A method for constructing stratigraphic area-age curves to analyze tectonic evolution

Abstract

This invention relates to the field of geological structural evolution technology, specifically to a method for constructing stratigraphic true area-age curves to analyze structural evolution. The method includes arranging at least four geological interpretation profiles and labeling them with geological age T; constructing an unstructured triangular network between adjacent profiles and summing the true surface areas S; plotting a family of S-T curves; calculating the tectonic deformation rate; and outputting the evolutionary stage sequence, duration, and rate. This invention can quickly and quantitatively complete tectonic evolution analysis. By arranging at least four geological interpretation profiles and constructing an unstructured triangular network between adjacent profiles, this invention uses three-dimensional vector cross accumulation to calculate the true surface area of ​​stratigraphic interfaces. Multiple stratigraphic S-T curves are plotted with geological age as the abscissa and true area as the ordinate to form a family of curves. The tectonic deformation rate is quantitatively calculated from the characteristic segments of the curves, and the tectonic evolution stage sequence, duration, and rate are output, thus enabling rapid tectonic evolution analysis without the need for complex software.

Description

Technical Field

[0001] This invention relates to the field of geological structural evolution technology, specifically to a method for constructing stratigraphic true area-age curves to analyze structural evolution. Background Technology

[0002] Reconstructing the tectonic evolution history of a basin region is a fundamental and crucial task in oil and gas exploration, geological surveys, and geoscientific research. Currently, the commonly used method for tectonic evolution reconstruction in the industry is the balanced profile technique. This method requires geologists to strip and reconstruct faults, folds, etc., layer by layer on the profile based on geomechanical principles to invert the tectonic morphology of different geological periods. Although the results are relatively accurate, this method has significant limitations: 1) The process is complex, heavily reliant on specialized balanced profile software (such as 2DMove, GeoSec, etc.), with cumbersome operation steps and high learning costs; 2) It is time-consuming and labor-intensive, requiring a large amount of manual interpretation and iterative calculation for the reconstruction of each profile, resulting in low efficiency and making it difficult to apply to rapid analysis of large areas; 3) It places high demands on interpreters, as its accuracy largely depends on the interpreter's deep understanding of the regional geological background, fault activity periods and properties, and is highly subjective with a high experience threshold.

[0003] To simplify the process, a simplified judgment method exists in practice: directly inferring the tectonic stress field based on the nature of the fault (normal or reverse fault) and its geological age. For example, identifying a Permian normal fault implies that the Permian period was a extensional period. However, in regions with complex tectonic activity, faults often undergo multiple phases of superimposed alterations of different natures, making it difficult to accurately determine their activity time and final characteristics. This limits the reliability and application scope of this method.

[0004] Therefore, there is an urgent need for a method that does not rely on complex software, does not require detailed interpretation of faults, and can quickly and quantitatively conduct preliminary analysis of tectonic evolution processes, in order to facilitate the rapid establishment of regional tectonic frameworks, the selection of favorable zones, and preliminary geological research. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing a true area-age curve of strata to analyze tectonic evolution, in order to solve the technical problem in the prior art that it is difficult to accurately determine the activity time and the final properties of faults in areas with complex tectonic activity, where faults often undergo multiple phases of superimposed modification with different properties.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0007] A method for constructing stratigraphic area-age curves to analyze tectonic evolution includes the following steps:

[0008] Step 100: Arrange at least four geological interpretation profiles in a grid pattern within the study area, and draw at least three key stratigraphic interfaces on each profile and label them with geological age T; wherein each profile contains a sequence of trajectory points for the same stratigraphic interface, and the trajectory points include the actual length coordinates extending along the stratigraphic interface. ;

[0009] Step 200: Convert the trajectory points on two adjacent cross-sections into three-dimensional spatial coordinates. The trajectory points are connected between two adjacent profiles using an unstructured triangulation method to construct a triangulation covering the stratigraphic interface, and each triangular unit of the triangulation consists of three trajectory points on adjacent profiles.

[0010] Step 300: For each triangular unit, calculate its true surface area using the three-dimensional vector cross product formula, and sum the areas of all triangular units to obtain the true surface area S of the formation interface.

[0011] Step 400: For multiple stratigraphic interfaces, plot a scatter plot with geological age T as the abscissa and actual surface area S as the ordinate and connect the points to form the stratigraphic ST curve of the study area; and perform steps 100-400 on n stratigraphic interfaces of different strata to obtain n stratigraphic ST curves, forming a family of stratigraphic ST curves.

