Paleo-water depth and hydrodynamic force condition quantitative reconstruction method based on marginal and microscopic structures of Shiwuyi laminated stone

Abstract

The invention relates to the technical field of geological analysis, in particular to a paleo-water depth and hydrodynamic condition quantitative reconstruction method based on a marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure of marginal and microstructure. The system extracts structural parameters such as the thickness of the lamina, the shape fluctuation degree, the lateral extension continuity and the related microstructures of the microbial mat. And by inputting actual laminated stone structure parameters into the model, synchronous calculation and output of paleo-water depth values and hydrodynamic condition grades are realized. According to the method, a traditional paleo-water depth recovery method depending on a single substitute index is broken through, high-precision, repeatable and comparable quantitative reconstruction of the water depth and hydrodynamic conditions of the shallow sea sedimentary environment in the Shiwujian is achieved, and a reliable technical means is provided for research on early life activity environments and sedimentary dynamics.

Description

Technical Field

[0001] This invention relates to the field of geological analysis technology, specifically to a method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structures of Cambrian stromatolites. Background Technology

[0002] This invention relates to the fields of sedimentary geology, paleoenvironmental reconstruction, and digital geological analysis. Specifically, it pertains to a method for quantitatively reconstructing paleowater depth and hydrodynamic conditions in early marine sedimentary environments based on the macro- and micro-structural characteristics of Cambrian stromatolites. This technique comprehensively utilizes high-resolution 3D imaging, digital petrology, structural parameter extraction, and mathematical modeling to achieve quantitative inversion of the physical conditions of early marine environments starting from the sedimentary structures themselves. It is suitable for detailed environmental analysis of carbonate sedimentary systems in the pre-biological disturbance period.

[0003] A search revealed that patent application number CN201410101705.2 provides a method for quantitatively calculating paleowater depth in lacustrine sediments. This method establishes an empirical relationship between the total organic carbon content of lakebed sediments and water depth by screening modern analogous lakes. It then combines the total organic carbon test results of mudstone in the study area with stratigraphic thickness parameters to achieve quantitative calculation and planar distribution representation of paleowater depth. This technology relies on modern lake analogies and a single geochemical indicator, and has certain applicability in lacustrine sedimentary environments. However, its calculation process is mainly based on statistical correlations and lacks direct constraints on the formation mechanism of sedimentary structures.

[0004] However, the aforementioned traditional techniques have significant limitations. First, the research objects are limited to lacustrine fine-grained sedimentary systems, making them unsuitable for Cambrian marine carbonate backgrounds. Second, they use chemical indicators such as total organic carbon as the main control variables, failing to incorporate direct physical response information of sedimentary structures formed under hydrodynamic conditions. Third, the computational models heavily rely on modern environmental analogies, making it difficult to reflect the unique marine chemical conditions and biodeposition mechanisms of the Cambrian. This invention, through quantitative analysis of the macro- and micro-structures of stromatolites, combined with independently constrained paleo-seawater chemical and paleo-geographical parameters, establishes a specific mathematical model relating structural parameters to paleo-water depth and hydrodynamic energy levels. This fundamentally overcomes the shortcomings of traditional methods, such as insufficient environmental applicability, weak expression of physical mechanisms, and limited model generalization ability.

[0005] Therefore, we propose a quantitative reconstruction method for paleowater depth and hydrodynamic conditions based on the macro- and micro-structures of Cambrian stromatolites. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] The purpose of this invention is to provide a method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structures of Cambrian stromatolites, so as to solve the problems mentioned in the background art.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A quantitative reconstruction method for paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites includes the following steps:

[0011] Step 1: Collect stromatolite specimens from Cambrian strata and prepare continuous profile samples;

[0012] Step 2: Use high-resolution 3D imaging technology to scan the sample and obtain its complete macro- and micro-structural digital model;

[0013] Step 3: Extract the thickness, morphological undulation, lateral extension continuity, and microstructural parameters related to the microbial mat from the digital model;

[0014] Step 4: Based on geochemical principles and stratigraphic evidence, independently calculate the basic chemical parameters of paleoseawater and regional paleogeographic background parameters during the Cambrian period.

[0015] Step 5: Based on the exclusive ancient parameters obtained in Step 4, establish a mathematical model for the quantitative relationship between the Cambrian lamellar structure parameters and the ancient water depth and hydrodynamic energy level.

