Method of determining the origin of sandstone

Abstract

Embodiments of the present application relate to the field of testing or analyzing materials by means of determining chemical or physical properties of the materials, and particularly relate to a method for determining the provenance of sandstone, comprising: obtaining a sandstone sample to be determined provenance and a control sample with known provenance, determining the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, illite / montmorillonite mixed layer in the sandstone sample and the control sample; determining the chemical weathering index of the sandstone sample and the control sample; determining the ratio of SiO2 content to Al2O3 content of the sandstone sample and the control sample; determining the provenance distribution rule of the control sample; and determining the provenance of the sandstone sample according to the chemical weathering index, the ratio of SiO2 content to Al2O3 content, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, illite / montmorillonite mixed layer of the control sample and the sandstone sample. The method provided by the embodiments of the present application can effectively and accurately determine the provenance of the sandstone sample to be determined provenance.

Description

Technical Field

[0001] Embodiments of this application relate to the field of testing or analyzing materials by measuring their chemical or physical properties, and specifically to a method for determining the origin of sandstone. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] Sandstone, a common sedimentary rock, is widely distributed across the Earth's surface, and its occurrence is closely related to geological history and sedimentary environment. Determining the location of sandstone is beneficial for reconstructing paleogeographic environments, the evolutionary history of sedimentary basins, and tectonic processes. Sandstone typically contains important mineral resources such as uranium and copper; therefore, determining its location also helps in identifying the distribution patterns of these mineral resources. Thus, it is necessary to study the techniques for determining sandstone locations.

[0004] Currently, there are still many limitations in the technology for determining the origin of sandstone. Summary of the Invention

[0005] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] To address the aforementioned issues, embodiments of this application provide a method for determining the origin of sandstone.

[0007] The method includes the following steps: S10, obtaining multiple sandstone samples from locations to be determined; S20, preparing multiple sandstone samples into multiple sandstone samples of a first grain size and multiple sandstone samples of a second grain size, wherein the first grain size is larger than the second grain size; S30, determining the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples of the first grain size; S40, determining the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the multiple sandstone samples of the second grain size; S50, based on the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the multiple sandstone samples of the second grain size determined in step S40, determining the chemical weathering index and the ratio of SiO2 content to Al2O3 content of the multiple sandstone samples of the second grain size; 60. Obtain multiple control samples with known origins, and perform steps S20-S50 on the multiple control samples; S70. Based on the origins of the multiple control samples, the chemical weathering index of the multiple control samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, and the ratio of SiO2 content to Al2O3 content in the multiple control samples, determine the origin distribution pattern of the multiple control samples; S80. Based on the chemical weathering index of the multiple sandstone samples, the ratio of SiO2 content to Al2O3 content in the multiple sandstone samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples, and the origin distribution pattern determined in step S70, determine the origin of the multiple sandstone samples whose origins are to be determined.

[0008] The method provided in this application determines the origin distribution pattern of a reference sample by determining its chemical weathering index, the ratio of SiO2 content to Al2O3 content, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers. This allows for the effective determination of the origin of a sandstone sample based on the origin distribution pattern of the reference sample, the chemical weathering index of the sandstone sample, the ratio of SiO2 content to Al2O3 content, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers. Furthermore, it reduces the complexity of determining the origin of a sandstone sample, improves the efficiency of determination, and enhances the accuracy of the determined sandstone origin. The accuracy of the provenance of sandstone samples is crucial for providing reliable and accurate technical support for geological research and resource exploration. Furthermore, by preparing the sandstone samples and control samples into first- and second-grained samples, the processing work can be minimized, reducing intermediate steps and the likelihood of contamination. This facilitates accurate measurement of the aforementioned contents and chemical weathering index. Additionally, preparing the sandstone samples and control samples into first- and second-grained samples makes it easier to measure the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, illite / montmorillonite mixed layers, as well as the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the samples. Attached Figure Description

[0009] Other objects and advantages of this application will become apparent from the following description of embodiments of this application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of this application.

[0010] Figure 1 This is a flowchart illustrating the method provided in an embodiment of this application.

[0011] Figure 2 It is based on Figure 1 The diagram shows the relationship between multiple control samples and multiple classification functions determined by the method.

[0012] Explanation of reference numerals in the attached figures:

[0013] 21. Type I sample; 22. Type II sample; 23. Type III sample; 24. Type IV sample.

[0014] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding. Detailed Implementation

[0015] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0016] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0017] In related technologies, the chemical and mineral composition of sandstone is used to determine its origin. However, in the process of determining the origin of sandstone, there are problems such as ineffective determination and low accuracy.

[0018] To address the aforementioned issues, embodiments of this application provide a method for determining the origin of sandstone.

