A uranium-lead isotope t-w dating method, system, device and medium

Abstract

The application discloses a uranium-lead isotope T-W dating method, system, device and medium, relates to the technical field of isotope geology, and comprises the following steps: obtaining initial U-Pb isotope values of a sample; performing multi-stage geological evolution based on the initial U-Pb isotope values, determining a lead isotope ratio range of the sample, and the lead isotope ratio range representing a value range of an intersection point of a T-W inconsistent line and a T-W anti-inconsistent line of the sample; limiting T-W dating application conditions of the sample based on the lead isotope ratio range, and obtaining age data of the sample. Through the method, the isotope dating has geological significance, and therefore the dating reliability is improved.

Description

Technical Field

[0001] This application relates to the field of isotope geology, and in particular to a method, system, equipment and medium for TW dating of uranium-lead isotopes. Background Technology

[0002] The TW dating method is a uranium-lead isotope dating method for lunar samples, developed and refined in 1972 by Fouad Tera and G.J. Wasserburg. Subsequently, in 1997, G.J. Wasserburg further developed the method and initially proposed its applicable conditions and applicable rock and mineral types. In recent years, with the widespread application of micro-area in-situ measurement technology, this method is particularly suitable for directly measurable... 207 Pb / 206 Pb and 238 U / 206 Pb ratios are used for uranium-lead dating of samples. However, due to the vague definition of the conditions for using this dating method by previous researchers, many age results obtained by this method are geologically meaningless, even though some ages have characteristics such as: 1) reasonable mathematical fitting parameters; 2) the TW intersection age is consistent with the weighted average age after ordinary lead subtraction, etc. The age results are still geologically meaningless, resulting in dating that is not geologically meaningful and has low reliability. Summary of the Invention

[0003] To overcome the problem that the age results obtained by existing TW dating methods are geologically meaningless, resulting in dating without geological significance and low reliability, this application provides a uranium-lead isotope TW dating method, system, equipment and medium.

[0004] Firstly, in order to solve the above-mentioned technical problems, this application provides a uranium-lead isotope TW dating method, comprising: Obtain the initial U-Pb isotope values ​​of the sample; Based on the initial U-Pb isotope values, multi-stage geological evolution was carried out to determine the range of lead isotope ratio values ​​of the sample. The range of lead isotope ratio values ​​characterizes the range of values ​​of the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The TW dating conditions for the samples were limited by the lead isotope ratio range, and the age data of the samples were obtained.

[0005] Secondly, this application also provides a uranium-lead isotope TW dating system, comprising: The acquisition module is used to acquire the initial U-Pb isotope values ​​of the sample; The multi-stage geological evolution module is used to perform multi-stage geological evolution based on the initial U-Pb isotope values, determine the lead isotope ratio range of the sample, and the lead isotope ratio range characterizes the range of values ​​of the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The TW dating module is used to define the applicable conditions for TW dating of samples based on the lead isotope ratio range, and to obtain the age data of the samples.

[0006] Thirdly, this application also provides a computing device, including a memory, a processor, and a program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of the uranium-lead isotope TW dating method as described above.

[0007] Fourthly, this application also provides a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the steps of the aforementioned uranium-lead isotope TW dating method.

[0008] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the uranium-lead isotope TW dating method as described above.

[0009] The beneficial effects of this application are as follows: Based on the initial U-Pb isotope values ​​of the sample, multi-stage geological evolution is performed to determine the range of lead isotope ratios of the sample. This range characterizes the range of values ​​at the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. Furthermore, the applicable conditions for TW dating of the sample are limited based on the lead isotope ratio range, thereby constraining the age results of the sample and obtaining a reliable age. In this way, through precise calculation of the multi-stage evolution of uranium-lead isotopes in the sample, and then performing TW dating based on the evolution results, the uranium-lead isotope dating of the sample can be geologically significant, thus improving the reliability of sample dating. Attached Figure Description

[0010] Figure 1 This is a flowchart illustrating a TW dating method for uranium-lead isotopes, as shown in an exemplary embodiment of this application. Figure 2 This is a schematic flowchart illustrating the application of the provided uranium-lead isotope TW dating method in an exemplary embodiment of this application. Figure 3 This is a comparison diagram of the uranium-lead isotope TW method results of a sample in an exemplary embodiment of this application; Figure 4 This is a schematic diagram of the structure of a uranium-lead isotope TW dating system, which is an exemplary embodiment of this application. Detailed Implementation

[0011] The following embodiments are further explanations and supplements to this application and do not constitute any limitation on this application.

[0012] The following describes, with reference to the accompanying drawings, a method, system, apparatus, and medium for TW dating of uranium-lead isotopes according to embodiments of this application.

[0013] This application belongs to the field of isotope geology theory, and also to the field of uranium-lead isotope theory and application. Therefore, it can be applied to basic geology and other related fields. Specifically, it involves technical methods for determining the applicability of whole-rock and single-mineral U-Pb isotope Tera-Wasserburg dating (TW method) and establishes the preconditions for the applicability of the TW dating method.

[0014] Clearly, the paradox of a reasonable mathematical fit and the fact that age has no geological significance is actually due to the fact that the U-Pb system is open and cannot be calculated using isotopic methods.

[0015] In response to this phenomenon, this application, based on a detailed study and analysis of the fundamental theory of uranium-lead isotopes and the TW method, and combined with a reanalysis of TW age data from a large number of published articles, proposes several basic conditions for determining the applicability of TW isotopic age using this method. It also establishes a set of calculation methods and geological interpretation methods based on the U-Pb single-three-stage model for determining the preconditions for TW isotopic age applicability.