[0016] Step six: Input the actual structural parameters obtained in step three into the ancient quantitative model established in step five to calculate and output the ancient water depth value and hydrodynamic condition level.

[0017] As a preferred technical solution, the process of collecting stromatolite specimens from Cambrian strata and preparing continuous profile samples in step one is further defined as follows: directional sampling is carried out along the vertical growth direction of the same sedimentary sequence; profile samples with constant thickness and undamaged bedding are obtained by continuous cutting according to the macroscopic growth axis of the stromatolite; and the sampling effectiveness is constrained by a quantitative criterion for sample continuity, with its continuity index... Calculate according to the following formula:

[0018]

[0019] in, Indicates the first The vertical length of a continuous lamellar segment. Indicates the number of striation segments. This represents the total height of a single profile sample. The standard deviation of the lamellar thickness within the profile is represented by this continuity index, which comprehensively characterizes the growth integrity and bedding stability of stromatolites at the sampling scale. This is achieved by controlling... Within the preset threshold range, the prepared continuous profile samples are ensured to maintain the true in-situ growth characteristics in both macroscopic morphology and microscopic laminar structure, thus providing a basic sample with statistical consistency and physical interpretability for subsequent three-dimensional imaging and structural parameter extraction.

[0020] As a preferred technical solution, step two employs multi-scale high-resolution three-dimensional imaging technology to perform layer-by-layer voxel scanning of continuous cross-sectional samples. By simultaneously acquiring macroscopic layering undulation morphology and microscopic internal structure information of the laminae, a three-dimensional structural digital model under a unified coordinate system is constructed. Furthermore, a resolution adaptive fusion algorithm is introduced during model reconstruction to eliminate geometric distortion caused by imaging at different scales. Specifically, this is constrained by the following structural consistency function:

[0021]

[0022] in, Indicates the first Height field of macroscopic laminar interface This represents the local height field of the corresponding micro-layered unit. Represents the spatial gradient operator. The effective number of lamellar layers is used to quantify the consistency between macroscopic fluctuations and microscopic structures in spatial variation trends, and serves as an optimization target in the 3D reconstruction process. This ensures that the obtained digital model maintains the continuity of macroscopic morphology and the authenticity of microscopic structure simultaneously, providing a stable and unified structural basis for the subsequent quantitative extraction of lamellar parameters.

[0023] As a preferred technical solution, step three specifically includes constructing a multi-scale structural analysis process based on the three-dimensional macro-micro structural digital model obtained in step two. This involves reconstructing the three-dimensional curved surface of the stromatolite layer interface and tracing it layer by layer to obtain the normal distance between adjacent layers and form a layer thickness sequence. Simultaneously, spatial gradient calculations are performed on the surface of each layer to quantify its morphological undulation characteristics, and continuous tracing is performed along the main growth direction to characterize lateral extension stability. Furthermore, microstructural parameters are extracted by combining the spatial distribution characteristics of micropores, microfolds, and directional fiber structures within the microbial mat, including the comprehensive structural index of the layers. Calculate as follows:

[0024]

[0025] In the formula Indicates the first Layer thickness at each sampling location This indicates the average thickness of the same texture layer. This represents the normalized undulation gradient of the surface of the laminar layer at the corresponding location. This represents the continuity coefficient along the lateral extension direction at that location. The number of sampling points is indicated, and the above structural indices are used to quantify the uniformity of lamellar thickness, the intensity of morphological undulations, and the degree of lateral continuity; at the same time, a parameter for the orderedness of the microbial mat structure is defined. This is used to characterize the response of microstructures to environmental stability, and its calculation method is as follows:

[0026]

[0027] in, Indicates the first Characteristic scale of micro-structural units This indicates the angle between its principal orientation and the overall growth normal. The number of microstructure types is indicated by... This method quantitatively reflects the growth directionality of microbial mats and the degree of hydrodynamic disturbance, providing high-resolution structural input parameters for subsequent quantitative inversion of paleowater depth and hydrodynamic conditions.

[0028] As a preferred technical solution, the calculation of the basic chemical parameters of the Cambrian paleoseawater in step four is achieved by jointly inverting the stable isotopic composition and trace element distribution characteristics of syngenetic carbonates in stromatolites, specifically constructing the paleoseawater chemical constraint index. Its expression is:

[0029]

[0030] in, and The carbon and oxygen isotope values ​​after correction for diagenetic influences were characterized. Characterizing the ionic composition of seawater during precipitation, this index is used to quantify the saturation state and alkalinity level of the Cambrian seawater carbonate system. The results serve as the chemical boundary condition input for subsequent quantitative models of lamellar structure parameters, thereby avoiding interference from modern seawater parameters in paleoenvironment inversion.

