A quality balance method based on multi-element proportion deviation collaborative analysis

Abstract

This invention relates to the field of geomathematical geology, and particularly to a mass balance method based on multi-element proportional deviation synergistic analysis. The method includes: S1 data extraction and preprocessing; S2 PD matrix initialization; S3 PD matrix calculation and filling; S4 determination of inactive elements based on proportional deviation analysis; and S5 mass balance calculation, which calculates the migration degree of each element relative to the initial content of the original rock, thereby comprehensively evaluating the activity intensity and migration behavior characteristics of different elements during rock alteration, thus achieving a quantitative assessment of element migration behavior during rock alteration. The mass balance method based on multi-element proportional deviation synergistic analysis provided by this invention does not rely on traditional graphical discrimination methods, can accurately identify inactive elements in the data set, greatly improves computational efficiency and accuracy, and possesses high efficiency and universality. It can effectively perform computational analysis on element depletion states in complex geological environments.

Description

Technical Field

[0001] This invention relates to the field of geomathematical geology, and particularly to a mass balance method based on multi-element proportional deviation synergistic analysis. It is applied to the geochemical composition analysis of rocks after complex physicochemical processes (such as weathering, water-rock reaction, metamorphism, magmatic hydrothermal processes, mineralization, etc.), and has applications in strategic metals, oil and gas, and other mineral resources. Background Technology

[0002] Problems with existing mass balance calculations:

[0003] Mass balance, also known as the law of conservation of mass, states that in any system undergoing a complex physicochemical response, the total mass of the input and initial mass of the system is always equal to the total mass of the residual and output mass; that is, input mass + initial mass = output mass + residual mass. Based on this conservation relationship, the trajectory of elemental abundance changes during the reaction process can be determined, laying a theoretical foundation for explaining the evolution path of the system. In rock systems, physicochemical responses are diverse, and after geological processes such as weathering, water-rock reactions, metamorphism, magmatic-hydrothermal processes, and mineralization, the abundance of inert elements shows the smallest variation. Earth science research uses mass balance calculations to quantitatively characterize the degree of elemental depletion within rocks, which has become a key means of revealing the mechanisms of rock evolution.

[0004] For ease of description, the physicochemical processes of geological processes will be referred to as alteration in the following text. Rocks that have undergone alteration are called protoliths, and rocks that have undergone alteration are called altered rocks.

[0005] In the current field of Earth sciences, mass balance calculations mainly rely on the Isocon graphical method. This method was proposed by Grant in the international journal *Economic Geology* in 1986. The core idea is to analyze the elemental depletion within rocks by analyzing the fitting relationship of the slopes of element ratios (e.g., ...). Figure 1The specific steps are as follows: ① Construct an Isocon diagram: the x-axis represents the element concentration of the original rock (C0), and the y-axis represents the element concentration of the altered rock (C1). Elements are plotted in the diagram using their pre-alteration and post-alteration concentrations (C0, C1) as coordinates. ② Draw the Isocon line: In the Isocon diagram, by identifying and selecting relatively inactive elements during metamorphism (usually empirically selected elements such as Al2O3, TiO2, Zr, Nd, and REE), a straight line passing through or near the origin is fitted based on the positions of these elements in the diagram. This straight line is the Isocon line, and its slope reflects the boundary line where element concentration remains unchanged during alteration. ④ Determine element concentration depletion: In the Isocon diagram, elements located above the Isocon line indicate that after alteration, the concentration of this element is relatively enriched, having been replenished from the external environment; elements located below the Isocon line indicate that after alteration, the concentration of this element is relatively depleted, indicating that the element has migrated out of the system. ⑤ Mass balance calculation: By using the ratio of the slope of the line connecting the element point to the origin to the slope of the Isocon line, or by analyzing the relative vertical distribution and distance of a single element point from the Isocon line, the percentage increase or decrease of an element relative to inactive elements is quantitatively calculated. The result represents the elemental deficit state after rock alteration.

[0006] As can be seen from the calculation method based on mass balance, accurately identifying inactive elements and using them as a reference is the foundation for precise analysis of elemental gains and losses. However, the traditional Isocon graphical method has very obvious technical shortcomings.