[0019] See Figure 1 , Figure 1This is a flowchart illustrating a method provided in an embodiment of this application. The method includes the following steps: S10, obtaining multiple sandstone samples of unknown origin; S20, preparing multiple sandstone samples into multiple sandstone samples of a first grain size and multiple sandstone samples of a second grain size, wherein the first grain size is larger than the second grain size; S30, determining the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples of the first grain size; S40, determining the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the multiple sandstone samples of the second grain size; S50, based on the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the multiple sandstone samples of the second grain size determined in step S40, determining the chemical weathering index and SiO2 content of the multiple sandstone samples of the second grain size. S60. Obtain multiple control samples with known origins and perform steps S20-S50 on the multiple control samples; S70. Determine the origin distribution pattern of the multiple control samples based on the origin of the multiple control samples, the chemical weathering index of the multiple control samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, and the ratio of SiO2 content to Al2O3 content in the multiple control samples; S80. Determine the origin of the multiple sandstone samples whose origin is to be determined based on the chemical weathering index of the multiple sandstone samples, the ratio of SiO2 content to Al2O3 content in the multiple sandstone samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples, and the origin distribution pattern determined in step S70.

[0020] The method provided in this application determines the origin distribution pattern of a reference sample by determining its chemical weathering index, the ratio of SiO2 content to Al2O3 content, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers. This allows for the effective determination of the origin of a sandstone sample based on the origin distribution pattern of the reference sample, the chemical weathering index of the sandstone sample, the ratio of SiO2 content to Al2O3 content, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers. Furthermore, it reduces the complexity of determining the origin of a sandstone sample, improves the efficiency of determination, and enhances the accuracy of the determined sandstone origin. The accuracy of the provenance of sandstone samples is crucial for providing reliable and accurate technical support for geological research and resource exploration. Furthermore, by preparing the sandstone samples and control samples into first- and second-grained samples, the processing work can be minimized, reducing intermediate steps and the likelihood of contamination. This facilitates accurate measurement of the aforementioned contents and chemical weathering index. Additionally, preparing the sandstone samples and control samples into first- and second-grained samples makes it easier to measure the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, illite / montmorillonite mixed layers, as well as the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the samples.

[0021] In some embodiments, the first particle size can be 60 to 80 mesh to facilitate the measurement of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in samples with the first particle size. For example, the first particle size can be 70 mesh.

[0022] In some embodiments, the second particle size can be 200 mesh to facilitate the measurement of the SiO2, K2O, Na2O, CaO and Al2O3 content in the sample with the second particle size.

[0023] In some embodiments, in step S20, each sandstone sample may be processed to make a sandstone sample of a first grain size and a sandstone sample of a second grain size, i.e., the number of sandstone samples of the first grain size and the number of sandstone samples of the second grain size are the same as the number of sandstone samples obtained; in step S60, the obtained control sample is processed in the same way.

[0024] In some embodiments, in step S60, when obtaining multiple control samples, at least three control samples are obtained from each origin. In such embodiments, obtaining at least three control samples from each origin helps to avoid random errors in subsequent processes and improves the accuracy of subsequently determined content and chemical weathering index.

[0025] In some embodiments, step S70 may further include the following steps: S71, determining multiple characteristic values ​​related to the origin of the control samples based on the chemical weathering index of multiple control samples and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, as well as the ratio of SiO2 content to Al2O3 content in the multiple control samples; S72, determining the contribution rate of each characteristic value in determining the origin based on the multiple characteristic values; S73, determining multiple characteristic values ​​whose sum of contribution rates is greater than a preset contribution rate value based on the contribution rate of each characteristic value in determining the origin; S74, determining multiple characteristic values ​​based on the multiple characteristic values ​​determined in step S73. The following steps are taken: S74, S75, S76, S777, S78, S79, S71, S72, S73, S74, S75, S76, S77, S78, S79, S71, S72, S73, S74, S75, S76, S77, S78, S79, S71, S72, S73, S74, S75, S76, S77, S78, S79, S71, S72, S73, S74, S76, S77, S79, S71, S72, S73, S74, S76, S77, S79, S72, S74, S76, S77, S79 ...

[0026] In some embodiments, the preset contribution rate value can be 80%.

[0027] In some embodiments, in step S74, the number of classification functions determined is equal to the number of feature values ​​determined in step S73.

[0028] Specifically, the contribution rate of each characteristic value in determining the place of origin conforms to the following relationship:

[0029]

[0030] In the formula, P is the contribution rate of each eigenvalue, and λ is the contribution rate of each eigenvalue. i Let λ be the characteristic value of the contribution rate to be determined. jis the j-th feature value related to the origin of the control sample determined in step S71; n is the number of feature values ​​related to the origin of the control sample determined in step S71, and j is the summation ordinal number.

[0031] In some embodiments, in step S72, the multiple feature values ​​determined in step S71 can be sorted in order of magnitude to facilitate the determination of multiple feature values ​​whose sum of contribution rates is greater than a preset contribution rate value.