[0016] This application mainly concerns the applicable preconditions and geological significance of TW method calculations for uranium-lead isotope ages using whole-rock, single-mineral TIMS, and micro-area in-situ methods. Based on the U-Pb isotope multi-stage model, the intersection value of the TW inconsistency line with the Y-axis is calculated, i.e., the original lead (common lead). 207 Pb / 206 The Pb value is used as a prerequisite for TW age calculation. For Earth samples, calculations are performed based on a single- to multi-stage U-Pb isotope system. 207 Pb / 206 The Pb ratio, which is the intersection of the TW inconsistency line and the Y-axis, represents the initial common lead isotope ratio of the U-Pb system as it has evolved to the present. It is the evolution value of the U-Pb isotope closed system and is the basis for isotope age calculation. A value within this range indicates that the isotopes are in a closed system, which is why they can be used for isotope age calculation. This is the core of using isotopes for geological body age calculation.

[0017] The method provided in this application specifies the preconditions for its use, fundamentally avoiding the problem mentioned above that while the TW method is mathematically feasible, it is geologically meaningless. Furthermore, the method provided in this application has been applied to isotopic TW age calculations for various rocks, ores, and single minerals, limiting the preconditions for U-Pb isotopic dating methods and improving the reliability of these ages.

[0018] The method provided in this application is based on the U-Pb single-stage to three-stage theory and employs appropriate mathematical methods to obtain the common lead isotope ratios at different stages. These values ​​conform to the U-Pb isotope evolution theory and have good reliability. Furthermore, the method provided in this application is suitable for TW isotope dating, and has been analyzed and validated against publicly published TW age results, achieving the desired effect.

[0019] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0020] The uranium-lead isotope TW dating method provided in this application can be executed by a server. It should be noted that the server can be a standalone server or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. No limitation is imposed here.

[0021] Please see Figure 1 , Figure 1 A uranium-lead isotope TW dating method is illustrated in an exemplary embodiment of this application, such as... Figure 1 As shown, this application provides a TW dating method for uranium-lead isotopes, comprising: S101, Obtain the initial U-Pb isotope values ​​of the sample; S102, based on the initial U-Pb isotope multi-stage geological evolution, the lead isotope ratio range of the sample is determined. The lead isotope ratio range characterizes the range of values ​​of the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. S103, based on the lead isotope ratio range to limit the applicable conditions for TW dating of the sample, the age data of the sample was obtained.

[0022] The uranium-lead isotope TW dating method provided in this application performs multi-stage geological evolution based on the initial U-Pb isotope values ​​of the sample to determine the range of lead isotope ratios. This range characterizes the range of intersections between the sample's TW inconsistencies and anti-TW concordance lines. The applicable conditions for TW dating are limited based on this lead isotope ratio range, thus constraining the sample's age results and yielding a reliable age. In this way, by accurately calculating the multi-stage evolution of the sample's uranium-lead isotopes and then performing TW dating based on the evolution results, the uranium-lead isotope dating of the sample gains geological significance, thereby improving the reliability of sample dating.

[0023] In an exemplary embodiment provided in this application, the U-Pb isotopic systems of Earth's geological bodies have all evolved since the formation of the Earth, beginning with an isotopic homogenization system at the beginning of formation, that is, since 4570 Ma, based on the initial U-Pb isotopic values. 238 U / 204 Pb=9.26 235 U / 204 Pb=9.26 / 137.88 206 Pb / 204 Pb0=9.308 207 Pb / 204 Pb0=10.294 has evolved to the present day.

[0024] The initial parameter values ​​varied slightly in previous studies using different models, but these differences do not affect the results of this application. Based on the U-Pb isotope evolution model, calculations can be performed from the formation of the Earth to the present day. 206 Pb / 204 Pb, 207 Pb / 204 Pb and 207 Pb / 206 The Pb ratio represents the possible range of values ​​for the calculated object during geological history. The parameters used in the calculation are those given in the literature "Xia Yuliang. 2019. Geochronology of Uranium Metallogenic Geology in China [M]. Beijing: China Atomic Energy Press, 1-301".

[0025] Optionally, based on the initial U-Pb isotope values, multi-stage geological evolution is performed to determine the range of lead isotope ratios in the sample, including: Based on the initial U-Pb isotope values, a single-stage geological evolution was performed to obtain the single-stage lead isotope ratio of the sample. Two-stage geological evolution was performed based on the initial U-Pb isotope values ​​to obtain the two-stage lead isotope ratios of the sample. Based on the initial U-Pb isotope values, a three-stage geological evolution was performed to obtain the three-stage lead isotope ratios of the sample. Based on single-stage, two-stage, and three-stage lead isotope ratios, a range of lead isotope ratios for the sample is formed.

[0026] In the embodiment provided in this application, single-stage, two-stage, and three-stage geological evolution are performed based on the initial U-Pb isotope values ​​to obtain the lead isotope ratios for the corresponding stages, forming a range of lead isotope ratios for the sample. This facilitates subsequent TW dating of the lead isotope ratio range of the geological evolution, making the sample isotope dating geologically significant and thus improving the reliability of sample dating.

[0027] In an exemplary embodiment provided in this application, the TW method preconditions and the geological significance of the I value are as follows: The lead isotope ratio I calculated based on the initial U-Pb isotope values ​​in different models (single-stage geological evolution, two-stage geological evolution, and three-stage geological evolution) reflects the following geological significance: From the formation of the Earth to the present, the U-Pb isotopes of the Earth's geological bodies have undergone 1 to 3 isotopic system openings (t0, t1, t2), and finally remained closed and evolved to the present state. 207 Pb / 204 Pb value, 206 Pb / 204 The Pb value, and the calculations derived from it. 207 Pb / 206 The Pb value (I), based on subsequent examples, shows a main variation range between 0.83 and 0.899, which can represent the evolution of most Earth samples. Therefore, 207 Pb / 206 The range of Pb = 0.83~0.899 can be used as the range of lead isotope ratios of the sample (that is, the range of values ​​of the intersection of the TW inconsistency line and the TW anticonsistency line of the sample), which limits the prerequisite for subsequent evolution dating by the TW method.