[0007] On a theoretical level: selecting inactive elements based on experience is not universally applicable across different geological contexts. Using inactive elements as the calculation standard based on experience often leads to significant errors in mass balance calculations. For example, aluminum (Al), which is generally considered an inactive element, cannot be classified as such in magmatic systems due to substantial losses during partial melting.

[0008] In terms of technical methods: ① It has methodological limitations. The traditional Isocon method relies entirely on graphical determination. It cannot perform mass balance calculations and analyses on complex systems with multiple elements (both major and trace elements) and multiple components. ② The analysis time increases exponentially with the amount of data, resulting in time-consuming and inefficient methodological limitations. ③ It lacks universality. Mass balance calculations are also commonly used quantitative analysis methods in chemistry and physics. The traditional Isocon method cannot be applied to research outside of earth sciences, and it also requires operators with a strong background in geology.

[0009] It is worth noting that although a series of scholars, such as Lopez-Moro (2012), have made improvements to the Isocon graphical method, no breakthrough has been achieved in the basic algorithm and core settings of mass balance. At present, mass balance calculation still faces fundamental problems such as low accuracy, long time consumption, low efficiency and poor universality in determining inactive elements.

[0010] In general, existing mass balance methods suffer from problems such as difficulty and inaccuracy in selecting inactive elements, low computational precision (due to large errors caused by multiple calculations based on diagrams), poor efficiency, and limited applicability. Furthermore, they are difficult to perform mass balance calculations and analyses in complex geological environments, leading to significant challenges and debates in the accurate analysis of element migration and deficits in geological systems. There is an urgent need for more advanced and reliable mass balance calculation methods.

[0011] The references are as follows:

[0012] Gresens, RL, 1966, Composition-volume-relationships of metasomatism: Chemical Geology, v. 2, p. 47-65.

[0013] Grant, JA, 1986, The Isocon diagram – a simple solution to Gresens' equation for metasonatic alteration: Economic Geology, v. 81, p. 1976-1982.

[0014] Grant, JA, 2005, Isocon analysis: A brief review of the method and application: Physics & Chemistry of the Earth, v. 30, p. 997-1004.

[0015] López-Moro, FJ, 2012, EASYGRESGRANT—A Microsoft Excel spreadsheet to quantify volume changes and to perform mass-balance modeling inmetasomatic systems. Computers & Geosciences, v. 39, p.191-196.

[0016] Gresens, RL, 1967. Composition-volume relationships of metasomatism. Chemical Geology 2, 47–65. Summary of the Invention

[0017] To overcome or alleviate one or more of the above-mentioned technical problems, the purpose of this invention is to provide a mass balance method based on multi-element proportional deviation collaborative analysis. This method breaks through the high dependence on graphical interpretation in traditional mass balance methods, establishing a simple and accurate mass balance determination method that does not require complex diagrams. The mass balance method provided by this invention, which does not rely on graphical discrimination, can accurately identify inactive elements in the data set, greatly improving computational efficiency and accuracy. It possesses high efficiency and universality, and can effectively perform computational analysis on elemental depletion states in complex geological environments.

[0018] In the following description of the invention, protolith refers to rock that has not undergone physicochemical reactions, and altered rock refers to rock that has undergone physicochemical reactions. m represents an active element; i represents an inactive element. Represents the content of active elements in the original rock; It represents the content of active elements in altered rocks after physicochemical reactions; This represents the content of immobile elements in the original rock; This represents the content of immobile elements in altered rocks after physicochemical reactions. Data acquisition is based on geochemical testing and analysis methods, such as electron probe microanalysis, which are not covered by this invention. This represents the amount of change to the active element.