[0032] In some embodiments, step S74 may further include the following step: S741, determining that multiple classification functions related to the sandstone's origin conform to the following relationship:

[0033] Y=∑aC i +bX+eR+d,

[0034] In the formula, Y is the classification function value, a, b, e, and d are parameters, and C... i S742. Based on the multiple characteristic values ​​determined in step S73, the chemical weathering indices of multiple control samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple control samples, as well as the ratio of SiO2 content to Al2O3 content in multiple control samples, determine a, b, e, and d. Since the sum of the contribution rates of the multiple feature values ​​determined in step S73 is greater than the preset contribution rate value, the embodiments of this application determine a, b, e, and d based on the multiple feature values ​​determined in step S73, which can not only ensure the accuracy of the determined a, b, e, and d, but also reduce the determination difficulty and improve the determination efficiency. Furthermore, the embodiments of this application determine multiple classification functions related to the sandstone's origin through the above-mentioned relationship, which is beneficial to improving the efficiency of determining the classification functions related to the sandstone's origin.

[0035] In some embodiments, step S71 may further include the following steps: S711, determining the mean of the chemical weathering indices of multiple control samples based on their chemical weathering indices; S712, determining the mean of the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple control samples based on their contents; S713, determining the mean of the ratio of SiO2 content to Al2O3 content in multiple control samples based on their ratios; S714, determining the chemical weathering index of each control sample and the chemical weathering index determined in step S711 based on the mean determined in step S711 and the chemical weathering index of each control sample. S715. Based on the mean values ​​determined in step S712 and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in each control sample, determine the difference between the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in each control sample and the mean values ​​determined in step S712; S716. Based on the mean values ​​determined in step S713 and the ratio of SiO2 content to Al2O3 content in each control sample, determine the difference between the ratio of SiO2 content to Al2O3 content in each control sample and the mean values ​​determined in step S713; S717. Based on the differences determined in steps S714, S715, and S716, determine multiple characteristic values ​​related to the origin of the control samples. In such an embodiment, multiple characteristic values ​​related to the origin of the control samples are determined based on the differences between the chemical weathering index of each control sample and the mean of the chemical weathering index of the control samples, the differences between the ratio of SiO2 content to Al2O3 content of each control sample and the mean of the ratio of SiO2 content to Al2O3 content of the control samples, and the differences between the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in each control sample and the mean contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the control samples. This ensures that the determined multiple characteristic values ​​related to the origin of the control samples can comprehensively reflect the characteristics of each origin, thereby improving the efficiency and accuracy of subsequently determining the origin of multiple sandstone samples to be determined.

[0036] In some embodiments, step S717 may further include the following steps: S7171, determining a first vector composed of the differences determined in step S714; S7172, determining a plurality of second vectors composed of the differences determined in step S715; S7173, determining a third vector composed of the differences determined in step S716; S7174, determining a matrix composed of the first vector, the plurality of second vectors, and the third vector; S7175, determining an intermediate matrix related to the origin of the control sample based on the matrix determined in S7174; S7176, determining a plurality of eigenvalues ​​related to the origin of the sandstone based on the intermediate matrix determined in S7175.

[0037] Specifically, the matrix D determined in step S7174 is:

[0038]

[0039] Where, d 11 to d m1 d represents the difference determined in step S714. 12 to d m2 d 13 to d m3 d 14 to d m4 d 15 to d m5 d 16 to d m6 d 17 to d m7 This represents the difference determined in step S715; d 18 to d m8 Let m represent the difference determined in step S716, where m is the number of control samples; the intermediate matrix ∑ determined in step S7175 and the matrix D determined in step S7174 satisfy the following relationship.

[0040]

[0041] The intermediate matrix ∑ determined in step S7175 and several eigenvalues ​​related to the sandstone's origin satisfy the following relationship:

[0042] det(∑-λI)=0,

[0043] In the formula, λ is the eigenvalue related to the sandstone's origin, and I is the identity matrix with the same number of elements as the intermediate matrix ∑.

[0044] In some embodiments, step S742 may further include the following step: S7421, determining multiple intermediate vectors V that can be used to determine a, b, e, and d based on the multiple eigenvalues ​​determined in step S73 and the intermediate matrix ∑ determined in step S7175. iS7422, The intermediate vector V determined according to S7421 i The chemical weathering index of multiple control samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple control samples, and the ratio of SiO2 content to Al2O3 content in multiple control samples were used to determine a, b, e, and d.

[0045] Specifically, the multiple eigenvalues ​​determined in step S73, the intermediate matrix ∑ determined in step S7175, and the intermediate vector V i It conforms to the following relationship

[0046] (∑-λ i I)V i =0,

[0047] In the formula, λ i This is the i-th eigenvalue determined in step S73.