[0031] As a preferred technical solution, in step four, the regional paleogeographic background parameters are quantitatively coupled with stratigraphic evidence and sedimentary rate inversion results to construct paleogeographic constraint factors. Its expression is:

[0032]

[0033] in, and These represent the maximum and minimum burial depths within the same stromatolite sequence. To correspond to the deposition timeframe, The cumulative value of the compaction deformation is used to quantitatively characterize the tectonic stability and relative subsidence rate of the Cambrian basin, and provides an independent paleogeographic scale constraint for establishing the mathematical mapping relationship between the lamellar structure parameters and the paleowater depth and hydrodynamic energy level.

[0034] As a preferred technical solution, the quantitative relationship mathematical model established in step five uses the laminar thickness parameters extracted in step three. morphological undulation parameters Lateral extension continuity parameters The paleosea basic chemical parameters obtained in step four After unifying the dimensions, a quantitative response function for paleowater depth is constructed. Its expression is:

[0035]

[0036] in, The scale factor is determined based on the paleogeographic background parameters of the Cambrian region. To reflect the moderating index of the influence of paleosea chemical environment on the vertical growth rate of lamellarity, this function couples lamellar geometric features with paleosea chemical conditions to achieve quantitative inversion of the effective water depth when stromatolites are formed. This makes the water depth results directly controlled by observable structural parameters and independently calculated paleoenvironmental parameters, thereby avoiding systematic bias caused by a single morphological index.

[0037] As a preferred technical solution, the quantitative model of hydrodynamic energy level in step five is based on the stability of the lamellar structure and the preservation characteristics of the microbial mat, establishing a hydrodynamic index. Its expression is;

[0038]

[0039] in, The regional depositional energy correction factor is determined in step four. The integrity index of the mat body is calculated from the microstructure parameters related to the micro-mat. This model quantitatively characterizes the hydrodynamic intensity gradation in the Cambrian sedimentary environment by the response relationship of laminar undulation to shear disturbance and the characterization of continuity to lateral hydrodynamic stability. This ensures that the output hydrodynamic energy level corresponds one-to-one with the actual stress environment during the growth of stromatolites, thereby improving the physical consistency and comparability of the paleohydrodynamic reconstruction results.

[0040] As a preferred technical solution, the process of inputting the actual structural parameters obtained in step three into the ancient quantitative model established in step five, and using a unified normalization mapping and coupled solution algorithm to process the laminar thickness parameters... morphological undulation parameters Lateral extension continuity parameters and microbial mat microstructure index Simultaneous solution is performed to generate continuous output values ​​of paleowater depth. The calculation relationship is as follows:

[0041]

[0042] in, , , , The Cambrian-specific weighting coefficients determined in step five. The basic chemical and paleogeographic integrated environmental parameters obtained in step four are... This is an environmental modulation factor used to suppress the amplification effect of non-depth-controlling factors. This formula achieves a stable mapping of macro- and micro-structural information to a single paleodepth physical quantity, ensuring that the output results have geological comparability and regional consistency.

[0043] As a preferred technical solution, the output of the hydrodynamic condition level is based on the paleowater depth value. Composite index of structural disturbance The joint judgment, in which The hydrodynamic energy level is obtained by calculating the spatiotemporal fluctuation amplitude of the structural parameters in step three, and determined by the following discriminant function. :

[0044]

[0045] in, and The scale coefficients are calibrated by the Cambrian quantitative model in step five, with the following symbol: This indicates a floor operation, used to convert continuous calculation results into discrete hydrodynamic levels. This discrimination method enables synchronous constraints between paleodepth control terms and structural disturbance response terms, thereby outputting hydrodynamic condition level results with hierarchical stability.

[0046] (III) Beneficial Effects

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] 1. This scheme combines the acquisition of macroscopic continuous profiles of Cambrian stromatolites with quantitative characterization of their microstructure, constructing a complete technical chain from physical geological carriers to a digital parameter system. This significantly improves the completeness and structural continuity of stromatolite information acquisition and avoids the problem of missing environmental information caused by traditional single-point sampling.