[0019] This invention provides the following technical solution:

[0020] A quality balancing method based on multi-element proportional deviation synergistic analysis includes the following steps:

[0021] S1. Data Extraction and Preprocessing:

[0022] Three parameters for extracting elemental geochemical data: element name, element content in the protolith, and the elemental composition. and elemental content in altered rocks And perform data validity checks to remove outliers and missing items;

[0023] S2, PD matrix initialization:

[0024] Suppose there are n types of elements. Construct an n×n blank numerical matrix as the PD matrix framework; the row index of the matrix represents the target element. The column index represents the reference element. Establish a "target-reference" element pair mapping relationship;

[0025] S3, PD matrix calculation and filling:

[0026] For each matrix position (i,j), where i is the target element index - row and j is the reference element index - column, the PD value is calculated according to the following formula:

[0027] (4)

[0028] In the formula, m corresponds to row index i, and i corresponds to column index j;

[0029] Furthermore, we can obtain:

[0030] (5)

[0031] in, The mass loss or increase caused by the migration of active elements;

[0032] Further transformation of equation (5) yields:

[0033] (6)

[0034] Fill the corresponding positions in the matrix with the calculation results of equation (4); the diagonal element (i, i) represents the self-comparison of the same element, and its PD value is set to 0; after completing all the calculations, the complete PD matrix is ​​obtained;

[0035] Through equation (6). This is the mass balance constant of the system's physicochemical reactions;

[0036] S4. Determination of inactive elements based on proportional deviation analysis:

[0037] The distribution of PD values ​​for each reference element is analyzed column by column. The reference element group with the closest PD values ​​and the smallest difference among all target element rows is selected as the inactive element group. Then, the PD values ​​corresponding to all selected inactive elements in each row are averaged to obtain the average proportional deviation value of the target elements in that row. ;

[0038] S5. Mass balance calculation:

[0039] Based on S4 According to the following formula:

[0040] (7)

[0041] Calculate the absolute amount of migration of each element. ,like > 0 indicates that the element was introduced during the alteration process; if If < 0, it indicates carry-out; relative migration calculation The following formula is used:

[0042] (8)

[0043] The migration degree of each element relative to the initial content of the original rock is calculated, thereby comprehensively assessing the activity intensity and migration behavior characteristics of different elements in the rock alteration process, thus achieving a quantitative assessment of element migration behavior in the rock alteration process.

[0044] Compared with the traditional Isocon graphical method, this invention demonstrates significant technical advantages in geochemical mass balance analysis, specifically in the following five aspects:

[0045] 1. Advantages of Objectivity and Automation: Traditional Isocon methods rely on researchers' subjective judgment to select inactive elements and determine isoconcentration lines, which is subject to human bias and uncertainty. This invention, through the developed PD algorithm and corresponding analysis matrix, objectively determines inactive elements based on the principle of minimizing numerical differences, thus improving the reproducibility of results. This method is not limited by the methodology of graphical methods and can simultaneously process mass balance calculations for multiple elements in batches, significantly improving processing efficiency and completing mass balance calculations within minutes.

[0046] 2. Multi-algorithm verification mechanism: This method uses multi-element proportional deviation collaborative analysis for cross-validation, which enhances the robustness of inactive element identification; while the Isocon method is usually based on a single judgment criterion, which is easily affected by abnormal element behavior, resulting in large errors in the calculation results.

[0047] 3. Higher degree of quantification: This method achieves dual quantitative assessment of absolute and relative migration through precise calculation of the equilibrium constant PD, providing more comprehensive information on element migration. In contrast, the Isocon method mainly relies on graphical analysis, which is limited by the graphical methodology and has lower quantitative accuracy.

[0048] 4. Ease of Data Processing: Based on the invented PD algorithm, mass balance calculations only require ensuring accuracy to obtain reliable results, eliminating the need for complex diagram construction and judgment. Furthermore, the identification of inactive elements is simple, requiring no specialized geoscience background from the staff. In contrast, the Isocon method has significant shortcomings in data preprocessing and inactive element identification, often leading to controversial calculation results.

[0049] 5. Wide applicability: Compared with the Isocon graphical method, this method is based on numerical calculation principle and multi-element proportional deviation analysis principle, and has relatively less dependence on specific geological environment or alteration type. It can be applied in a variety of earth science backgrounds and has universality. Attached Figure Description

[0050] Figure 1 The traditional Isocon graphical method provided in the background of this application is used to determine inactive elements and perform mass balance calculations to determine uniform deficit (Image source: López-Moro, FJ, 2012, EASYGRESGRANT—A Microsoft Excel spreadsheet to quantify volume changes and to perform mass-balance modeling in metasomatic systems. Computers & Geosciences, v. 39, p.191-196.).