[0048] In some embodiments, in step S7422, the chemical weathering index of multiple control samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, and the ratio of SiO2 content to Al2O3 content in the multiple control samples can be correlated with the corresponding intermediate vector V. i Multiply and sum them to determine a, b, e, and d.

[0049] In some embodiments, step S75 may further include the following steps: S751, determining multiple classification function values ​​corresponding to each control sample based on the multiple classification functions determined in step S74, the chemical weathering index of each control sample, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in each control sample, and the ratio of SiO2 content to Al2O3 content in each control sample; S752, determining a relationship diagram between the multiple control samples and the multiple classification functions; S753, determining the position of each control sample in the relationship diagram based on the multiple classification function values ​​corresponding to each control sample; S754, determining the distribution pattern of the multiple control samples based on the positions of the multiple control samples in the relationship diagram and the origin of each control sample. In such embodiments, by determining a relationship diagram of multiple classification functions, it is convenient to visually display and determine the distribution pattern of the control samples through the relationship diagram, thereby facilitating the determination of the origin of the sandstone sample whose origin is to be determined through the distribution pattern of the control samples.

[0050] In some embodiments, step S80 may further include the following steps: S81, determining multiple classification function values ​​corresponding to each sandstone sample based on the chemical weathering index of multiple sandstone samples, the ratio of SiO2 content to Al2O3 content of multiple sandstone samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple sandstone samples, as well as the multiple classification functions determined in step S74; S82, determining the position of each sandstone sample in the relationship diagram based on the multiple classification function values ​​corresponding to each sandstone sample; S83, determining the origin of multiple sandstone samples whose origin is to be determined based on the position of each sandstone sample in the relationship diagram and the distribution pattern of multiple control samples. In such an embodiment, since samples from the same origin are distributed in the same area in the relationship diagram, the position of each sandstone sample in the relationship diagram is determined based on the distribution of the sandstone sample from the origin to be determined in the relationship diagram and the multiple classification function values ​​corresponding to each sandstone sample. Based on the position of each sandstone sample in the relationship diagram and the distribution pattern of multiple control samples, control samples belonging to the same origin as the sandstone sample from the origin to be determined are identified. Thus, the origin of the sandstone sample from the origin to be determined can be determined based on the origin of the control samples, which is beneficial for intuitively and efficiently determining the origin of the sandstone sample from the origin to be determined.

[0051] In some embodiments, prior to step S70, the method further includes: S700, correcting the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples of the first grain size determined in step S30. In step S71, based on the chemical weathering index of multiple control samples and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers corrected in S700, as well as the ratio of SiO2 content to Al2O3 content of the multiple control samples, determining multiple characteristic values ​​related to the origin of the control samples. In this embodiment, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple sandstone samples of the first grain size are first corrected. Then, based on the corrected contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers, multiple characteristic values ​​related to the origin of the control sample are determined. This reduces the complexity of the process of determining multiple characteristic values ​​related to the origin of the control sample and simplifies the operation of determining multiple characteristic values ​​related to the origin of the control sample.

[0052] In some embodiments, in step S700, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in a plurality of sandstone samples of the first grain size are multiplied by 100 to obtain the corrected contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers.

[0053] In some embodiments, step S30 may further include the following steps: S31, compressing multiple sandstone samples of the first grain size into multiple compressed samples; S32, repeatedly measuring the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple compressed samples, and taking the average value of the multiple repeated measurements as the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples of the first grain size. In this embodiment, compressing the sandstone sample of the first grain size into a pellet sample can reduce the voids in the sample, ensure measurement accuracy, and facilitate accurate measurement of the content. This improves the accuracy of the measured contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers. Furthermore, performing multiple repeated measurements on the pellet sample and taking the average of the multiple repeated measurements as the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple sandstone samples of the first grain size can avoid random errors during measurement and also improve the accuracy of the measured contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers.

[0054] In some embodiments, in step S31, a tablet press can be used to compress multiple sandstone samples of the first particle size into multiple tablet samples. Specifically, the pressure of the tablet press can be set to a maximum of 20 tons, with constant pressure compression for 1 minute.

[0055] In the embodiments of this application, by pressing sandstone samples of the first particle size into pellet samples under constant pressure, it is beneficial to ensure that the internal structure of the pressed pellet samples is uniform, and it is beneficial to accurately measure the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers.

[0056] In some embodiments, in step S32, X-rays can be used to measure the content of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixtures, and illite / montmorillonite mixtures in the compressed sample. Specifically, the X-ray tube voltage can be set to a maximum value of 50 kV, the current can be set to a maximum value of 100 mA, and the detection time can be set to 30 seconds.

[0057] In some embodiments, in step S32, each compressed sample may be measured 3 to 10 times, and the average value of the 3 to 10 measurements may be taken as the content of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the sandstone sample of the first grain size. For example, each compressed sample may be measured 5 times.