[0049] 2. By acquiring a macro-micro integrated digital model through high-resolution three-dimensional imaging, the geometric morphology, spatial undulations, and microstructural features of the stromatolite layers can be accurately expressed under a unified coordinate system, effectively overcoming the technical limitations of two-dimensional thin-section analysis in reflecting the real spatial structure.

[0050] 3. This scheme is the first to synergistically quantify and extract parameters such as lamellar thickness, morphological undulation, lateral extension continuity, and microstructural parameters of microbial mats, thereby achieving a multi-dimensional characterization of the growth dynamics of stromatolites and providing a stable and repeatable structural index system for the identification of paleohydrodynamic conditions.

[0051] 4. By introducing geochemical and stratigraphic evidence to independently invert the basic chemical parameters of Cambrian paleoseawater and regional paleogeographic background parameters, we can avoid the systematic bias caused by directly applying modern oceanographic parameters and significantly improve the temporal adaptability and geological rationality of paleoenvironment reconstruction.

[0052] 5. A quantitative relationship model between lamellar structure parameters and paleowater depth and hydrodynamic energy level was established based on specific ancient parameters, which transformed the paleoenvironmental interpretation that originally relied on empirical judgment into a calculable and comparable mathematical expression, thereby enhancing the objectivity and verifiability of the results.

[0053] 6. By directly inputting measured structural parameters into the ancient quantitative model and outputting continuous paleowater depth values ​​and discretized hydrodynamic levels, the quantitative reconstruction and standardized expression of Cambrian paleowater depth and hydrodynamic conditions were realized, providing a unified technical basis for comparative studies of stromatolite records in different regions and time periods. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the overall method of the present invention;

[0056] Figure 2 This is a schematic diagram of sample preparation according to the present invention;

[0057] Figure 3 This is a schematic diagram of the three-dimensional imaging of the present invention;

[0058] Figure 4 This is a schematic diagram of parameter extraction according to the present invention;

[0059] Figure 5 This is a schematic diagram of the quantitative model of the present invention. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Example 1:

[0062] According to the appendix Figure 1-5 As shown, this embodiment of the invention provides a method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structures of Cambrian stromatolites, including the following steps:

[0063] Step 1: Collect stromatolite specimens from Cambrian strata and prepare continuous profile samples;

[0064] Step 2: Use high-resolution 3D imaging technology to scan the sample and obtain its complete macro- and micro-structural digital model;

[0065] Step 3: Extract the thickness, morphological undulation, lateral extension continuity, and microstructural parameters related to the microbial mat from the digital model;

[0066] Step 4: Based on geochemical principles and stratigraphic evidence, independently calculate the basic chemical parameters of paleoseawater and regional paleogeographic background parameters during the Cambrian period.

[0067] Step 5: Based on the exclusive ancient parameters obtained in Step 4, establish a mathematical model for the quantitative relationship between the Cambrian lamellar structure parameters and the ancient water depth and hydrodynamic energy level.

[0068] Step six: Input the actual structural parameters obtained in step three into the ancient quantitative model established in step five to calculate and output the ancient water depth value and hydrodynamic condition level.

[0069] Example 2:

[0070] Based on the above embodiments, the process of collecting stromatolite specimens from Cambrian strata and preparing continuous profile samples in step one is further defined as follows: directional sampling is carried out along the vertical growth direction of the same sedimentary sequence; profile samples with constant thickness and undamaged bedding are obtained by continuous cutting according to the macroscopic growth axis of the stromatolite; and the sampling effectiveness is constrained by a quantitative criterion for sample continuity, the continuity index of which is... Calculate according to the following formula:

[0071]

[0072] in, Indicates the first The vertical length of a continuous lamellar segment. Indicates the number of striation segments. This represents the total height of a single profile sample. The standard deviation of the lamellar thickness within the cross-section is represented by this continuity index, which comprehensively characterizes the growth integrity and bedding stability of stromatolites at the sampling scale. This is achieved by controlling... Within the preset threshold range, the prepared continuous profile samples are ensured to maintain the true in-situ growth characteristics in both macroscopic morphology and microscopic laminar structure, thus providing a basic sample with statistical consistency and physical interpretability for subsequent three-dimensional imaging and structural parameter extraction.

[0073] In practical applications, the continuity index The threshold is usually set to For example, calculations of continuous stromatolite profile samples from the Zhangxia Formation of the Cambrian System in North China show that... The value is $0.89, corresponding to , , This indicates that the sample has good stratification continuity and statistical representativeness.