[0051] Figure 2 A flowchart of a quality balance method based on multi-element proportional deviation collaborative analysis provided in an embodiment of this application.

[0052] Figure 3 The original data list provided for Embodiment 1 of this application.

[0053] Figure 4 The PD matrix provided in Embodiment 1 of this application.

[0054] Figure 5 This is the inactive element determination marker provided in Embodiment 1 of this application.

[0055] Figure 6 This is a list of the average values ​​of the PD values ​​of inactive elements provided in Embodiment 1 of this application.

[0056] Figure 7 A list of mass defects of the target element provided in Embodiment 1 of this application.

[0057] Figure 8 The PD matrix provided in Embodiment 2 of this application.

[0058] Figure 9 This is the list of inactive elements highlighted in yellow provided in Embodiment 2 of this application.

[0059] Figure 10 This is a list of mass balance constants PD_mean for some elements provided in Embodiment 2 of this application.

[0060] Figure 11This is a list of mass balance constants PD_mean for some other elements provided in Embodiment 2 of this application.

[0061] Figure 12 The calculation results of absolute and relative migration amounts of some principal elements provided in Embodiment 2 of this application.

[0062] Figure 13 The calculation results of absolute and relative migration amounts of some other principal elements provided in Embodiment 2 of this application. Detailed Implementation

[0063] This invention, based on fundamental geological principles, develops a multi-element proportional deviation collaborative calculation method for accurately determining the variation patterns of element content in geological systems. This method overcomes the technical limitations of traditional mass balance analysis, abandoning the traditional analysis model that relies on graphical interpretation and a single reference element, and constructs an innovative algorithm framework based on multi-element collaborative analysis and proportional deviation calculation. By introducing a dynamic weight optimization mechanism, intelligent processing of multi-element geochemical data is achieved, establishing an end-to-end analytical technique from raw data to accurate calculation of element migration. This method innovatively combines multi-element proportional deviation analysis with statistical optimization algorithms, enabling precise identification of inactive element combinations in rock systems and high-precision calculation of mass balance, accurately quantifying the magnitude of element introduction and migration during rock alteration.

[0064] This method demonstrates broad applicability in the field of Earth sciences and can be effectively applied to the analysis of various complex geological environments, such as complex water-rock reaction systems, multi-element coupled migration processes, and multi-stage geological processes. It provides an innovative technical solution with higher computational accuracy, better analytical efficiency, and wider applicability for the quantitative assessment of element migration in fields such as mineralogy, petrology, environmental earth sciences, and resource exploration.

[0065] like Figure 2 In this invention, the balancing algorithm is constructed based on the proportional deviation mass balancing algorithm (hereinafter referred to as the PD algorithm), and the specific method is as follows:

[0066] Based on the Gresen equation (Gresens, 1967), the composition of rocks changes after physicochemical reactions. ) expressed as Where Fp is a system constant, which remains unchanged within the same system; The content of this element in the altered rock. This represents the abundance of this element in the original rock. For mobile elements, due to element migration and changes... For inactive elements, the inertia of interesting non-transferable elements is ideal (without considering experimental test errors). Based on the fact that Fp remains constant in a reaction system, it can be concluded that the compositional ratio between the two different elements is consistent in the protolith and altered rock.

[0067] Assuming that the content of active elements in the protolith was [value missing] before the rock underwent physicochemical reactions. The content of inactive elements is In altered rocks that have undergone physicochemical reactions, the content of active elements is: The content of inactive elements is Based on the Gresen equation, if the mass loss or increase caused by the migration of active elements is considered ( Taking into account the active element (m) and the inactive element (i), the consistency of the compositional ratio between the original rock and the altered rock in the active and inactive elements can be expressed as:

[0068] (1)

[0069] Formula (1), when transformed and expressed as a percentage, can be converted to:

[0070] (2)

[0071] Furthermore, because in the same reaction system, the percentage content of any two components n and p differs between the original rock and the altered rock ( The formula for calculating ) is:

[0072] x100 (3)

[0073] based on The expression method, for active element m and inactive element i, shows the difference in their percentage content. for:

[0074] (4)