[0058] In some embodiments, prior to step S31, the process may further include: S300, pre-treating multiple sandstone samples of a first particle size with H2O2 or dilute acetic acid, and extracting clay particles with a particle size less than 2 μm using sedimentation or centrifugation. In step S31, the clay particles extracted in step S300 are compressed into tablet samples. In this embodiment, multiple sandstone samples of the first particle size are treated with H2O2 or dilute acetic acid, which transforms the sandstone samples of the first particle size into clay particles, facilitating the subsequent extraction of clay particles with a particle size of less than 2 μm. Simultaneously, treating multiple sandstone samples of the first particle size with H2O2 or dilute acetic acid avoids the added reagents affecting the illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the sandstone samples of the first particle size. This facilitates accurate measurement of the contents of these elements in the sandstone samples of the first particle size. Furthermore, the extraction of clay particles with a particle size of less than 2 μm makes it easier to compress the clay particles into pellet samples in step S31.

[0059] In some embodiments, step S40 may further include the following steps: S41, purifying multiple sandstone samples of the second particle size to remove calcite from the samples; S42, digesting the purified sandstone samples of the second particle size; S43, determining the contents of SiO2, K2O, Na2O, CaO, and Al2O3 in the digested sandstone samples of the second particle size. In such embodiments, purifying the multiple sandstone samples of the second particle size can remove calcite crystals from the samples, avoiding the influence of calcite crystals on the measurement of SiO2, K2O, Na2O, CaO, and Al2O3 contents; simultaneously, digesting the pretreated sandstone samples of the second particle size allows for the measurement of SiO2, K2O, Na2O, CaO, and Al2O3 contents.

[0060] In some embodiments, in step S41, dilute hydrochloric acid can be used to purify multiple sandstone samples of the second particle size. In such embodiments, pretreatment of multiple sandstone samples of the second particle size with dilute hydrochloric acid can remove calcite crystals from the samples and avoid affecting the measurement of SiO2, K2O, Na2O, CaO, and Al2O3 content in the samples, thus ensuring the accuracy of the measured SiO2, K2O, Na2O, CaO, and Al2O3 content.

[0061] In some embodiments, in step S42, multiple sandstone samples of the second particle size are digested and purified using a mixed acid HNO3-HF-HClO4. In such embodiments, digesting and purifying the multiple sandstone samples of the second particle size using a mixed acid HNO3-HF-HClO4 ensures the high purity of the reagents used for digestion, avoids the introduction of impurities during the digestion process, and thus avoids affecting the accuracy of the measured SiO2, K2O, Na2O, CaO, and Al2O3 contents.

[0062] In some embodiments, step S50 may further include: determining that the CaO content is greater than the Na2O content, and determining the chemical weathering index of multiple sandstone samples with second particle size based on the K2O content, Na2O content, and Al2O3 content. During the digestion process, CaO and Na2O can interfere with each other, leading to inaccurate measurements of either the CaO or Na2O content. In the embodiments of this application, by determining that the CaO content is greater than the Na2O content and determining the chemical weathering index based on the K2O content, Na2O content, and Al2O3 content, the influence of inaccurately measured CaO content on the determined chemical weathering index can be avoided, thus ensuring the accuracy of the determined chemical weathering index.

[0063] In some embodiments, the chemical weathering index, K2O content, Na2O content, and Al2O3 content of multiple second-grained sandstone samples conform to the following relationship:

[0064] Z=2×Al2O3 / (Al2O3+2Na2O+K2O)×100,

[0065] In the formula, Z represents the chemical weathering index of multiple sandstone samples with second grain size, Al2O3 represents the Al2O3 content, Na2O represents the Na2O content, and K2O represents the K2O content. In this embodiment, the chemical weathering index of multiple sandstone samples with second grain size can be accurately determined according to the above relationship.

[0066] In other embodiments, step S50 may further include: determining that the CaO content is less than or equal to the Na2O content, and determining the chemical weathering index of multiple sandstone samples with second particle size based on the K2O content, Na2O content, CaO content, and Al2O3 content. During the digestion process, CaO and Na2O can interfere with each other, leading to inaccurate measurements of the CaO or Na2O content. In the embodiments of this application, by determining that the CaO content is less than or equal to the Na2O content, and determining the chemical weathering index based on the K2O content, Na2O content, CaO content, and Al2O3 content, the influence on the determined chemical weathering index can be avoided, thus ensuring the accuracy of the determined chemical weathering index.

[0067] In some embodiments, the chemical weathering index, K2O content, Na2O content, and Al2O3 content of multiple second-grained sandstone samples conform to the following relationship:

[0068] Z=2×Al2O3 / (Al2O3+CaO+Na2O+K2O)×100,

[0069] In the formula, Z represents the chemical weathering index of multiple sandstone samples with second grain size, Al2O3 represents the Al2O3 content, CaO represents the CaO content, Na2O represents the Na2O content, and K2O represents the K2O content. In this embodiment, the chemical weathering index of multiple sandstone samples with second grain size can be accurately determined according to the above relationship.