[0074] Example 3:

[0075] Based on the above embodiments, step two employs multi-scale high-resolution three-dimensional imaging technology to perform layer-by-layer voxel scanning of continuous cross-sectional samples. By simultaneously acquiring macroscopic layering undulation morphology and microscopic internal structure information of the laminae, a three-dimensional structural digital model under a unified coordinate system is constructed. During the model reconstruction process, a resolution adaptive fusion algorithm is introduced to eliminate geometric distortions caused by imaging at different scales. Specifically, this is constrained by the following structural consistency function:

[0076]

[0077] in, Indicates the first Height field of macroscopic laminar interface This represents the local height field of the corresponding micro-layered unit. Represents the spatial gradient operator. The effective number of lamellar layers is used to quantify the consistency between macroscopic fluctuations and microscopic structures in spatial variation trends, and serves as an optimization target in the 3D reconstruction process. This ensures that the obtained digital model maintains the continuity of macroscopic morphology and the authenticity of microscopic structure simultaneously, providing a stable and unified structural basis for the subsequent quantitative extraction of lamellar parameters.

[0078] In actual imaging, the resolution of the macroscopic layer is set to... Microscopic texture resolution reaches Through structural consistency function After optimization, its value is usually greater than $0.92$, indicating that the macroscopic and microscopic structures are highly consistent in terms of gradient changes, effectively eliminating geometric distortion in multi-scale imaging.

[0079] Example 4:

[0080] Based on the above embodiments, step three specifically includes constructing a multi-scale structural analysis process based on the three-dimensional macro-micro structural digital model obtained in step two. This involves reconstructing the three-dimensional curved surface of the stromatolite layer interface and tracing it layer by layer to obtain the normal distance between adjacent layers and form a layer thickness sequence. Simultaneously, spatial gradient calculations are performed on the surface of each layer to quantify its morphological undulation characteristics, and continuous tracing is performed along the main growth direction to characterize lateral extension stability. Furthermore, microstructural parameters are extracted by combining the spatial distribution characteristics of micropores, microfolds, and directional fiber structures within the microbial mat, including the comprehensive structural index of the layers. Calculate as follows:

[0081]

[0082] In the formula Indicates the first Layer thickness at each sampling location This indicates the average thickness of the same texture layer. This represents the normalized undulation gradient of the surface of the laminar layer at the corresponding location. This represents the continuity coefficient along the lateral extension direction at that location. The number of sampling points is indicated, and the above structural indices are used to quantify the uniformity of lamellar thickness, the intensity of morphological undulations, and the degree of lateral continuity; at the same time, a parameter for the orderedness of the microbial mat structure is defined. This is used to characterize the response of microstructures to environmental stability, and its calculation method is as follows:

[0083]

[0084] in, Indicates the first Characteristic scale of micro-structural units This indicates the angle between its principal orientation and the overall growth normal. The number of microstructure types is indicated by... This method quantitatively reflects the growth directionality of microbial mats and the degree of hydrodynamic disturbance, providing high-resolution structural input parameters for subsequent quantitative inversion of paleowater depth and hydrodynamic conditions.

[0085] Table 1 Typical values ​​of stratigraphic parameters (taking Zhangxia Formation as an example)

[0086] Parameter symbol Parameter name Range of values unit Texture thickness 0.1–2.5 mm Laminar composite structure index 0.3–1.8 Dimensionless Microbial mat structural order 0.15–0.75 Dimensionless Surface undulation gradient 0.02–0.35 mm / mm

[0087] Example 5:

[0088] Based on the above embodiments, the calculation of the basic chemical parameters of Cambrian paleoseawater in step four is achieved by jointly inverting the stable isotopic composition and trace element distribution characteristics of syngenetic carbonates in stromatolites, specifically constructing the paleoseawater chemical constraint index. Its expression is:

[0089]

[0090] in, and The carbon and oxygen isotope values ​​after correction for diagenetic influences were characterized. Characterizing the ionic composition of seawater during precipitation, this index is used to quantify the saturation state and alkalinity level of the Cambrian seawater carbonate system. The results serve as the chemical boundary condition input for subsequent quantitative models of lamellar structure parameters, thereby avoiding interference from modern seawater parameters in paleoenvironment inversion.