[0075] By combining equations (2) and (4), we can obtain:

[0076] (5)

[0077] Further transformation of equation (5) yields:

[0078] (6)

[0079] From equations (5) and (6), it can be concluded that after the physicochemical reaction, the mass loss or increase of the active element due to migration occurs. The difference can be determined by the percentage content of active and inactive elements. Decision. Therefore It can be used as the mass balance constant for the physicochemical reactions of the system. Further, based on the consistency of Fp in the Gresen equation, the fusion equation (4) shows that, under ideal conditions, different inactive elements... (n = 1, 2, 3…n) The values ​​should be the same, meaning the difference should be 0. That is, for the active element m, taking different inactive elements i as a baseline, the mass balance constant... They should be the same. In other words, considering the errors in actual experimental tests, different inactive elements... (n = 1, 2, 3…n) The values ​​should be extremely similar, that is, the values ​​calculated from different inactive elements should be very similar. The values ​​should be extremely similar.

[0080] Therefore, based on equation (4) Similar situations can be used to identify inactive elements. Furthermore, the values ​​calculated from different inactive elements... average This can be used as the mass balance constant of the reaction system. Therefore, the mass change of active elements in altered rocks can be further derived based on the above and equation (6).

[0081] (7)

[0082] It calculates the quality loss or increase of active elements due to migration, based on all inactive elements in the system.

[0083] The present invention will now be described in detail with reference to embodiments and accompanying drawings. However, it should be understood that the embodiments and drawings are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. All reasonable modifications and combinations included within the inventive spirit of the present invention fall within the scope of protection of the present invention.

[0084] The present invention will be further described below with reference to the accompanying drawings.

[0085] Example 1

[0086] This embodiment uses elemental mass balance analysis of a typical hydrothermal alteration deposit as an example, illustrating the application of the mass balance method provided in this application to hydrothermal deposits. The formation of hydrothermal deposits involves extremely complex water-rock reactions, accompanied by large-scale element migration and mineral phase transformations. Traditional Isocon methods face numerous challenges and limitations when dealing with such complex geological systems. Given that mass balance calculations can quantitatively analyze the elemental behavior patterns during metamorphic processes, their application in metamorphic rock research has significant representativeness and methodological value.

[0087] Therefore, the following section takes the specific application of this invention in mineral deposits as a typical case, and analyzes in detail its calculation process, method principle and the obtained geochemical results. The data presented are ideal data from numerical simulation. The simplicity of the data but its systematic nature can fully demonstrate the effectiveness and superiority of this method in the study of complex geological systems.

[0088] (1) Original data collection: C0 is the elemental content in the original rock, and C1 is the elemental content after the water-rock reaction, see Figure 3 List;

[0089] (2) Construction of the PD matrix, see Figure 4 List; the column index of the matrix is ​​the reference element i, the row index is the target element m, and the PD value in the matrix is ​​calculated according to equation (4).

[0090] (3) Determination of inactive elements, see Figure 5 The list; as shown in the matrix, the PD contents of Al2O3, MgO, TiO22, and P2O5 are closest (they are the same here), therefore these elements are selected as inactive elements. Thus, the mass balance constant corresponding to each target element m (row index) is the average PD value of the selected inactive elements in each row. Therefore, we can obtain... Figure 6 List.

[0091] (4) Mass balance calculation: The PD_mean value of the target element and its content in the original rock have been obtained, based on equation (7) This allows us to determine the mass defect status of the target element, see [link / reference]. Figure 7 The list displays numbers to two decimal places, a standard practice in geosciences.

[0092] The data in the list above shows that:

[0093] 1) Strong Potassium Alteration Characteristics: The data clearly indicate a strong potassium alteration process. The most significant evidence is the substantial increase in K₂O, with an absolute increase of 1.20 wt% and a relative increase of up to 26%, indicating that the ore-forming hydrothermal fluids were rich in potassium components. The increase in Fe₂O₃ (absolute amount +0.55 wt%, relative +8%) is usually associated with the precipitation of metallic sulfides such as pyrite or the formation of biotite, and is a common phenomenon accompanying potassium alteration. The slight change in Na₂O (+0.07 wt%) indicates that the alteration process was dominated by potassium addition, with little sodium replacement, which may be related to the fluid properties or the composition of the protolith minerals. At the same time, the slight loss of CaO and MnO further corroborates the alteration process in which calcium-bearing minerals such as plagioclase in the protolith were replaced by potassium-bearing minerals such as potassium feldspar or sericite.