[0028] Optionally, the sample is a lead isotope standard of the Earth; Based on the initial U-Pb isotope values, a single-stage geological evolution was performed to obtain the single-stage lead isotope ratios of the samples. The corresponding evolution formula is as follows: I1=( 207 Pb / 204 Pb)1 / ( 206 Pb / 204 Pb)1 ( 206 Pb / 204 Pb)1= 206 Pb / 204 Pb0+ 238 U / 204 Pb(e λ8t0 -1) (207 Pb / 204 Pb)1= 207 Pb / 204 Pb0+ 238 U / 204 Pb×137.88 (e λ8t0 -1) Wherein, I1 represents the single-stage lead isotope ratio. 238 U / 204 Pb is the initial U-Pb isotopic value. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, where t0 is the formation age of the Earth.

[0029] In the embodiment provided in this application, a single-stage geological evolution is performed based on the initial U-Pb isotope value to obtain the single-stage lead isotope ratio of the sample. This facilitates subsequent TW dating of the lead isotope ratio range formed by the geological evolution based on the lead isotope ratio, making the sample isotope dating geologically significant and thereby improving the reliability of sample dating.

[0030] In one exemplary embodiment provided in this application, a single-stage geological evolution model of U-Pb is presented: lead isotopes from the formation of the Earth to the present are calculated based on a single-stage U-Pb isotope model. 207 Pb / 204 Pb value, 206 Pb / 204 Pb value, 207 Pb / 206 Pb value.

[0031] In the formula for the evolution of lead isotope ratios in a single stage, λ8 is... 238 The variable constant U is specifically 0.155125 × 10⁻⁶. -9 a -1 ; 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 is the Pb isotope value from the Earth's formation to the present day, from which the following calculations were performed. 206 Pb / 204 Pb and 207 Pb / 204 Given the current value of Pb, I1 = 0.862977 ≈ 0.863. This value represents the terrestrial evolution value of lead isotopes, reflecting the values ​​of isotopic systems in geological bodies on Earth that have evolved in a closed manner since the initial homogenization of the Earth.

[0032] Optionally, the sample is a lead isotope standard of the Earth; Based on the initial U-Pb isotope values, a two-stage geological evolution was performed to obtain the two-stage lead isotope ratios of the sample. The corresponding evolution formula is as follows: I2 = ( 207 Pb / 206 Pb) SK =( 207 Pb / 204 Pb)2 / ( 206 Pb / 204 Pb)2 ( 206 Pb / 204 Pb)2= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 -1) ( 207 Pb / 204 Pb)2= 207 Pb / 204 Pb0+ 238 U / ( 204 Pb×137.88)0×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 -1) Wherein, I2 represents the two-stage lead isotope ratio in the SK mode. 238 U / 204 Pb is the initial U-Pb isotopic value, specifically 9.26. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, and t1 is the crust-mantle differentiation age of the Earth, specifically 3.7 Ga. 238 U / 204 Pb)1 is the value that evolved from the crust-mantle differentiation at 3.7 Ga to the present. 238 U / ( 204 Pb × 137.88)0 represents the Earth's evolution from its formation to the present day. 235 U / 204 Pb value, specifically 238 U / (204 Pb×137.88)0=9.26 / 137.88,λ5 is 235 The decay constant of U, 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 The Pb value is specifically ( 235 U / 204 Pb)1 value, in Excel use the Isoplot add-in and input age (t0=4.57Ga, t1=3.7Ga), initial 238 U / 204 Pb=9.26, 207 Pb / 204 Pb0 = 10.294 was calculated.

[0033] In the embodiment provided in this application, a two-stage geological evolution is performed based on the initial U-Pb isotope value to obtain the two-stage lead isotope ratio of the sample. This facilitates subsequent TW dating of the lead isotope ratio range formed by the two-stage lead isotope ratio of the geological evolution, making the sample isotope dating geologically significant and thereby improving the reliability of sample dating.

[0034] In this embodiment, in the evolution formula corresponding to the two-stage lead isotope ratios, λ8 and λ5 are respectively 238 U and 238 The decay constants of U are 0.155125 × 10⁻⁶. -9 a -1 0.98485×10 -9 a -1 t0=4570Ma, t1=3700Ma 238 U / 204 Pb=7.19, 238 U / 204 Pb1=9.74, and other parameters are the same as those in the evolution formula for single-stage lead isotope ratios. The final calculation yields ( 207 Pb / 206 Pb) SK =0.83562≈0.835.

[0035] In one exemplary embodiment provided in this application, the two-stage geological evolution model (SK model) is based on the document "Stacey, JS, Kramers, JD, 1975. Approximation of Terrestrial Lead-Isotope Evolution By a Two..." The Stage Model, proposed in *Earth and Planetary Science Letters*, 26(2): 207–221, describes a two-stage evolution of the Earth after its formation, following crust-mantle differentiation over 3700 Ma. This model calculates... 207 Pb / 206 Pb values ​​represent the values ​​of geological bodies on Earth after the initial homogenization of the Earth, when the isotopic system closed and evolved to the crust-mantle differentiation event at 3700 Ma, during which the isotopic system briefly opened, then closed again and evolved to its current value.

[0036] The SK mode is equivalent to a special U-Pb two-stage mode, yielding... 207 Pb / 206 The Pb value (I2) differs slightly from the single-stage geological evolution value of U-Pb (I1), with a relative error of <5%.