[0091] In step four, the regional paleogeographic background parameters are quantitatively coupled with stratigraphic evidence and sedimentary rate inversion results to construct paleogeographic constraint factors. Its expression is:

[0092]

[0093] in, and These represent the maximum and minimum burial depths within the same stromatolite sequence. To correspond to the deposition timeframe, The cumulative value of the compaction deformation is used to quantitatively characterize the tectonic stability and relative subsidence rate of the Cambrian basin, and provides an independent paleogeographic scale constraint for establishing the mathematical mapping relationship between the lamellar structure parameters and the paleowater depth and hydrodynamic energy level.

[0094] Geochemical analysis of Cambrian samples from North China yielded paleosea chemical constraint indices. Typical value Paleogeographic constraint factors The value ranged from $0.6 to $1.4, indicating that the seawater was carbonate-saturated and the tectonic environment was relatively stable at that time.

[0095] Example 6:

[0096] Based on the above embodiments, the quantitative relationship mathematical model established in step five uses the laminar thickness parameters extracted in step three. morphological undulation parameters Lateral extension continuity parameters The paleosea basic chemical parameters obtained in step four After unifying the dimensions, a quantitative response function for paleowater depth is constructed. Its expression is:

[0097]

[0098] in, The scale factor is determined based on the paleogeographic background parameters of the Cambrian region. To reflect the moderating index of the influence of paleosea chemical environment on the vertical growth rate of lamellarity, this function couples lamellar geometric features with paleosea chemical conditions to achieve quantitative inversion of the effective water depth when stromatolites are formed. This makes the water depth results directly controlled by observable structural parameters and independently calculated paleoenvironmental parameters, thereby avoiding systematic bias caused by a single morphological index.

[0099] The quantitative model of hydrodynamic energy levels in step five is based on the stability of the lamellar structure and the preservation characteristics of the microbial mat, establishing a hydrodynamic index. Its expression is;

[0100]

[0101] in, The regional depositional energy correction factor is determined in step four. The integrity index of the mat body is calculated from the microstructure parameters related to the micro-mat. This model quantitatively characterizes the hydrodynamic intensity gradation in the Cambrian sedimentary environment by the response relationship of laminar undulation to shear disturbance and the characterization of continuity to lateral hydrodynamic stability. This ensures that the output hydrodynamic energy level corresponds one-to-one with the actual stress environment during the growth of stromatolites, thereby improving the physical consistency and comparability of the paleohydrodynamic reconstruction results.

[0102] Table 2 Examples of ancient water depth response function parameter calibration

[0103] parameter illustrate Typical value unit scale factor 0.45 Dimensionless Chemical Environment Regulation Index 0.8–1.2 Dimensionless Deposition energy correction factor 0.3–1.0 Dimensionless Microbial mat integrity index 0.4–0.9 Dimensionless

[0104] Example 7:

[0105] Based on the above embodiments, the process of inputting the actual structural parameters obtained in step three into the ancient quantitative model established in step five, and using a unified normalization mapping and coupled solution algorithm to process the laminar thickness parameters... morphological undulation parameters Lateral extension continuity parameters and microbial mat microstructure index Simultaneous solution is performed to generate continuous output values ​​of paleowater depth. The calculation relationship is as follows:

[0106]

[0107] in, , , , The Cambrian-specific weighting coefficients determined in step five. The basic chemical and paleogeographic integrated environmental parameters obtained in step four are... This is an environmental modulation factor used to suppress the amplification effect of non-depth-controlling factors. This formula achieves a stable mapping of macro- and micro-structural information to a single paleodepth physical quantity, ensuring that the output results have geological comparability and regional consistency.

[0108] The output of the hydrodynamic condition level is based on the paleowater depth value. Composite index of structural disturbance The joint judgment, in which The hydrodynamic energy level is obtained by calculating the spatiotemporal fluctuation amplitude of the structural parameters in step three, and determined by the following discriminant function. :

[0109]

[0110] in, and The scale coefficients are calibrated by the Cambrian quantitative model in step five, with the following symbol: This indicates a floor operation, used to convert continuous calculation results into discrete hydrodynamic levels. This discrimination method enables synchronous constraints between paleodepth control terms and structural disturbance response terms, thereby outputting hydrodynamic condition level results with hierarchical stability.

[0111] Taking a sample from Zhang Xia's group as an example, after normalizing the input parameters: , , , Environmental parameters The ancient water depth was calculated. Structural disturbance index Corresponding hydrodynamic level It belongs to a low-energy stable environment.

