(gold-molybdenum) deposits. This method can also accurately assess the enrichment degree and grade of Cu and its associated metals Au and Mo in porphyry copper-(gold-molybdenum) deposits with mineralization potential.

[0006] The technical solution of the present invention is as follows:

[0007] A method for assessing the mineralization potential of porphyry copper-(gold-molybdenum) deposits, comprising:

[0008] (1) Sample fresh, unaltered rock masses in the area to be assessed to obtain rock samples;

[0009] (2) Magmatic zircons were screened from the rock samples, and the oxygen fugacity values ​​of the magmatic zircons and the corresponding average oxygen fugacity values ​​of the sampled rock masses were calculated. With average oxygen fugacity value The sampled rock bodies corresponding to magmatic zircons with an oxygen fugacity offset ΔFMQ greater than +1 relative to the FMQ buffer pair are candidate rock bodies with high mineralization potential.

[0010] (3) Amphibole is screened from the rock samples, and the magma water content of the amphibole is calculated. The sampled rock body with a magma water content of more than 5% is the candidate rock body with high mineralization potential.

[0011] (4) Sample the candidate rock mass. Select fresh rocks that have not undergone significant alteration to obtain a sample. Calculate the aluminum saturation index of the sample. Determine the partition coefficients of Cu, Au, and Mo in the fluid-melt and / or the partition coefficient ratio of Cu and Au, the partition coefficient ratio of Cu and Mo, and the partition coefficient ratio of Au and Mo in the candidate rock mass based on the aluminum saturation index.

[0012] (5) Based on the obtained allocation coefficients and / or allocation coefficient ratios, simulation calculations are performed to obtain the content ratios of Au, Cu and Mo, Cu in the candidate ore body, and the mineralization potential of the candidate ore body is evaluated based on the obtained content ratios; the simulation calculations use the Rayleigh fractionation model.

[0013] The above technical solutions of the present invention fully consider that the rebalancing process of elements in zircon through chemical diffusion under magmatic temperature conditions is extremely slow, and its chemical composition is highly sensitive to the redox state of the magmatic system. Therefore, magmatic zircon can serve as an ideal tracer mineral for recording magmatic evolution and changes in its physicochemical properties. During the ascent of magma, the crystallization of silicate minerals leads to the gradual saturation of water in the magma. This process is crucial for the extraction of ore-forming metals from the magma, so water-rich magma is also key to mineralization. Based on this, calculating the whole-rock aluminum saturation index of magma is an important step that can fully assess the physicochemical properties of magma and its mineralization potential. The inventors unexpectedly discovered that the aluminum saturation index has a significant impact on the Au / Cu and Mo / Cu content ratios in the exsolution fluids of magma. Therefore, the Au / Cu and Mo / Cu content ratios of potential ore bodies in different ASI magmatic systems can be predicted based on experimental and simulation calculation results.

[0014] In the above technical solutions of the present invention, the relationship between the aluminum saturation index and the partition coefficients and / or the ratio of the partition coefficients of Cu, Au, and Mo between the fluid and the melt, and the partition coefficient ratio of Cu and Mo and the partition coefficient ratio of Au and Mo, can be obtained by conducting high-temperature and high-pressure experiments in the laboratory to simulate the partitioning process of metal elements between magma and fluid, and by systematically analyzing and detecting the products after the experiment to obtain the functional relationship between the magma aluminum saturation index and the partition coefficients and / or the partition coefficient ratios.

[0015] According to some preferred embodiments of the present invention, the average oxygen fugacity value of the sampled rock mass The calculations include:

[0016] Multiple rock samples were collected from each type of rock mass, and magmatic zircon was screened for each. The screened magmatic zircons were then prepared into samples, with clean areas free of fractures and inclusions used as the analysis areas. Trace element analysis was performed at multiple analysis points using laser ablation inductively coupled plasma mass spectrometry (ICP-MS) at a spot size of 60-120 μm. The oxygen fugacity value of the magmatic zircon at any given analysis point was calculated based on the obtained trace element composition. The average oxygen fugacity value at all analysis points is taken as the average oxygen fugacity value of the sampled rock mass.

[0017] According to some preferred embodiments of the present invention, the oxygen fugacity value of the magmatic zircon The following calculation model is used:

[0018]

[0019] in, Let represent the oxygen fugacity value at the nth analysis point, Ce represent the cerium content in the magmatic zircon at that analysis point, U represent the uranium content in the magmatic zircon at that analysis point, and Ti represent the titanium content in the magmatic zircon at that analysis point.