[0037] Optionally, the sample is a lead isotope standard of the Earth; Based on the initial U-Pb isotope values, a three-stage geological evolution was performed to obtain the three-stage lead isotope ratios of the sample. The corresponding evolution formula is as follows: I3 = ( 207 Pb / 204 Pb)3 / ( 206 Pb / 204 Pb)3 ( 206 Pb / 204 Pb)3= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 - e λ8t2 ) +( 238 U / 204 Pb)2×(e λ8t2 -1) ( 207 Pb / 204 Pb)3= 207 Pb / 204 Pb0+ 235 U / 204 Pb×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 - e λ5t2)+ 238 U / ( 204 Pb×137.88)1×(e λ5t2 -1) Wherein, I3 represents the three-stage lead isotope ratio. 238 U / 204 Pb and 235 U / 204 All Pb values ​​are initial U-Pb isotopic values. Specifically... 238 U / 204 Pb=9.26, 235 U / 204 Pb=9.26 / 137.88; 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, and t1 is the crust-mantle differentiation age of the Earth, specifically 3.7 Ga. 238 U / 204 Pb)1 is the value of crust-mantle differentiation and evolution from 3.7 Ga to the present, and t2 is the geological formation time of the sample. 238 U / 204 Pb)2 represents the value of the sample since its formation and evolution from the geological body to the present day, i.e., the currently measured value; λ5 represents... 235 The decay constant of U; 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 The Pb value is equal to ( 235 U / 204 Pb) 1, the value is (given) 238 U / 204 Pb1) / 137.88, in Excel, use the Isoplot add-in and input the age (t0=4.57Ga, t1=3.7Ga) and initial... 238 U / 204 Pb=9.26 207 Pb / 204 Pb0 = 10.294 was calculated.

[0038] In the embodiment provided in this application, the three-stage lead isotope ratio of the sample is obtained based on the three-stage evolution calculation results of U-Pb isotopes. This facilitates subsequent TW dating of the lead isotope ratio range formed by the three-stage lead isotope ratio of the geological evolution, making the sample isotope dating geologically significant and thus improving the reliability of sample dating.

[0039] In an exemplary embodiment provided in this application, the evolution formula corresponding to the three-stage lead isotope ratios is as follows: ( 206 Pb / 204 Pb)3, ( 207 Pb / 204 Pb)3 is the measured value; t0, 238 U / 204 Pb, 235 U / 204 The evolution formulas corresponding to the Pb, λ8, and λ5 is the same as those corresponding to the two-stage lead isotope ratios; 238 U / 204 Pb)1 was taken as 9.26 and 7.19 respectively; 238 U / 204 Pb)2 was taken as 9.0 and 10.0 respectively; 238 U / 204 Pb)2 is taken as 9.0, 10.0, and 10.27 respectively; t1 is taken as 3700 Ma, 3000 Ma, and 2500 Ma respectively; t2 is taken as 2500 Ma, 1800 Ma, 1000 Ma, 500 Ma, 300 Ma, and 100 Ma respectively.

[0040] The three-stage lead isotope ratios I3, calculated using the evolution formula corresponding to the three-stage lead isotope ratios, are shown in Table 1. Table 1 lists the calculated values ​​of the three-stage geological evolution model of U-Pb. 206 Pb / 204 Pb)3, ( 207 Pb / 204 Pb)3 and the ratio of the two.

[0041] Table 1

[0042] When calculating the data in Table 1, ( 238 U / 204 Pb)1, ( 238 U / 204 When Pb)2 is set to 9.0 and 9.67 respectively, the three-stage lead isotope ratio I3 obtained when these two parameters are set to 7.19 and 9.67 and 10.27 respectively changes from the corresponding age calculated values ​​in Table 1, and the change is the second decimal place.

[0043] Analogous to Table 1, t1, t2, ( 238 U / 204 Pb)1, ( 238 U / 204 The range of I values ​​calculated after matching different values ​​of parameters such as Pb)2 is 0.84~0.899.

[0044] Furthermore, by deriving the evolution formula corresponding to the three-stage lead isotope ratios, a multi-stage U-Pb evolution formula (more than three stages) was derived, and the calculated... 207 Pb / 206 The lowest Pb value can be 0.78, and the highest is no greater than 0.89.

[0045] Optionally, based on the lead isotope ratio range, the applicable conditions for TW dating of the sample are defined to obtain the sample's age data, including: Using the lead isotope ratio range as a precondition for the TW method, the initial lead that matches the lead isotope ratio range is matched from the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The TW method was used to date the samples based on the initial lead content using different evolution systems of uranium-lead isotopes, thus obtaining the sample age data.

[0046] In the embodiment provided in this application, the lead isotope ratio range is used as a prerequisite for the TW method. The initial lead that matches the lead isotope ratio range is matched from the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The sample is then dated using the TW method based on the initial lead in different evolution systems of uranium-lead isotopes. This combination of geology and dating can be achieved, so that the age data of the sample can have geological significance, thereby improving the reliability of sample dating.

[0047] In this embodiment, the TW method is the existing TW concordance method for calculating the chronology and common lead value of lunar samples. Therefore, the steps of dating the sample based on the initial lead using the TW method for different evolution systems of uranium-lead isotopes are consistent with the steps of calculating the chronology and common lead value of lunar samples using the existing TW concordance method.

[0048] Optionally, the basic formula for TW inconsistency is: I= 207 Pb / 206 Pb= 238 U / 206 U×(e) λ5t -1) / 137.88+I0 Where I is 207 Pb / 206 The test value of Pb, (e λ5t -1) / 137.88 is the slope, λ5 is 235 The decay constant of U, t is the geological formation time of the sample, and I0 is the initial lead isotope ratio. The TW anti-uniform line is derived from X=1 / (e λ8t -1), Y=(1 / 137.88)×(e λ5t -1) / (e λ8t The curve formed by -1).