[0070] The process of determining the sandstone deposit using the method provided in the embodiments of this application is described below. A total of 21 samples from known deposits were collected, all of which were Cretaceous sandstone samples. These 21 samples came from the Songliao Basin, Erlian Basin, Ordos Basin, and Junggar Basin, respectively. Specifically, there were 5 samples from the Songliao Basin, 4 samples from the Erlian Basin, 8 samples from the Ordos Basin, and 4 samples from the Junggar Basin.

[0071] (1) First, the above 21 samples were made into 21 70-mesh samples and 21 200-mesh samples respectively according to 70-mesh and 200-mesh; then, the 21 70-mesh samples were treated with dilute acetic acid and clay particles with a particle size of less than 2μm were extracted after treatment; then, the clay particles were pressed into 21 tablet samples by pressing them under a pressure of 20 tons for 1 minute using a tablet press.

[0072] (2) Then, the X-ray tube voltage was set to the maximum value of 50kV, the current was set to the maximum value of 100mA, and the detection time was set to 30 seconds. The contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer and illite / montmorillonite mixed layer in 21 compressed samples were measured using X-rays emitted by the X-ray tube. Each compressed sample was measured 5 times, and the average value of the 5 measurements was taken as the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer and illite / montmorillonite mixed layer in each 70-mesh sample.

[0073] (3) The 21 samples of 200 mesh were pretreated with dilute hydrochloric acid. After the pretreatment was completed, the 21 samples of 200 mesh were digested with HNO3-HF-HClO4. The contents of SiO2, K2O, Na2O, CaO and Al2O3 in the 21 samples of 200 mesh were measured. Then, based on the measured contents of SiO2, K2O, Na2O, CaO and Al2O3 in the 21 samples of 200 mesh, the chemical weathering index and the ratio of SiO2 content to Al2O3 content of each 200 mesh sample were determined.

[0074] Referring to Table 1 below, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in 21 70-mesh samples, as well as the chemical weathering index X of 21 200-mesh samples and the ratio of SiO2 content to Al2O3 content of 21 200-mesh samples are shown in Table 1 below.

[0075] Table 1. Contents of the above-mentioned substances, chemical weathering index, and ratio of SiO2 content to Al2O3 content in 21 samples.

[0076]

[0077]

[0078] (4) Multiply the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in the 21 70-mesh samples by 100 for correction; then, determine the intermediate matrix ∑ based on the chemical weathering index of the 21 200-mesh samples and the corrected contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in the 21 70-mesh samples, as well as the ratio of SiO2 content to Al2O3 content in the 21 200-mesh samples.

[0079] Referring to Table 2 below, the elements in the determined intermediate matrix ∑ are shown in Table 2.

[0080] The elements in the intermediate matrix ∑ determined in Table 2

[0081]

[0082] (5) Based on the above intermediate matrix, eight eigenvalues ​​are calculated; then the contribution rate of these eight eigenvalues ​​and the sum of their contribution rates (also known as the cumulative contribution rate) are calculated.

[0083] Referring to Table 3 below, the calculated 8 eigenvalues, the contribution rate of the 8 eigenvalues, and the cumulative contribution rate of the 8 eigenvalues ​​are shown in Table 3.

[0084] Table 3 shows the determined eigenvalues, their contribution rates, and cumulative contribution rates.

[0085] 1 1420.314 71.691 71.691 2 425.752 21.490 93.181 3 77.204 3.897 97.078 4 40.842 2.061 99.139 5 11.197 0.565 99.705 6 4.714 0.238 99.942 7 1.134 0.057 100.000 8 0.006 0.000 100.000

[0086] As shown in Table 3, the first seven eigenvalues ​​are all greater than 1. Among them, the first eigenvalue λ1 reaches 1420.314, with a contribution rate of 71.691%; the second eigenvalue λ2 is 425.752, with a contribution rate of 93.181%; and the third eigenvalue λ3 is 77.204, with a contribution rate of 97.078%. The cumulative contribution rate of the first two eigenvalues ​​has reached 93.181%, which is greater than the preset contribution rate value of 80%. Therefore, the first and second classification functions related to the sandstone's origin are determined based on the first two eigenvalues.

[0087] Refer to Table 4 below. The coefficients of each item in the first classification function and the second classification function determined based on the first two feature values ​​are shown in Table 4.

[0088] Table 4 shows the coefficients of each item in the classification function.