[0020] According to some preferred embodiments of the present invention, the average oxygen fugacity value of the rock mass The following calculation model is used:

[0021]

[0022] in, This represents the oxygen fugacity value at the nth analysis point.

[0023] According to some preferred embodiments of the present invention, the calculation of the magma water content includes: analyzing the content of major element oxides and trace elements in the amphibole by electron probe microanalysis, wherein the major element oxides include Na2O, K2O, CaO, MgO, FeO, Al2O3, and SiO2, and the trace elements include Cl and F; and calculating the magma water content using the Amp-TB2 model based on the analysis results.

[0024] According to some preferred embodiments of the present invention, in the analysis of the content of major element oxides and trace elements, the analysis conditions for major element oxides are 15kV accelerating voltage, 5nA beam current and 5μm beam spot diameter, wherein the content measurement of Na2O and K2O uses a peak counting time of 10s and a background counting time of 5s, and the content measurement of other major element oxides uses a peak counting time of 20s and a background counting time of 10s; the analysis conditions for trace elements are 15kV accelerating voltage, 20nA beam current and 15μm beam spot diameter, and the counting times are a peak of 120s and a background of 60s.

[0025] Preferably, in trace element content analysis, glass standard samples, which are known samples, are measured periodically to control the long-term relative accuracy to 2%.

[0026] According to some preferred embodiments of the present invention, the calculation of the aluminum saturation index includes: performing X-ray fluorescence spectrometry and / or inductively coupled plasma atomic emission spectrometry analysis on the sampled sample to obtain its whole-rock chemical composition content and the contents of Al2O3, Na2O, K2O and CaO; and obtaining the aluminum saturation index (ASI) using the following formula:

[0027] ASI=nAl2O3 / (nNa2O+nK2O+nCaO)

[0028] Wherein, nAl2O3, nNa2O, nK2O and nCaO are the molar percentages of Al2O3, Na2O, K2O and CaO, respectively.

[0029] According to some preferred embodiments of the present invention, the simulation calculation includes:

[0030] The concentrations of Cu, Au, and Mo in the initial melt were set to be consistent with the average concentrations of these metals in typical arc magmas and magmas that generate porphyry Cu-(Mo±Au) deposits.

[0031] The melt is set to undergo fluid exsolution at the beginning of water saturation, and the Cl content of the magma and the first exsolution fluid is set to be consistent with the Cl content range in typical arc magma and the chloride content range of fluid inclusions at the root of porphyry copper deposits.

[0032] Assuming that Cl and water are 100% incompatible with anhydrous crystalline minerals, the magma-mineral partition coefficients of Cu, Au, and Mo are determined based on experimental measurements.

[0033] The melt is set to reach water saturation at a water content of 6 wt.%, corresponding to a confining pressure of 200 MPa.

[0034] The initial water content in the magma is set to the magma water content of the amphibole calculated in step (3);

[0035] Based on the above settings, the differentiation process of fluid in an open magma chamber is simulated using the Rayleigh fractionation model. Each step is defined as 1 wt.% of magma crystallization. The concentration of metal M in the magma fluid under different magma crystallinity is obtained, where M represents any one of Cu, Au, and Mo.

[0036] More preferably, the concentrations of Cu, Au, and Mo in the initial melt are set to 50 ppm, 2 ppb, and 2 ppm, respectively.

[0037] More preferably, the concentration of Cl in the magma at the beginning of water saturation, i.e., after magma crystallization of 1 wt.%, is set to 2000, 2300, and 2500 ppm, and the chloride content of the first batch of exudate is set to 1, 2, and 4 mol / kg H2O.

[0038] More preferably, the magma-mineral partition coefficients of Cu, Au and Mo are set to 0.2, 0.1 and 0.2, respectively.

[0039] More preferably, the concentration of metal M in magma fluids under different magma crystallinity is obtained through the following calculation model:

[0040]

[0041] in Let F be the concentration of metal M in the fluid when the magma has a crystallinity of F. Let M be the initial concentration of metal M in the magma, F be the degree of crystallization of the magma, and D be the initial concentration of metal M in the magma. M Let M be the distribution coefficient of metal M.