[0049] In the embodiment provided in this application, the corresponding curves can be plotted by expressing the TW inconsistency line and the TW anticonsistency line of the sample, so as to intuitively obtain the intersection point between the curves. This makes it possible to match the initial lead that matches the lead isotope ratio range from the intersection point of the TW inconsistency line and the TW anticonsistency line of the sample, and to perform evolution dating of the initial lead by the TW method, thereby combining geological facts with isotope dating, making the sample isotope dating geologically significant, and thus improving the reliability of sample dating.

[0050] In this embodiment, in the basic formula for the TW inconsistency line, λ5 is 235 U is a variable constant; I and I0 are respectively 207 Pb / 206 The measured value of Pb, the isotopic ratio of the initial lead (ordinary lead); the slope m is (e λ5t -1) / 137.88. Because 207 Pb / 206 The ratio of Pb to the Earth's mass has generally decreased since Earth's formation, so the slope of this inconsistency line should be negative. This TW inconsistency line is consistent with the TW anti-congruence line (given by X=1 / (e...). λ8t -1), Y=(1 / 137.88)×(e λ5t -1) / (e λ8t The intersection of the curves formed by -1) represents the mixed age, which is the age indicated by the inheritance of initial lead and radiogenic lead at that moment. The lower intersection represents the decay age of the radiogenic parent isotope, at which point the proportion of radiogenic lead is the highest.

[0051] In an exemplary embodiment provided in this application, the basic formula and principle of the TW method are as follows: F TERA and GJWASSERBURG pioneered the TW concordance line method for calculating the chronology and common lead values ​​of lunar samples, providing the basic conditions and applicable examples for the application of this method. The TW method can explain the inconsistencies in the initial lead content of different lunar samples. However, when this method was proposed, no quantitative preconditions were given; it was only stated that this method is mainly applicable to qualitative conditions such as isotopic age calculation of samples with high common lead content.

[0052] The core of the TW method is: sample 207 Pb / 206 The Pb ratio is the superposition of initial Pb and radiogenic Pb prior to the age being measured; the initial lead can be determined by the intersection of the nonlinear line and the Y-axis.

[0053] Please see Figure 2 , Figure 2 This is a schematic flowchart illustrating the application of the provided uranium-lead isotope TW dating method in an exemplary embodiment of this application, as shown below. Figure 2As shown, the samples are calcite from the Sanjiang lead-zinc mine and pitchblende from the Guangzitian uranium mine in northern Guangxi. The specific steps for TW dating analysis of the calcite from the Sanjiang lead-zinc mine and the pitchblende from the Guangzitian uranium mine in northern Guangxi are as follows: Step 1: Establish formulas for TW inconsistencies and anticonsistencies in the sample, provide parameters and explain their significance, thereby illustrating the principle and method of TW age calculation. This includes the Earth's formation age, isotopic decay constants, and... 207 Pb / 204 Pb, 206 Pb / 204 Pb, 238 U / 204 The Pb value is referenced from the literature "Xia Yuliang. 2019. Geological Chronology of Uranium Metallogenic in China [M]. Beijing: China Atomic Energy Press, 1-301".

[0054] The corresponding functional module 1 is set up as follows: based on the basic formula of the TW method, it explains the principle and method of age calculation using the TW method.

[0055] Step 2: Based on the initial U-Pb isotopes, calculate the different uranium-lead isotope evolution models for single-stage, two-stage (SK mode), and three-stage evolution. 207 Pb / 206 Pb, 207 Pb / 204 Pb, 206 Pb / 204 Pb, 207 Pb / 206 Pb value (I value). Different evolution models, except for the basic parameters, are derived from "Xia Yuliang. 2019. Geological Chronology of Uranium Metallogenic Geology in China [M]. Beijing: China Atomic Energy Press, 1-301" and "Stacey, JS, Kramers, JD, 1975. Approximation of Terrestrial Lead Isotope Evolution By a Two..." In addition to the values ​​given in the two papers, Stage Model[J]. Earth and Planetary Science Letters, 26(2): 207–221, other parameters are assigned values ​​based on the general parameters derived from the common evolution models of existing U-Pb isotopes.

[0056] Furthermore, the U-Pb three-stage model can be extended to a multi-stage model to calculate the corresponding I value ( 207 Pb / 206 Pb). The final calculation yielded multiple... 207 Pb / 206 The range of lead isotope ratios formed by Pb values ​​(the range of lead isotope ratio values).

[0057] The corresponding functional module 2 is configured to: compare the I value with the example I value to determine whether the TW method is applicable; compare the range of I values ​​calculated by different evolutionary modes with the I value obtained from the example to determine whether the TW age is reliable.

[0058] Step 3: Discuss the reliability of the age mentioned in the previous steps and determine the preconditions for the TW method.

[0059] The corresponding functional module 3 is configured to: determine the reliability of the age based on the I value calculation results, and perform evolution dating of the initial lead based on the TW method to give the geological significance of the sample's age.

[0060] Specifically, a comparison of uranium-lead isotope TW method results for calcite from the Sanjiang lead-zinc mine and pitchblende from the Guangzitian uranium mine in northern Guangxi is shown in the figure below. Figure 3 As shown, for Figure 3 The analysis is as follows: ① Figure 3 (A) is the U-Pb diagram of calcite in the Sanjiang Pb-Zn mine. The TW nonlinear projection points are evenly distributed in the diagram, and I0=0.858, which is consistent with the U-Pb evolution law and the premise of the TW method. It is consistent with the previous test results. This age result is reasonable both mathematically and in terms of isotope theory.