[0012] Step 500: Quantitatively calculate the characteristic segments on each ST curve to obtain the tectonic deformation rate, and conduct a comprehensive analysis of the stratigraphic ST curve family to output the tectonic evolution stage sequence of the study area, and mark the duration and area change rate of each stage as the basis for establishing the regional tectonic framework.

[0013] As a preferred embodiment of the present invention, in step 100, the number of geological interpretation profiles arranged in a grid pattern within the study area is m, where m ≥ 4, and the profile spacing scale is set to 5-20 km.

[0014] In a preferred embodiment of the present invention, in step 100, the apparent length of the stratigraphic interface is measured along its actual distribution trajectory, and then converted into an actual length coordinate sequence according to the map scale. ;

[0015] Furthermore, when the stratigraphic interface is missing due to later erosion, the trajectory of the eroded area is restored by trend extrapolation based on the attitude trends of the upper and lower adjacent strata, and the reliability level of the restored segment is marked.

[0016] Alternatively, when the stratigraphic interface is dissected by a fault, the length coordinate sequence of the interface on both sides of the fault can be measured separately, and the displacement can be marked at the fault point.

[0017] In a preferred embodiment of the present invention, in step 200, a three-dimensional triangulation network of the same stratigraphic interface between two adjacent cross sections is established, and the trajectory points of the stratigraphic interface on the adjacent cross sections are converted into three-dimensional coordinates. ,in The coordinates are perpendicular to the cross-sectional direction;

[0018] In one of the cross sections, the first The point and its adjacent profiles Triangular units are established between points, and unstructured triangular networks are used to connect the trajectory points of adjacent profiles to ensure that the triangular units conform to the changes in stratigraphic attitude.

[0019] As a preferred embodiment of the present invention, in step 200, the unstructured triangulation method is a constrained Delaunay triangulation method, including:

[0020] Merge the trajectory points on two adjacent cross-sections into a three-dimensional point set;

[0021] Construct an initial triangulation network that satisfies the empty circumcircle criterion;

[0022] Maximize the minimum interior angle of the triangle through local optimization using LOP;

[0023] Fault lines are embedded into the triangular mesh as forced constraint edges;

[0024] Delete inferior triangles with interior angles less than 30° or greater than 120° and re-subdivide them.

[0025] In a preferred embodiment of the present invention, in step 300, the formula for calculating the true surface area of ​​each triangular unit using the three-dimensional vector cross product is as follows:

[0026] ;

[0027] in, , Let the vectors be the two sides of the triangle;

[0028] By summing the areas of all triangular pieces, we can obtain the true distribution area S of the stratigraphic interface at geological age T.

[0029] In a preferred embodiment of the present invention, step 400, the division of the formation ST curve stage, includes:

[0030] Horizontal segment, i.e., slope This is the period of structural stability;

[0031] Ascending segment, i.e., slope This is the period of structural tension;

[0032] The descending segment, i.e., the slope This is the period of structural compression.

[0033] As a preferred embodiment of the present invention, in step 500, the formula for quantitatively calculating the characteristic line segments on the formation ST curve is as follows:

[0034] Tensioning rate: ;

[0035] Extrusion rate: ;

[0036] Area change rate: ;

[0037] in, , The area between the two endpoints of the characteristic line segment is denoted as . , This corresponds to the geological era.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] This invention arranges at least four geological interpretation profiles and constructs an unstructured triangular network between adjacent profiles. It uses three-dimensional vector cross accumulation to calculate the true surface area of ​​stratigraphic interfaces. Multiple stratigraphic ST curves are drawn to form a family of curves with geological age as the abscissa and true area as the ordinate. The tectonic deformation rate is obtained by quantitatively calculating the characteristic line segments of the curves. The sequence of tectonic evolution stages, duration, and rate are output, thereby completing the tectonic evolution analysis quickly without the need for complex software.