[0042] Furthermore, based on the above calculation results, the mass of metal M extracted by the fluid when the magma crystallinity is F and the ratio of the masses of different metals M can be obtained by integration, that is, the potential Cu, Au and Mo grades and enrichment degree of the ore body can be obtained.

[0043] The present invention has the following beneficial effects:

[0044] This invention can combine magma oxygen fugacity, magma water content, magma aluminum saturation index (ASI), metal distribution curves, and numerical simulation calculations to construct a comprehensive mineralization potential evaluation model; it can quickly identify the mineralization potential in different magma systems, accurately determine the enrichment characteristics of copper, gold, and molybdenum, and select appropriate exploration methods according to the characteristics of different deposit types.

[0045] This invention can assess the mineralization potential of porphyry copper deposit systems in a relatively short time, greatly improving exploration efficiency.

[0046] This invention is applicable not only to copper deposits but also to the evaluation of gold and molybdenum deposits. It can provide technical guidance for different types of porphyry copper mining areas, and is highly adaptable and widely applicable.

[0047] Compared with traditional geological exploration methods, this invention has significant cost advantages, can greatly reduce the time and cost of on-site exploration, and improve the economic benefits of mineral resource exploration. Attached Figure Description

[0048] Figure 1 This is a graph showing the relationship between the Cu-Au-Mo partition coefficient and the magma ASI in Example 3.

[0049] Figure 2 This is a graph showing the relationship between the Cu-Au-Mo partition coefficient ratio and the magma ASI in Example 3.

[0050] Figure 3 The diagram shows the range of Au / Cu and Mo / Cu ratios within porphyry copper deposits formed by different ASI magmas in Example 3. The initial H2O content of the magma was set to 2 and 6 wt%, respectively. Detailed Implementation

[0051] The technical solutions of the present invention will be further described below with reference to embodiments thereof. The embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0052] Example 1

[0053] The following steps are used to assess the mineralization potential of porphyry copper deposits based on oxygen fugacity values:

[0054] (1) Through field observation, select representative, fresh, and unaltered intrusive rock bodies in the exploration area for sample collection. Collect 5-10 samples from each rock body. Crush the collected samples and screen out the magmatic zircons. Select about 10 magmatic zircons from each rock body. Avoid magmatic zircons with inclusions or weathering during the screening process to ensure the accuracy of the analysis results.

[0055] (2) The selected magmatic zircons were fixed on an epoxy resin target and polished. Observation was performed under a microscope and cathodoluminescence (CL). Clean areas without cracks or inclusions were selected as the analysis area. Trace element analysis was performed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) at a spot size of 60-120 μm. Based on the obtained trace element composition, the oxygen fugacity value of the magmatic zircons and the average oxygen fugacity value of the magma were calculated.

[0056] (3) Screening out the average oxygen fugacity value Rock masses with an offset ΔFMQ greater than +1 relative to the FMQ buffer for oxygen fugacity (hereinafter referred to as FMQ) are considered as candidate rock masses with high mineralization potential.

[0057] Among them, the oxygen fugacity value of zircon at any analysis point n The calculation method is as follows:

[0058]

[0059] Where Ce represents the cerium content in magmatic zircon, U represents the uranium content in magmatic zircon, and Ti represents the titanium content in magmatic zircon.

[0060] Mean oxygen fugacity value of magma The following calculation model is used:

[0061]

[0062] This embodiment, based on the above steps, statistically analyzed the ore-generating magmas of a certain andesite in the Pliocene-Pleistocene arc magma of the western Pacific and the Cu-(Au±Mo) deposits in the eastern-western Pacific arc, including the Grasberg, Ok Tedi, and ElTeniente deposits. The values ​​are FMQ-0.8 to FMQ+0.4 (i.e., ΔFMQ = -0.8 to +0.4), and FMQ+0.9 to FMQ+1.7 (i.e., ΔFMQ = +0.9 to +1.7), FMQ+0.4 to FMQ+1.7 (i.e., ΔFMQ = +0.4 to +1.7), and FMQ+1.4 to FMQ+2.2 (i.e., ΔFMQ = +1.4 to +2.2). The calculation results are consistent with the actual geological conditions, that is, the andesite in this area does not contain porphyry copper deposits, while the magmatic rocks in the Grasberg, Ok Tedi, and El Teniente areas all contain large porphyry copper deposits.