[0061] ② Figure 3 (B) is the U-Pb map of the pitchblende bed of the Guangzitian uranium deposit in Yuechengling, Guibei, Guangxi. The TW inconsistency lines are concentrated in the middle of the distribution and are uneven. The obtained Y-axis intersection point I0=0.22 is meaningless. It does not meet the U-Pb single-to-multi-stage evolution model, nor does it meet the fully radiogenic Pb evolution model. It is unreasonable in both mathematical and isotopic theory. Although the paper gives a consistent weighted average age after ordinary lead correction, the age result has no geological significance due to the unreasonable inconsistency lines.

[0062] ③ Analysis of the Geological Significance of Unreasonable Ages right Figure 3 Reanalysis of the original data in (B) revealed that the I0 value at the intersection of the inconsistency line and the Y-axis exhibits significant radiogenic Pb isotopic characteristics. I0 = 0.22 corresponds to radiogenic Pb at approximately 2980 Ma (μ = 9.26 in the calculation, with the same decay constant as previously stated). This age clearly contradicts the U-Pb evolution characteristics reflected in the pitchblende test data. Therefore, this set of test data likely suggests an open U-Pb isotopic continuum, rendering any U-Pb isotopic dating method inapplicable.

[0063] ④ Conclusion: This application has determined the reliability of TW ages in practical applications, identified the root causes of unreasonable ages, and, after reanalysis of the data, demonstrated the potential geological significance of isotopic ages. The method described in this application can serve as an effective method for determining the reliability of TW isotopic ages, and the applicable criteria for this method are given.

[0064] In summary, the uranium-lead isotope TW dating method of this application is based on single-stage, multi-stage, and Stacy-Kramers (SK) models of U-Pb isotopes. The values ​​of the intersection points of the inconsistencies with the Y-axis are derived by referring to the TW method inconsistency formula. 207 Pb / 206 The formula for calculating U-Pb isotopes (Pb)0 is used, and initial conditions and parameters for U-Pb isotopes are set to calculate the evolution of the Earth from its formation to the present. 207 Pb / 206 Pb value, establishing a set of intersection points of inconstituent lines and the Y-axis based on the TW method. 207 Pb / 206 The Pb isotope ratio range limits the technical method system that preconditions for its application. Therefore, this application calculates the I value using a multi-stage model based on the U-Pb isotope principle. 207 Pb / 206 The TW inconsistency line (Pb) limits the range of values ​​for the Y-axis intersection point. The results are simple, clear, and reliable, making it one of the effective conditions for defining TW dating. Furthermore, this application addresses the issue of U-Pb isotope closure, applicable to TW age calculations of multi-stage U-Pb evolution systems in Earth samples, and also suitable for determining the applicability of TW age calculations using whole-rock, single-mineral TIMS, and micro-area in-situ U-Pb isotope testing data.

[0065] Please see Figure 4 , Figure 4 An exemplary embodiment of this application illustrates a uranium-lead isotope TW dating system, such as... Figure 4 As shown, this application provides a uranium-lead isotope TW dating system 400, comprising: The acquisition module 401 is used to acquire the initial U-Pb isotope values ​​of the sample; The multi-stage geological evolution module 402 is used to perform multi-stage geological evolution based on the initial U-Pb isotope values, determine the lead isotope ratio range of the sample, and the lead isotope ratio range characterizes the range of values ​​of the intersection point of the TW inconsistency line and the TW anticonsistency line of the sample. The TW dating module 403 is used to perform TW dating on samples based on the lead isotope ratio range to obtain the sample's age data.

[0066] The uranium-lead isotope TW dating system 400 provided in this application, through a multi-stage geological evolution module 402, performs multi-stage geological evolution based on the initial U-Pb isotope values ​​of the sample to determine the range of lead isotope ratios of the sample. This range characterizes the range of values ​​at the intersection of the TW inconsistency line and the anti-TW concordance line of the sample. The TW dating module 403, based on the lead isotope ratio range, limits the applicable conditions for TW dating of the sample, thereby constraining the age results and obtaining a reliable age. Thus, by accurately calculating the multi-stage evolution of the uranium-lead isotopes of the sample and then performing TW dating based on the evolution results, the uranium-lead isotope dating of the sample can be geologically significant, thereby improving the reliability of sample dating. Optionally, the multi-stage geological evolution module 402 is specifically used for: Based on the initial U-Pb isotope values, a single-stage geological evolution was performed to obtain the single-stage lead isotope ratio of the sample. Two-stage geological evolution was performed based on the initial U-Pb isotope values ​​to obtain the two-stage lead isotope ratios of the sample. Based on the initial U-Pb isotope values, a three-stage geological evolution was performed to obtain the three-stage lead isotope ratios of the sample. Based on single-stage, two-stage, and three-stage lead isotope ratios, a range of lead isotope ratios for the sample is formed.

[0067] Optionally, the sample is a lead isotope standard of the Earth; The multi-stage geological evolution module 402 is specifically used to execute the evolution formula corresponding to the single-stage lead isotope ratio as follows: I1=( 207 Pb / 204 Pb)1 / ( 206 Pb / 204 Pb)1 ( 206 Pb / 204 Pb)1= 206 Pb / 204 Pb0+ 238 U / 204 Pb(e λ8t0 -1) ( 207 Pb / 204 Pb)1= 207 Pb / 204 Pb0+ 238 U / 204 Pb×137.88 (e λ8t0 -1) Wherein, I1 represents the single-stage lead isotope ratio. 238 U / 204Pb is the initial U-Pb isotopic value. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, where t0 is the formation age of the Earth.