[0094] (2) Geological significance and prospecting indications: The element migration patterns revealed by this mass balance simulation are typical of hydrothermal deposit alteration systems, particularly closely matching the characteristics of the core alteration zone—the potassic alteration zone—of porphyry copper-molybdenum-gold deposits. This result indicates that the simulated geological environment underwent a large-scale, intense activity of potassic hydrothermal fluids. This alteration environment is a direct product and important indicator of a large-scale hydrothermal mineralization system, strongly suggesting that the region possesses enormous potential for forming porphyry deposits and is a key target area for future mineral exploration.

[0095] The aforementioned element migration model perfectly illustrates the potassic characteristics during the water-rock reaction process and the geochemical evolution path under the influence of hydrous and potassium-rich fluid systems. Based on numerical theoretical data, the correctness and effectiveness of this invention are fully verified. This embodiment fully demonstrates the technical advantages of this invention: ① It eliminates the need for traditional graphical methods through algorithm optimization, improving efficiency; ② It can be applied to complex systems to accurately identify inactive elements and quantitatively calculate the migration patterns of each element.

[0096] Example 2

[0097] This embodiment is implemented using element-depleted mass balance in Finnmark meta-diabase from Norway.

[0098] This embodiment illustrates the application of the mass balance method provided in this application to metamorphic rocks. The formation of metamorphic rocks is an extremely complex physicochemical process, accompanied by large-scale element migration and mineral phase transformations. Traditional Isocon methods face numerous challenges and limitations when dealing with such complex geological systems. Given that mass balance calculations can quantitatively analyze the elemental behavior patterns during metamorphism, their application in metamorphic rock research has significant representativeness and methodological value.

[0099] Therefore, the following section takes the specific application of this invention in metamorphic rock mass balance calculation as a typical case, and analyzes in detail its calculation process, method principle and the obtained geochemical results, so as to fully demonstrate the effectiveness and superiority of this method in the study of complex geological systems.

[0100] This embodiment collects major element (wt%) and trace element (ppm) data from the Finnmark metamorphic diabase in Norway, and presents them according to "elements (C0i, C1i)".

[0101] Major elements: SiO2 (47.59, 45.52), Al2O3 (13.84, 13.42), Fe2O3 (16.18, 15.7), MgO (6.89, 6.52), CaO (10.33, 9.78), Na2O (1.09, 0.72), K2O (0.5, 2.85), TiO2 (2.17, 2.41), P2O5 (0.19, 0.21), MnO (0.3, 0.24).

[0102] Trace elements: V (437.37, 422, 53), Cr (273.93, 150.69), Co (50.84, 42.55), Ni (74.06, 54.07), Rb (8.01, 85.21), Sr (47.44, 152.79), Y (58.85, 62.48), Zr (121.10, 163.81), Nb (3.30, 3.20), Hf (3.80, 5.11), Ta (0.2, 0.2), La (4.00, 9.91), Ce (13.61, 24.53), Pr (2.56, 3.73), Nd (15.81, 20.13), Sm (5.51, 6.53)

[0103] Step 1: PD matrix construction: Based on equation (4), we can obtain... Figure 8 List results;

[0104] Step 2: Determination of Inactive Elements: Using multi-element ratio deviation synergistic analysis, the inactive elements were identified as: Al2O3, Fe2O3, V, and Nb. Figure 9 (Columns highlighted in yellow in the list).

[0105] Step 3: Calculation of mass balance constant: Based on the selection of inactive elements in Step 2, the mass balance constant PD_mean for each element is... Figure 10 Lists and Figure 11 List:

[0106] Step 4: Mass balance calculation:

[0107] The formula for calculating the absolute migration amount is equation (7).

[0108] The formula for calculating the relative migration amount is equation (8).