[0063] Example 2

[0064] The following steps are used to assess the mineralization potential of porphyry copper deposits based on magma water content:

[0065] (1) Fresh amphibole samples that have not undergone alteration and show no obvious signs of metamorphism were selected from the samples collected in Example 1;

[0066] (2) The content of major element oxides and trace elements in the amphibole sample was analyzed by electron probe microanalysis. The major element oxides included Na2O, K2O, CaO, MgO, FeO, Al2O3, and SiO2, and the trace elements included Cl and F. The analytical conditions for the major element oxides were 15kV accelerating voltage, 5nA beam current, and 5μm beam spot diameter. The content of Na2O and K2O was measured using a peak counting time of 10s and a background counting time of 5s to minimize the loss of these elements during the analysis. The other major element oxides were analyzed using a peak counting time of 20s and a background counting time of 10s. The detection conditions for trace elements Cl and F were 15kV accelerating voltage, 20nA beam current, and 15μm beam spot diameter, with a peak counting time of 120s and a background counting time of 60s, respectively. When detecting the content of Cl and F, glass standard samples, which were known samples, were measured periodically to control the long-term relative accuracy to 2%.

[0067] (3) Based on the analysis results, the magma water content is calculated using the Amp-TB2 model. If the water content exceeds 5%, the magma is considered to have mineralization potential, and the corresponding rock body is a candidate rock body with high mineralization potential.

[0068] Example 3

[0069] The following steps were used to assess the mineralization potential of porphyry copper deposits and evaluate the grades of Cu and associated metals Mo and Cu:

[0070] (1) Samples were taken from the candidate rock masses selected in Examples 1 and 2. The samples were fresh rocks that had not undergone significant alteration.

[0071] (2) Crush about 20g of rock sample into small particles, grind them into fine powder using a ball mill or vibratory mill, control the particle size to below 200 mesh, and dry them in an oven at 110℃ to remove moisture and obtain dry sample powder.

[0072] (3) Add the dry sample powder to a covered Teflon beaker, add hydrofluoric acid and nitric acid in sequence, and heat until the sample is completely dissolved to obtain a sample solution;

[0073] (4) The sample solution is purified by ion exchange to obtain a purified sample solution;

[0074] (5) Elemental analysis of the purified sample solution was performed by ICP-OES (inductively coupled plasma optical emission spectrometry) to determine the contents of Al2O3, Na2O, K2O and CaO.

[0075] (6) Based on the measurement results, the whole-rock aluminum saturation index (ASI) of the sample was calculated as follows:

[0076] ASI=nAl2O3 / (nNa2O+nK2O+nCaO)

[0077] Where nAl2O3, nNa2O, nK2O and nCaO are the molar percentages of the corresponding oxides;

[0078] (7) Based on the calculated ASI value, through the attached... Figure 1 The relationship between Cu-Au-Mo partition coefficients and magma ASI shown in the diagram determines the partition coefficients of Cu, Au, and Mo in the fluid-melt relationship of the ore body in the candidate rock mass corresponding to the sample. (See attached diagram.) Figure 2 The graph showing the relationship between the Cu-Au-Mo partition coefficient ratio and the magma ASI indicates the Cu-Au partition coefficient ratio D of the ore body in the candidate rock mass corresponding to the sample. Cu / D Au The partition coefficients of Cu and Mo are higher than those of D. Cu / D Mo and the ratio of the partition coefficients of Au and Mo to D Au / D Mo ;

[0079] (8) Based on the obtained distribution coefficient ratios, simulation calculations are performed to obtain the Au / Cu and Mo / Cu content ratios of the candidate ore bodies, and the mineralization potential of the candidate ore bodies is evaluated based on the obtained content ratios; wherein, the simulation calculation adopts the Rayleigh fractionation model, and the simulation calculation process includes:

[0080] The initial concentrations of Cu, Au, and Mo in the melt were set to 50 ppm, 2 ppb, and 2 ppm, respectively, which are similar to the average contents of these metals in typical arc magmas and magmas that generate porphyry Cu-(Mo±Au) deposits.

[0081] The Cl element concentrations of the melt at the start of H2O saturation, i.e., after 1 wt.% magma crystallization, were set to 2000, 2300, and 2500 ppm, respectively, and the chloride concentrations of the first distribution fraction of the differentiating fluid were 1, 2, and 4 mol / kg H2O, respectively, covering the range of Cl element concentrations in typical arc magmas and the range of chloride concentrations in the root differentiating fluids of porphyry copper deposit systems.