[0068] Optionally, the sample is a lead isotope standard of the Earth; Multi-stage geological evolution module 402 is specifically used to execute the evolution formula corresponding to the two-stage lead isotope ratios: I2 = ( 207 Pb / 206 Pb) SK =( 207 Pb / 204 Pb)2 / ( 206 Pb / 204 Pb)2 ( 206 Pb / 204 Pb)2= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 -1) ( 207 Pb / 204 Pb)2= 207 Pb / 204 Pb0+ 238 U / ( 204 Pb×137.88)0×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 -1) Wherein, I2 represents the two-stage lead isotope ratio in the SK mode. 238 U / 204 Pb is the initial U-Pb isotopic value. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, t1 is the crust-mantle differentiation age of the Earth, ( 238 U / 204Pb)1 is the value that evolved from the crust-mantle differentiation at 3.7 Ga to the present. 238 U / ( 204 Pb × 137.88)0 represents the Earth's evolution from its formation to the present day. 235 U / 204 Pb value, λ5 is 235 The decay constant of U, 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 Pb value.

[0069] Optionally, the sample is a lead isotope standard of the Earth; The multi-stage geological evolution module 402 is specifically used to execute the evolution formula corresponding to the three-stage lead isotope ratios: I3 = ( 207 Pb / 204 Pb)3 / ( 206 Pb / 204 Pb)3 ( 206 Pb / 204 Pb)3= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 - e λ8t2 ) +( 238 U / 204 Pb)2×(e λ8t2 -1) ( 207 Pb / 204 Pb)3= 207 Pb / 204 Pb0+ 235 U / 204 Pb×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 - e λ5t2 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t2 -1) Wherein, I3 represents the three-stage lead isotope ratio. 238 U / 204 Pb and235 U / 204 All Pb values ​​are initial U-Pb isotopic values. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, t1 is the crust-mantle differentiation age of the Earth, ( 238 U / 204 Pb)1 is the value of crust-mantle differentiation and evolution from 3.7 Ga to the present, and t2 is the geological formation time of the sample. 238 U / 204 Pb)2 represents the value of the geological body formed and evolved to the present day, and λ5 represents... 235 The decay constant of U, 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 The Pb value is equal to ( 235 U / 204 Pb)1.

[0070] Optionally, the TW dating module 403 is specifically used for: Using the lead isotope ratio range as a precondition for the TW method, the initial lead that matches the lead isotope ratio range is matched from the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The TW method was used to date the samples based on the initial lead content using different evolution systems of uranium-lead isotopes, thus obtaining the sample age data.

[0071] Optionally, in the uranium-lead isotope TW dating system 400, a TW discrepancy line for the sample is provided, the basic formula of which is: I= 207 Pb / 206 Pb= 238 U / 206 U×(e) λ5t -1) / 137.88+I0 Where I is 207 Pb / 206 The test value of Pb, (e λ5t -1) / 137.88 is the slope, λ5 is 235 The decay constant of U, t is the geological formation time of the sample, and I0 is the initial lead isotope ratio. The sample also has a TW anti-uniformity line, which is formed by X=1 / (e λ8t -1), Y=(1 / 137.88)×(e λ5t-1) / (e λ8t -1) forms the curve.

[0072] It should be noted that the uranium-lead isotope TW dating system and the uranium-lead isotope TW dating method provided in the above embodiments belong to the same concept. The specific operation methods of each module and unit have been described in detail in the method embodiments and will not be repeated here. In practical applications, the uranium-lead isotope TW dating system provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above. This is not a limitation here.

[0073] A computing device according to an embodiment of this application includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, it implements some or all of the steps of the above-described uranium-lead isotope TW dating method.

[0074] The computing device can be a computer, and the corresponding program is computer software. The parameters and steps in the computing device described above can be referred to the parameters and steps in the embodiment of the uranium-lead isotope TW dating method mentioned above, and will not be repeated here.

[0075] This application embodiment discloses a computer-readable storage medium storing instructions that, when executed, perform the steps of the aforementioned uranium-lead isotope TW dating method. The computer-readable storage medium can be a non-transitory computer-readable storage medium, including various media capable of storing program code such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks; it can also be a transient computer-readable storage medium.

[0076] One embodiment of this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the aforementioned uranium-lead isotope TW dating method. The technical solution of this disclosure embodiment can be embodied in the form of a software product stored in a storage medium, including one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method of this disclosure embodiment.

[0077] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, devices, media, and products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0078] Those skilled in the art will recognize that this application can be implemented as a system, method, or computer program product. Therefore, this disclosure can be implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "module" or "system." Furthermore, in some embodiments, this application can also be implemented as a computer program product contained in one or more computer-readable media, which contains computer-readable program code. Computer-readable storage media can be, for example, but not limited to—electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0080] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for TW dating of uranium-lead isotopes, characterized in that, include: Obtain the initial U-Pb isotope values ​​of the sample; Based on the initial U-Pb isotope values, a multi-stage geological evolution was performed to determine the lead isotope ratio range of the sample. The lead isotope ratio range characterizes the range of values ​​at the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. Based on the lead isotope ratio range, the applicable conditions for TW dating of the sample are defined, and the age data of the sample is obtained.

2. The method according to claim 1, characterized in that, The process of determining the lead isotope ratio range of the sample by performing multi-stage geological evolution based on the initial U-Pb isotope values ​​includes: Based on the initial U-Pb isotope values, a single-stage geological evolution was performed to obtain the single-stage lead isotope ratio of the sample. Based on the initial U-Pb isotope values, a two-stage geological evolution was performed to obtain the two-stage lead isotope ratio values ​​of the sample. Based on the initial U-Pb isotope values, a three-stage geological evolution was performed to obtain the three-stage lead isotope ratios of the sample. Based on the single-stage lead isotope ratio, the two-stage lead isotope ratio, and the three-stage lead isotope ratio, the lead isotope ratio range of the sample is formed.