[0040] Furthermore, by constructing unstructured triangular meshes between adjacent profiles, the triangular meshes can be back-fitted to the attitude changes of the stratigraphic interface, achieving the matching of the total area of ​​multiple triangular mesh units with the area of ​​the stratigraphic interface. Thus, the true surface area of ​​the stratigraphic interface can be calculated by accumulating and adding three-dimensional vector crosses, overcoming the defects of the longitudinal and transverse profile multiplication method which fabricates geometric area and the results are affected by the profile strike. It is suitable for oblique structural belts or complex fold-thrust belts. Attached Figure Description

[0041] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0042] Figure 1 A flowchart illustrating a method for constructing stratigraphic true area-age curves to analyze tectonic evolution, provided in an embodiment of the present invention;

[0043] Figure 2This is a schematic diagram of a multi-section grid arrangement for a method of constructing stratigraphic true area-age curves to analyze tectonic evolution, provided in an embodiment of the present invention.

[0044] Figure 3 A schematic diagram of the triangular mesh interpolation principle for a method of constructing stratigraphic true area-age curves to analyze tectonic evolution provided in an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of a single-interface ST curve for a method of constructing a true area-age curve of strata to analyze tectonic evolution, provided in an embodiment of the present invention. Detailed Implementation

[0046] 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.

[0047] like Figure 1 As shown, this invention provides a method for constructing stratigraphic area-age curves to analyze tectonic evolution. Taking a dipping compressional basin as an example (the angle between the tectonic strike and the main profile is approximately 30°), the method of this invention is applied to perform tectonic evolution analysis. The method includes the following steps:

[0048] Step 100: Arrange at least four geological interpretation profiles in a grid pattern within the study area, and draw at least three key stratigraphic interfaces on each profile and label them with geological age T; wherein each profile contains a sequence of trajectory points for the same stratigraphic interface, and the trajectory points include the actual length coordinates extending along the stratigraphic interface. .

[0049] Within the study area, there are m geological interpretation profiles arranged in a grid pattern, with m ≥ 4, and the profile spacing is set at 5-20 km. The profile orientation should be orthogonal grid-like to control for changes in structural strike.

[0050] Furthermore, in drawing software (such as Surfer, GoCAD, GeoMap or AutoCAD), depict the n key stratigraphic interfaces on each section (n≥3, covering different structural layers, such as basement, major unconformity, stratigraphic interfaces, etc.), and mark the age T (unit: Ma) of each geological interface.

[0051] Among them, for each stratigraphic interface on each cross section:

[0052] The apparent length of the stratigraphic boundary was measured along its actual distribution trajectory and converted into an actual length coordinate sequence based on the map scale. ;

[0053] Furthermore, when the interface is lost due to later erosion, the trajectory of the eroded area is restored by trend extrapolation based on the attitude trends of the upper and lower adjacent strata, and the reliability level of the restored segment is marked (high / medium / low).

[0054] Alternatively, when the interface is dissected by a fault, measure the length coordinate sequence of the interface on both sides of the fault and mark the displacement at the break point.

[0055] Specifically:

[0056] Five grid-like seismic geological profiles (spaced 10 km apart, trending NE-SW) were constructed within the study area, covering a width of 40 km. The upper boundary of the Jurassic strata was selected. ), Lower Cretaceous top boundary ( ), Upper Cretaceous top boundary ( ), the top boundary of the Paleogene system ( Four key stratigraphic interfaces. The trajectory point sequence of these four interfaces is depicted on each profile, and the geological age T of each interface is identified. 145Ma 100.5 Ma :66Ma, :23Ma).

[0057] On section P1, Current interface length Due to the loss of the middle section due to later erosion, the paleolength was restored using the trend extrapolation method based on the attitude trends of the two flanks. Similar measurements were taken of the P2-P5 profile.

[0058] Trend extrapolation method:

[0059] Let the coordinates of the interface endpoints of the measured sections on both sides of the erosion zone be... and The width of the eroded area is ,but:

[0060] ;

[0061] ;

[0062] in, This is a predicted value;

[0063] The slope represents the strength and direction of the trend. A positive value indicates an upward trend; if... A negative value indicates a downward trend;

[0064] The intercept represents the starting position of the time series on the time axis.

[0065] Step 200: Convert the trajectory points on two adjacent cross-sections into three-dimensional spatial coordinates. The trajectory points are connected between two adjacent profiles using an unstructured triangulation method to construct a triangulation network covering the stratigraphic interface. Each triangular unit of the triangulation network consists of three trajectory points from adjacent profiles.

[0066] Specifically:

[0067] Establish a three-dimensional triangulation network of the same stratigraphic interface between two adjacent cross sections, and convert the trajectory points of the stratigraphic interface on the adjacent cross sections into three-dimensional coordinates. ,in, The coordinates are perpendicular to the cross-sectional direction;

[0068] In one of the cross sections, the first The point and its adjacent profiles Triangular units are established between points, and unstructured triangular meshes are used to connect the trajectory points of adjacent profiles, so that the triangular units conform to the changes in stratigraphic attitude.