[0082] To simplify the model, Cl and H2O are assumed to be 100% incompatible with anhydrous crystalline minerals.

[0083] Based on the fact that Cu, Au, and Mo are mostly incompatible with the main silicate minerals, including plagioclase, pyroxene, amphibole, and a small amount of magnetite, during magma crystallization, the magma / mineral partition coefficients of Cu, Au, and Mo are set to 0.2, 0.1, and 0.2, respectively, according to experimental measurements.

[0084] The melt was set to reach H2O saturation at an H2O content of 6 wt.%, corresponding to a confining pressure of 200 MPa. The initial H2O content in the magma was set according to the calculation results of Example 2.

[0085] Based on the above settings, the differentiation process of fluid in an open magma chamber was simulated using the Rayleigh fractionation model, with each step representing 1 wt.% of crystallization. The specific computational model was then used. By obtaining the metal concentration in magmatic fluids at different degrees of crystallization, the following results can be obtained: Figure 3 The graph shows the relationship between the metal content ratio of potential magma-formed ore bodies with different ASI values ​​and ASI, thereby determining the metal content ratio and mineralization potential of candidate rock bodies based on their ASI.

[0086] Example 4

[0087] The mineralization potential of the Grasberg Cu-Au and El Teniente Cu-Mo deposits was evaluated according to the process in Example 3. The whole-rock aluminum saturation indices for both deposits were measured to be 1.1 and 1.3, respectively. Simulation results showed that the average Au / Cu and Mo / Cu ratios of the ore bodies were ~0.8-0.9×10⁻⁴ and ~0.015, respectively, which are very close to the measured Au / Cu and Mo / Cu ratios (~0.9-1.2×10⁻⁴ and ~0.026, respectively) of the Grasberg Cu-Au and El Teniente Cu-Mo deposits, indicating that the evaluation method of this invention is accurate and effective.

[0088] It should be noted that the above descriptions are merely preferred embodiments of the present invention and should not limit the scope of protection of the technical solutions of the present invention. Any modifications made to the technical solutions described in the foregoing embodiments, or equivalent substitutions of technical features, by those skilled in the art within the spirit and principles of the present invention, should be included within the scope of protection of the present invention.

Claims

1. A method for assessing the mineralization potential of porphyry copper-(gold-molybdenum) deposits, characterized in that, It includes: (1) Sample fresh, unaltered rock masses in the area to be assessed to obtain rock samples; (2) Magmatic zircons were screened from the rock samples, and the oxygen fugacity value of the magmatic zircons and the average oxygen fugacity value of the corresponding sampled rock mass were calculated. f O2 With average oxygen fugacity value f O2 The sampled rock bodies corresponding to magmatic zircons with an oxygen fugacity offset ∆FMQ greater than +1 relative to the FMQ buffer pair are candidate rock bodies with high mineralization potential. (3) Select amphibole from the rock samples, calculate the magma water content of the amphibole, and select the sampled rock body with a magma water content of more than 5% as the candidate rock body with high mineralization potential. (4) Sample the candidate rock mass. Select fresh rocks that have not undergone significant alteration to obtain a sample. Calculate the aluminum saturation index of the sample. Determine the partition coefficients of Cu, Au, and Mo in the fluid-melt and / or the partition coefficient ratio of Cu and Au, the partition coefficient ratio of Cu and Mo, and the partition coefficient ratio of Au and Mo in the candidate rock mass based on the aluminum saturation index. (5) Based on the obtained distribution coefficients and / or distribution coefficient ratios, simulation calculations are performed to obtain the content ratios of Au, Cu and Mo, Cu in the candidate rock mass, and the mineralization potential of the candidate rock mass is evaluated based on the obtained content ratios; the simulation calculations use the Rayleigh fractionation model; The simulation calculation includes: The concentrations of Cu, Au, and Mo in the initial melt were set to be consistent with the average concentrations of these metals in typical arc magmas and magmas that generate porphyry Cu-(Mo±Au) deposits. The melt is set to undergo fluid exsolution at the beginning of water saturation, and the Cl content of the magma and the first exsolution fluid is set to be consistent with the Cl content range in typical arc magma and the chloride content range of fluid inclusions at the root of porphyry copper deposits. We set Cl and water to be 100% incompatible with anhydrous crystalline minerals, and based on experimental measurements, we set the magma-mineral partition coefficients for Cu, Au, and Mo. The melt is set to reach water saturation at a water content of 6wt%, corresponding to a confining pressure of 200MPa. The initial water content in the magma is set to the magma water content of the amphibole calculated in step (3); Based on the above settings, the differentiation process of fluid in an open magma chamber is simulated using the Rayleigh fractionation model. Each step is defined as 1 wt% of magma crystallization. The concentration of metal M in the magma fluid under different magma crystallinity is obtained, where M represents any one of Cu, Au, and Mo. The concentration of metal M in the magma fluid under different magma crystallinity conditions is obtained through the following calculation model: Cfluid p= [Cmelt 0*(1-F) / F]*(D M ) Where Cfluid p is the concentration of metal M in the fluid when the magma crystallinity is F, Cmelt 0 is the initial concentration of metal M in the magma, F is the degree of magma crystallinity, and D... M Let M be the distribution coefficient of metal M.