[0089] illite -0.120 0.313 chlorite -0.086 0.285 Montmorillonite 0.096 -0.048 Kaolinite -0.003 -0.010 Chlorite / montmorillonite mixed layer 0.524 -0.437 illite / montmorillonite mixed layer -0.430 -0.691 X -0.003 0.003 <![CDATA[SiO2 / Al2O3]]> 0.032 -0.022

[0090] Based on the coefficients in Table 4 above, the first classification function and the second classification function are determined as follows:

[0091] Y1=-0.12×Ill-0.086×Chl+0.096×Mnt-0.003×Kln+0.524×CM-

[0092] 0.43×IM-0.003×X+0.032×SiO2 / Al2O3,

[0093] Y2=0.313×Ill+0.285×Chl-0.048×Mnt-0.01×Kln-0.437×CM-

[0094] 0.691×IM+0.003×X-0.022×SiO2 / Al2O3,

[0095] Wherein, Y1 and Y2 are the first and second classification function values, Ill is the illite content, Chl is the chlorite content, Mnt is the montmorillonite content, Kln is the kaolinite content, CM is the chlorite / montmorillonite mixed layer content, IM is the illite / montmorillonite mixed layer content, X is the chemical weathering index, and SiO2 / Al2O3 is the ratio of SiO2 content to Al2O3 content.

[0096] (6) Using the first classification function as the x-axis and the second classification function as the y-axis, the relationship between the 21 samples and the first and second classification functions is shown in the following graph. Figure 2 , Figure 2 It is based on Figure 1 The diagram shows the relationship between multiple control samples and multiple classification functions determined by the method. From Figure 2 The distribution of 21 sandstone samples from different geographical sources shows a relatively obvious clustering phenomenon, mainly divided into four categories: Category 1 sample 21 is from the Songliao Basin, Category 2 sample 22 is from the Erlian Basin, Category 3 sample 23 is from the Ordos Basin, and Category 4 sample 24 is from the Junggar Basin. Category 1 samples 21 and Category 3 samples 23 show good clustering, making their distribution patterns easy to determine; Category 2 samples 22 and Category 4 samples 24 show relatively good clustering with small spacing between them, also allowing for the determination of their distribution patterns.

[0097] (7) Based on the chemical weathering index of multiple sandstone samples, the ratio of SiO2 content to Al2O3 content of multiple sandstone samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in multiple sandstone samples, as well as the first classification function and the second classification function mentioned above, determine the first classification function value Y1 and the second classification function value Y2 corresponding to each sandstone sample; S82. Based on the first classification function value Y1 and the second classification function value Y2 corresponding to each sandstone sample, determine the contents of each sandstone sample in... Figure 2 The location in; S83, according to each sandstone sample in Figure 2 Based on the location of the samples and the distribution patterns of the four types of samples mentioned above, the origins of multiple sandstone samples whose origins are to be determined can be identified.

[0098] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0099] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A method for determining the origin of sandstone, characterized in that, The method includes: S10. Obtain multiple sandstone samples from locations to be determined; S20. The multiple sandstone samples are made into multiple sandstone samples with a first particle size and multiple sandstone samples with a second particle size, wherein the first particle size is larger than the second particle size. S30. Determine the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the plurality of sandstone samples of the first grain size; S40. Determine the contents of SiO2, K2O, Na2O, CaO and Al2O3 in the plurality of second-size sandstone samples; S50. Based on the SiO2, K2O, Na2O, CaO and Al2O3 contents in the plurality of second-grain size sandstone samples determined in step S40, determine the chemical weathering index and the ratio of SiO2 content to Al2O3 content of the plurality of second-grain size sandstone samples. S60. Obtain multiple control samples with known origins, and perform steps S20-S50 on the multiple control samples; S70. Based on the origin of the multiple reference samples, the chemical weathering index of the multiple reference samples, the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple reference samples, and the ratio of SiO2 content to Al2O3 content in the multiple reference samples, determine the origin distribution pattern of the multiple reference samples. S80. Based on the chemical weathering index of the multiple sandstone samples, the ratio of SiO2 content to Al2O3 content of the multiple sandstone samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples, as well as the site distribution pattern determined in step S70, determine the site of the multiple sandstone samples whose site is to be determined. Step S70 also includes the following steps: S71. Based on the chemical weathering index of the multiple reference samples and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple reference samples, as well as the ratio of SiO2 content to Al2O3 content in the multiple reference samples, determine multiple characteristic values ​​related to the origin of the reference samples. S72. Based on the plurality of feature values, determine the contribution rate of each feature value in determining the place of origin; S73. Based on the contribution rate of each of the feature values ​​in determining the place of origin, determine a plurality of feature values ​​whose sum of contribution rates is greater than a preset contribution rate value; S74. Based on the multiple characteristic values ​​determined in step S73, the chemical weathering index of the multiple control samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, as well as the ratio of SiO2 content to Al2O3 content in the multiple control samples, determine multiple classification functions related to the origin of sandstone. S75. Based on the multiple classification functions determined in step S74, the chemical weathering index of the multiple control samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, as well as the ratio of SiO2 content to Al2O3 content in the multiple control samples, determine the geographical distribution pattern of the multiple control samples. Step S75 also includes the following steps: S751. Based on the multiple classification functions determined in step S74, the chemical weathering index of each control sample, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in each control sample, as well as the ratio of SiO2 content to Al2O3 content in each control sample, determine the multiple classification function values ​​corresponding to each control sample. S752. Determine the relationship between the plurality of control samples and the plurality of classification functions; S753. Determine the position of each control sample in the relationship graph based on the multiple classification function values ​​corresponding to each control sample; S754. Based on the positions of the multiple control samples in the relationship diagram and the origin of each control sample, determine the origin distribution pattern of the multiple control samples; The S80 step also includes the following steps: S81. Based on the chemical weathering index of the multiple sandstone samples, the ratio of SiO2 content to Al2O3 content of the multiple sandstone samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in the multiple sandstone samples, as well as the multiple classification functions determined in step S74, determine the multiple classification function values ​​corresponding to each sandstone sample. S82. Determine the position of each sandstone sample in the relationship diagram based on the multiple classification function values ​​corresponding to each sandstone sample; S83. Based on the position of each sandstone sample in the relationship diagram and the distribution pattern of the multiple control samples, determine the origin of the multiple sandstone samples whose origin is to be determined.