3. The method according to claim 2, characterized in that, The sample is a lead isotope standard for Earth; The single-stage geological evolution based on the initial U-Pb isotope values ​​yields the single-stage lead isotope ratio of the sample, and the corresponding evolution formula is as follows: I1=( 207 Pb / 204 Pb)1 / ( 206 Pb / 204 Pb)1 ( 206 Pb / 204 Pb)1= 206 Pb / 204 Pb0+ 238 U / 204 Pb(e λ8t0 -1) ( 207 Pb / 204 Pb)1= 207 Pb / 204 Pb0+ 238 U / 204 Pb×137.88 (e λ8t0 -1) Wherein, I1 is the single-stage lead isotope ratio. 238 U / 204 Pb is the initial U-Pb isotope value. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, where t0 is the formation age of the Earth.

4. The method according to claim 2, characterized in that, The sample is a lead isotope standard for Earth; Based on the initial U-Pb isotope values, a two-stage geological evolution was performed to obtain the two-stage lead isotope ratios of the sample. The corresponding evolution formula is as follows: I2=( 207 Pb / 206 Pb) SK =( 207 Pb / 204 Pb)2 / ( 206 Pb / 204 Pb)2 ( 206 Pb / 204 Pb)2= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 -1) ( 207 Pb / 204 Pb)2= 207 Pb / 204 Pb0+ 238 U / ( 204 Pb×137.88)0×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 -1) Wherein, I2 represents the two-stage lead isotope ratio in the SK mode. 238 U / 204 Pb is the initial U-Pb isotope value. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, t1 is the crust-mantle differentiation age of the Earth, ( 238 U / 204 Pb)1 is the value that evolved from the crust-mantle differentiation at 3.7 Ga to the present. 238 U / ( 204 Pb × 137.88)0 represents the Earth's evolution from its formation to the present day. 235 U / 204 Pb value, λ5 is 235 The decay constant of U, 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 Pb value.

5. The method according to claim 2, characterized in that, The sample is a lead isotope standard for Earth; The three-stage geological evolution based on the initial U-Pb isotope values ​​yields the three-stage lead isotope ratios of the sample, and the corresponding evolution formula is as follows: I3=( 207 Pb / 204 Pb)3 / ( 206 Pb / 204 Pb)3 ( 206 Pb / 204 Pb)3= 206 Pb / 204 Pb0+ 238 U / 204 Pb×(e λ8t0 - e λ8t1 )+( 238 U / 204 Pb)1×(e λ8t1 - e λ8t2 ) +( 238 U / 204 Pb)2×(e λ8t2 -1) ( 207 Pb / 204 Pb)3= 207 Pb / 204 Pb0+ 235 U / 204 Pb×(e λ5t0 - e λ5t1 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t1 -e λ5t2 )+ 238 U / ( 204 Pb×137.88)1×(e λ5t2 -1) Wherein, I3 represents the lead isotope ratio of the three stages. 238 U / 204 Pb and 235 U / 204 All Pb values ​​are the initial U-Pb isotope values. 206 Pb / 204 Pb0 and 207 Pb / 204 Pb0 represents the Pb isotope values ​​from the Earth's formation to the present day, and λ8 represents... 238 The decay constant of U, t0 is the formation age of the Earth, t1 is the crust-mantle differentiation age of the Earth, ( 238 U / 204 Pb)1 is the value of crust-mantle differentiation and evolution from 3.7 Ga to the present, and t2 is the geological formation time of the sample. 238 U / 204 Pb)2 represents the value of the geological body formed and evolved to the present day, and λ5 represents... 235 The decay constant of U, 238 U / ( 204 Pb×137.88)1 represents the 3.7 Ga crust-mantle differentiation to date. 235 U / 204 The Pb value is equal to ( 235 U / 204 Pb)1.

6. The method according to any one of claims 1 to 5, characterized in that, The method of determining the applicable conditions for TW dating of the sample based on the lead isotope ratio range to obtain the age data of the sample includes: Using the lead isotope ratio range as a prerequisite for the TW method, the initial lead that matches the lead isotope ratio range is matched from the intersection of the TW inconsistency line and the TW anticonsistency line of the sample. The TW method was used to date the sample using different evolution systems of uranium-lead isotopes based on the initial lead, thus obtaining the sample's age data.

7. The method according to any one of claims 1 to 5, characterized in that, The basic formula for the TW inconsistency line is: I= 207 Pb / 206 Pb= 238 U / 206 U×(e λ5t -1) / 137.88+I0 Where I is 207 Pb / 206 The test value of Pb, (e λ5t -1) / 137.88 is the slope, λ5 is 235 The decay constant of U, t is the geological formation time of the sample, and I0 is the initial lead isotope ratio. The TW anti-consistency line is derived from X=1 / (e λ8t -1), Y=(1 / 137.88)×(e λ5t -1) / (e λ8t -1) forms the curve.

8. A uranium-lead isotope TW dating system, characterized in that, include: The acquisition module is used to acquire the initial U-Pb isotope values ​​of the sample; A multi-stage geological evolution module is used to perform multi-stage geological evolution based on the initial U-Pb isotope value, and to determine the lead isotope ratio range of the sample. The lead isotope ratio range characterizes the range of values ​​of the intersection point of the TW inconsistency line and the TW anticonsistency line of the sample. The TW dating module is used to limit the applicable conditions for TW dating of the sample based on the lead isotope ratio range, and to obtain the age data of the sample.

9. A computing device comprising a memory, a processor, and a program stored in the memory and running on the processor, characterized in that, When the processor executes the program, it implements the steps of the uranium-lead isotope TW dating method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a terminal device, cause the terminal device to perform the steps of the uranium-lead isotope TW dating method as described in any one of claims 1 to 7.

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