2. The evaluation method according to claim 1, characterized in that, The average oxygen fugacity value of the sampled rock mass f O2 The calculations include: Multiple rock samples were collected from each type of rock mass, and magmatic zircon was screened for each. The screened magmatic zircons were then prepared into samples, with clean areas free of fractures and inclusions used as the analysis regions. Trace element analysis was performed at multiple analysis points using laser ablation inductively coupled plasma mass spectrometry (ICP-MS) at a spot size of 60–120 μm. The oxygen fugacity value of the magmatic zircon at any given analysis point was calculated based on the obtained trace element composition. f O2n The average oxygen fugacity value of the sampled rock mass is taken as the average oxygen fugacity value at all analysis points. f O2 .

3. The evaluation method according to claim 2, characterized in that, in, The oxygen fugacity value of the magmatic zircon f O2n The following calculation model is used: f O2 n=3.998×log 10 (Ce / [(U*Ti) 0.5 ])+2.284 in, f O2 n represents the oxygen fugacity value at the nth analysis point, Ce represents the cerium content in the magmatic zircon at that analysis point, U represents the uranium content in the magmatic zircon at that analysis point, and Ti represents the titanium content in the magmatic zircon at that analysis point. And / or, the average oxygen fugacity value f O2 The following calculation model is used: f O2 =( f O2 1+ f O2 2+……… f O2 n) / n。 4. The evaluation method according to claim 1, characterized in that, The calculation of the magma water content includes: analyzing the content of major element oxides and trace elements in the amphibole using electron probe microanalysis, wherein the major element oxides include Na2O, K2O, CaO, MgO, FeO, Al2O3, and SiO2, and the trace elements include Cl and F; and calculating the magma water content using the Amp-TB2 model based on the analysis results.

5. The evaluation method according to claim 4, characterized in that, In the analysis of major element oxides and trace elements, the analytical conditions for major element oxides were 15 kV accelerating voltage, 5 nA beam current, and 5 μm beam spot diameter. The content of Na2O and K2O was measured using a peak count time of 10 s and a background count time of 5 s, while the content of other major element oxides was measured using a peak count time of 20 s and a background count time of 10 s. The analytical conditions for trace elements were 15 kV accelerating voltage, 20 nA beam current, and 15 μm beam spot diameter, with a peak count time of 120 s and a background count time of 60 s.

6. The evaluation method according to claim 1, characterized in that, The calculation of the aluminum saturation index includes: performing X-ray fluorescence spectrometry and / or inductively coupled plasma atomic emission spectrometry analysis on the sampled material to obtain its whole-rock chemical composition and the contents of Al2O3, Na2O, K2O and CaO; and obtaining the aluminum saturation index (ASI) using the following formula: ASI = nAl₂O₃ / (nNa₂O + nK₂O + nCaO) Wherein, nAl2O3, nNa2O, nK2O and nCaO are the molar percentages of Al2O3, Na2O, K2O and CaO, respectively.

7. The evaluation method according to claim 1, characterized in that, in, The concentrations of Cu, Au, and Mo in the initial melt are set to 50 ppm, 2 ppb, and 2 ppm, respectively; and / or, the concentration of Cl in the magma at the start of water saturation, i.e., after 1 wt% magma crystallization, is set to 2000, 2300, and 2500 ppm, respectively; and the chloride concentration of the first batch of exudate is set to 1, 2, and 4 mol / kg H2O.

8. The evaluation method according to claim 1, characterized in that, The magma-mineral partition coefficients for Cu, Au, and Mo are set to 0.2, 0.1, and 0.2, respectively.

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