2. The method according to claim 1, characterized in that, Step S74 also includes the following steps: S741. Determine that multiple classification functions related to the sandstone's origin conform to the following relationship: ， In the formula, Let a, b, e, and d be the classification function values ​​related to the sandstone's origin, and a, b, e, and d be the parameters. The content of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the control sample or the sandstone sample. The chemical weathering index of the control sample or the sandstone sample. The ratio of SiO2 content to Al2O3 content in the control sample or the sandstone sample; S742. Based on the multiple characteristic values ​​determined in step S73, the chemical weathering index of the multiple control samples, and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple control samples, as well as the ratio of SiO2 content to Al2O3 content in the multiple control samples, determine a, b, e, and d.

3. The method according to claim 1, characterized in that, Step S71 also includes the following steps: S711. Determine the mean value of the chemical weathering index of the multiple control samples based on the chemical weathering index of the multiple control samples. S712. Based on the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in the multiple reference samples, determine the average contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in the multiple reference samples. S713. Determine the average value of the ratio of SiO2 content to Al2O3 content of the multiple control samples based on the ratio of SiO2 content to Al2O3 content of the multiple control samples. S714. Based on the mean value determined in step S711 and the chemical weathering index of each control sample, determine the difference between the chemical weathering index of each control sample and the mean value determined in step S711. S715. Based on the mean value determined in step S712 and the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in each of the control samples, determine the difference between the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layer, and illite / montmorillonite mixed layer in each of the control samples and the mean value determined in step S712. S716. Based on the mean value determined in step S713 and the ratio of SiO2 content to Al2O3 content of each control sample, determine the difference between the ratio of SiO2 content to Al2O3 content of each control sample and the mean value determined in step S713. S717. Based on the difference determined in step S714, step S715, and step S716, determine the plurality of characteristic values ​​related to the origin of the control sample.

4. The method according to claim 1, characterized in that, Step S30 also includes the following steps: S31. The plurality of sandstone samples of the first particle size are compressed into a plurality of compressed samples; S32. The contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple pressed samples are measured repeatedly, and the average value of the multiple repeated measurements is taken as the contents of illite, montmorillonite, chlorite, kaolinite, chlorite / montmorillonite mixed layers, and illite / montmorillonite mixed layers in the multiple sandstone samples of the first grain size.

5. The method according to claim 1, characterized in that, Step S40 also includes the following steps: S41. The plurality of second-size sandstone samples are purified to remove calcite from the plurality of second-size sandstone samples. S42. The plurality of second-size sandstone samples after digestion and purification treatment; S43. Determine the contents of SiO2, K2O, Na2O, CaO and Al2O3 in the plurality of second-size sandstone samples after digestion.

6. The method according to claim 5, characterized in that, In step S41, the plurality of second-size sandstone samples are purified using dilute hydrochloric acid.

7. The method according to claim 5, characterized in that, In step S42, the multiple second-size sandstone samples were digested and purified using a mixed acid HNO3-HF-HClO4.

8. The method according to claim 1, characterized in that, Step S50 also includes: The CaO content was determined to be greater than the Na2O content. Based on the K2O content, Na2O content, and Al2O3 content, the chemical weathering index of the multiple second-grain-size sandstone samples was determined.

9. The method according to claim 1, characterized in that, Step S50 also includes: The CaO content was determined to be less than or equal to the Na2O content. Based on the K2O content, Na2O content, CaO content, and Al2O3 content, the chemical weathering index of the plurality of second-grain-size sandstone samples was determined.

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