[0109] The results of the principal element calculations can be found in [link to calculation]. Figure 12 List (displayed according to the standard geoscience format of retaining 2 decimal places);

[0110] The results of the trace element calculations can be found in [link to data]. Figure 13 List;

[0111] The above mass balance calculation results show that:

[0112] (1) Significant potassium replacement: The extreme enrichment of K2O (+456%) and Rb (+939%) is closely related, confirming a strong potassium replacement process; at the same time, the significant depletion of Na2O (-36%) and CaO (-7%), together with the large enrichment of Sr (+215%), indicates the decomposition and recrystallization of plagioclase.

[0113] (2) Classical metamorphic characteristics of basic rocks: SiO2, Al2O3 and Fe2O3 show slight and consistent depletion (-5% to -7%), indicating that the overall chemical framework of the rock remains relatively stable; the synergistic depletion of MgO (-8%) and compatible elements Ni (-29%) and Co (-18%) clearly reflects the systematic transformation of the mafic mineral phase.

[0114] (3) Clear mineral phase transformation: The extreme enrichment of K element reveals a typical potassium feldspar reaction mechanism - "plagioclase + K + Fluid → Potassium feldspar + Na + + Ca 2+ This process promotes the formation and development of chlorite and mica-like minerals in the metamorphic environment.

[0115] (4) Stability of accessory minerals: The slight enrichment of TiO2 (+8%) is highly consistent with the relative stability of titanium accessory minerals such as rutile during the metamorphic process, further verifying the rationality of the metamorphic conditions.

[0116] The above-mentioned element migration model fits well with the geochemical evolution path of the diabase protolith transforming into schist facies under the action of a water-bearing, potassium-rich fluid system. It is highly consistent with the research results of Rice (1987) and Corfu et al. (2014) in the Finnmark meta-diabase in Norway, which fully verifies the effectiveness and reliability of the method of the present invention.

[0117] This embodiment fully demonstrates the technical advantages of the present invention: ① It can be applied in complex system applications to accurately identify inactive elements and quantitatively calculate the migration patterns of each element. ② Through algorithm optimization, it abandons the traditional graphical method, eliminating the need for graphical discrimination and significantly improving work efficiency.

[0118] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A quality balance method based on multi-element proportional deviation synergistic analysis, characterized in that: It includes the following steps: S1. Data Extraction and Preprocessing: Three parameters for extracting elemental geochemical data: element name, element content in the protolith, and the elemental composition. and elemental content in altered rocks And perform data validity checks to remove outliers and missing items; S2, PD matrix initialization: Suppose there are n types of elements. Construct an n×n blank numerical matrix as the PD matrix framework; the row index of the matrix represents the target element. The column index represents the reference element. Establish a "target-reference" element pair mapping relationship; S3, PD matrix calculation and filling: For each matrix position (i,j), where i is the target element index - row and j is the reference element index - column, the PD value is calculated according to the following formula: （4） In the formula, m corresponds to row index i, and i corresponds to column index j; Furthermore, we can obtain: （5） in, The mass loss or increase caused by the migration of active elements; Further transformation of equation (5) yields: （6） Fill the corresponding positions in the matrix with the calculation results of equation (4); the diagonal element (i, i) represents the self-comparison of the same element, and its PD value is set to 0; after completing all the calculations, the complete PD matrix is ​​obtained; Through equation (6). This is the mass balance constant of the system's physicochemical reactions; S4. Determination of inactive elements based on proportional deviation analysis: The distribution of PD values ​​for each reference element is analyzed column by column. The reference element group with the closest PD values ​​and the smallest difference among all target element rows is selected as the inactive element group. Then, the PD values ​​corresponding to all selected inactive elements in each row are averaged to obtain the average proportional deviation value of the target elements in that row. ; S5. Mass balance calculation: Based on S4 According to the following formula: （7） Calculate the absolute amount of migration of each element. ,like > 0 indicates that the element was introduced during the alteration process; if If the value is less than 0, it indicates carry-out; relative migration calculation The following formula is used: （8） The migration degree of each element relative to the initial content of the original rock is calculated, thereby comprehensively assessing the activity intensity and migration behavior characteristics of different elements in the rock alteration process, thus achieving a quantitative assessment of element migration behavior in the rock alteration process.

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