[0112] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites, characterized in that, Includes the following steps: Step 1: Collect stromatolite specimens from Cambrian strata and prepare continuous profile samples; Step 2: Use high-resolution 3D imaging technology to scan the sample and obtain its complete macro- and micro-structural digital model; Step 3: Extract the thickness, morphological undulation, lateral extension continuity, and microstructural parameters related to the microbial mat from the digital model; Step 4: Based on geochemical principles and stratigraphic evidence, independently calculate the basic chemical parameters of paleoseawater and regional paleogeographic background parameters during the Cambrian period. Step 5: Based on the exclusive ancient parameters obtained in Step 4, establish a mathematical model for the quantitative relationship between the Cambrian lamellar structure parameters and the ancient water depth and hydrodynamic energy level. Step six: Input the actual structural parameters obtained in step three into the ancient quantitative model established in step five to calculate and output the ancient water depth value and hydrodynamic condition level.

2. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: The process of collecting stromatolite specimens from Cambrian strata and preparing continuous profile samples in step one is further defined as follows: directional sampling is carried out along the vertical growth direction of the same sedimentary sequence; profile samples with constant thickness and undamaged bedding are obtained by continuous cutting according to the macroscopic growth axis of the stromatolite; and the sampling effectiveness is constrained by quantitative criteria for sample continuity, with its continuity index... Calculate according to the following formula: in, Indicates the first The vertical length of a continuous lamellar segment. Indicates the number of striation segments. This represents the total height of a single profile sample. The standard deviation of the lamellar thickness within the profile is represented by this continuity index, which comprehensively characterizes the growth integrity and bedding stability of stromatolites at the sampling scale. This is achieved by controlling... Within the preset threshold range, the prepared continuous profile samples are ensured to maintain the true in-situ growth characteristics in both macroscopic morphology and microscopic laminar structure, thus providing a basic sample with statistical consistency and physical interpretability for subsequent three-dimensional imaging and structural parameter extraction.

3. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: In step two, multi-scale high-resolution 3D imaging technology is used to perform layer-by-layer voxel scanning of continuous cross-sectional samples. By simultaneously acquiring macroscopic layering undulation morphology and microscopic internal structure information of the laminae, a 3D structural digital model under a unified coordinate system is constructed. During the model reconstruction process, a resolution adaptive fusion algorithm is introduced to eliminate geometric distortion caused by imaging at different scales. Specifically, it is constrained by the following structural consistency function: in, Indicates the first Height field of macroscopic laminar interface This represents the local height field of the corresponding micro-layered unit. Represents the spatial gradient operator, The effective number of lamellar layers is used to quantify the consistency between macroscopic fluctuations and microstructure in spatial variation trends, and serves as an optimization target in the 3D reconstruction process. This ensures that the obtained digital model maintains the continuity of macroscopic morphology and the authenticity of microstructure simultaneously, providing a stable and unified structural basis for the subsequent quantitative extraction of lamellar parameters.

4. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: Step three specifically includes constructing a multi-scale structural analysis process based on the three-dimensional macro-micro structural digital model obtained in step two. This involves reconstructing the three-dimensional surface of the stromatolite layer interface and tracing it layer by layer to obtain the normal distance between adjacent layers and form a layer thickness sequence. Simultaneously, spatial gradient calculations are performed on the surface of each layer to quantify its morphological undulation characteristics, and continuous tracing is performed along the main growth direction to characterize lateral extension stability. Furthermore, microstructural parameters are extracted by combining the spatial distribution characteristics of micropores, microfolds, and directional fiber structures within the microbial mat, including the comprehensive structural index of the layers. Calculate as follows: In the formula Indicates the first Layer thickness at each sampling location This indicates the average thickness of the same texture layer. This represents the normalized undulation gradient of the surface of the laminar layer at the corresponding location. This represents the continuity coefficient along the lateral extension direction at that location. The number of sampling points is indicated, and the above structural indices are used to quantify the uniformity of lamellar thickness, the intensity of morphological undulations, and the degree of lateral continuity; at the same time, a parameter for the orderedness of the microbial mat structure is defined. This is used to characterize the response of microstructures to environmental stability, and its calculation method is as follows: in, Indicates the first Characteristic scale of micro-structural units This indicates the angle between its principal orientation and the overall growth normal. The number of microstructure types is indicated by... This method quantitatively reflects the growth directionality of microbial mats and the degree of hydrodynamic disturbance, providing high-resolution structural input parameters for subsequent quantitative inversion of paleowater depth and hydrodynamic conditions.

5. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: The calculation of basic chemical parameters of Cambrian paleoseawater in step four is achieved by jointly inverting the stable isotopic composition and trace element distribution characteristics of syngenetic carbonates in stromatolites, specifically constructing a paleoseawater chemical constraint index. Its expression is: in, and The carbon and oxygen isotope values ​​after correction for diagenetic influences were characterized. Characterizing the ionic composition of seawater during precipitation, this index is used to quantify the saturation state and alkalinity level of the Cambrian seawater carbonate system. The results serve as the chemical boundary condition input for subsequent quantitative models of lamellar structure parameters, thereby avoiding interference from modern seawater parameters in paleoenvironment inversion.

6. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 5, characterized in that: In step four, the regional paleogeographic background parameters are quantitatively coupled with stratigraphic evidence and sedimentary rate inversion results to construct paleogeographic constraint factors. Its expression is: in, and These represent the maximum and minimum burial depths within the same stromatolite sequence. To correspond to the deposition timeframe, The cumulative value of the compaction deformation is used to quantitatively characterize the tectonic stability and relative subsidence rate of the Cambrian basin, and provides an independent paleogeographic scale constraint for establishing the mathematical mapping relationship between the lamellar structure parameters and the paleowater depth and hydrodynamic energy level.

7. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: The quantitative relationship mathematical model established in step five uses the laminar thickness parameters extracted in step three. morphological undulation parameters Lateral extension continuity parameters The paleosea basic chemical parameters obtained in step four After unifying the dimensions, a quantitative response function for paleowater depth is constructed. Its expression is: in, The scale factor is determined based on the paleogeographic background parameters of the Cambrian region. To reflect the moderating index of the influence of paleosea chemical environment on the vertical growth rate of lamellarity, this function couples lamellar geometric features with paleosea chemical conditions to achieve quantitative inversion of the effective water depth when stromatolites are formed. This makes the water depth results directly controlled by observable structural parameters and independently calculated paleoenvironmental parameters, thereby avoiding systematic bias caused by a single morphological index.

8. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 7, characterized in that: The quantitative model of hydrodynamic energy levels in step five is based on the stability of the lamellar structure and the preservation characteristics of the microbial mat, establishing a hydrodynamic index. Its expression is; in, The regional depositional energy correction factor is determined in step four. The integrity index of the mat body is calculated from the microstructure parameters related to the micro-mat. This model quantitatively characterizes the hydrodynamic intensity gradation in the Cambrian sedimentary environment by the response relationship of laminar undulation to shear disturbance and the characterization of continuity to lateral hydrodynamic stability. This ensures that the output hydrodynamic energy level corresponds one-to-one with the actual stress environment during the growth of stromatolites, thereby improving the physical consistency and comparability of the paleohydrodynamic reconstruction results.

9. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: The process of inputting the actual structural parameters obtained in step three into the ancient quantitative model established in step five involves using a unified normalization mapping and coupled solution algorithm to process the laminar thickness parameters. morphological undulation parameters Lateral extension continuity parameters and microbial mat microstructure index Simultaneous solution is performed to generate continuous output values ​​of paleowater depth. The calculation relationship is as follows: in, , , , The Cambrian-specific weighting coefficients determined in step five. The basic chemical and paleogeographic integrated environmental parameters obtained in step four are... This is an environmental modulation factor used to suppress the amplification effect of non-depth-controlling factors. This formula achieves a stable mapping of macro- and micro-structural information to a single paleodepth physical quantity, ensuring that the output results have geological comparability and regional consistency.

10. The method for quantitative reconstruction of paleowater depth and hydrodynamic conditions based on the macro- and micro-structure of Cambrian stromatolites according to claim 1, characterized in that: The output of the hydrodynamic condition level is based on the paleowater depth value. Composite index of structural disturbance The joint judgment, in which The hydrodynamic energy level is obtained by calculating the spatiotemporal fluctuation amplitude of the structural parameters in step three, and determined by the following discriminant function. : in, and The scale coefficients are calibrated by the Cambrian quantitative model in step five, with the following symbol: This indicates a floor operation, used to convert continuous calculation results into discrete hydrodynamic levels. This discrimination method enables synchronous constraints between paleodepth control terms and structural disturbance response terms, thereby outputting hydrodynamic condition level results with hierarchical stability.

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