[0069] In this study area, a right-handed coordinate system is used, with the positive X-axis direction representing the main trend of the profile (usually chosen as the structural trend or due east).

[0070] 1. Determine the spatial location of the cross-section

[0071] Each section on the plan starts from a starting point. and the end point definition;

[0072] Calculate the azimuth of the profile strike. :

[0073] ;

[0074] 2. Determine the Y-coordinate (distance perpendicular to the main profile direction).

[0075] Taking the first profile P1 as the reference (Y1=0), the Y coordinates of the remaining profiles Pi are:

[0076] ;

[0077] in, For the first The plane coordinates of the midpoint of the section. Let P1 be the azimuth angle of its direction.

[0078] Simplified case (when the cross-sections are approximately parallel and perpendicular to the structural orientation):

[0079] If the cross-sections are arranged at equal intervals perpendicular to the structural trend, with a spacing of D, then:

[0080] , .

[0081] The structured triangulation method employs the constrained Delaunay triangulation method.

[0082] Criterion: In the triangular network constructed from the point set between the cross sections, the circumcircle of any triangle does not contain any other points (empty circumcircle criterion), and the minimum interior angle of the triangle is maximized.

[0083] Implementation steps:

[0084] 1. Discrete point set generation: Merge trajectory points on two adjacent cross-sections into a three-dimensional point set. ;

[0085] 2. Initial triangulation: Using the lines connecting the nearest neighbor pairs as initial edges, construct initial triangles that satisfy the Delaunay criterion;

[0086] 3. LOP (Local Optimization Procedure): Perform a flip test on the common edge of adjacent triangles. If the minimum interior angle increases after flipping, then perform the flip.

[0087] 4. Constraint Embedding: Fault lines and boundary lines are embedded into the triangular mesh as forced constraint edges to ensure that the triangular pieces do not cross faults;

[0088] 5. Quality inspection: Delete inferior triangles with interior angles less than 30° or greater than 120°, and insert auxiliary points in the relevant areas to re-subdivide.

[0089] Specifically, suppose there is a sequence of trajectory points for stratigraphic interfaces on adjacent profiles Pa and Pb:

[0090] Pa: ;

[0091] Pb: ;

[0092] Convert each point to three-dimensional coordinates: → , → ;

[0093] in, , The coordinates of the cross-section in the vertical direction are given.

[0094] Nearest neighbor matching: for each point on Pa Find the point in Pb with the closest Euclidean distance. As a matching point:

[0095] ;

[0096] Triangular network topology construction (wavefront spread algorithm)

[0097] 1. Initial triangle: - - Form the first triangle ( The nearest neighbor is , for (Successor point along the profile).

[0098] 2. Wavefront Extension: Using the sides of the constructed triangle as "wavefronts," extend the wavefront to the uncovered area:

[0099] against the wavefront Find the best matching point to expand the new triangle;

[0100] Prioritize selecting the point that maximizes the expansion angle and minimizes the change in the normal vector;

[0101] Ensure that the new triangles do not overlap with or have gaps with the existing triangulation network.

[0102] 3. Topological constraints:

[0103] The interior angles of a triangle should be controlled between 30° and 120° to avoid unbalanced triangles.

[0104] Automatic densification at the fold transition points (curvature) (Time interval halved)

[0105] Forced segmentation at faults: triangular sections are constructed without crossing faults, and networks are built on the hanging wall and footwall respectively, with subsequent accumulation.

[0106] by Taking the interface as an example, a triangular mesh is established between adjacent cross-sections P1 and P2:

[0107] Set the coordinates of point P1 nearest neighbor on P2 The points and adjacent points form a triangle.

[0108] Step 300: For each triangular unit, calculate its true surface area using the three-dimensional vector cross product formula, and sum the areas of all triangular units to obtain the true surface area S of the formation interface.

[0109] Among them, the actual area calculation of a single triangular piece is as follows:

[0110] For triangle vertex A B C :

[0111] 1. Construct edge vectors:

[0112] ;

[0113] ;

[0114] in, , Let the vectors be the two sides of the triangle;

[0115] 2. Calculate the cross product (normal vector):

[0116] ;

[0117] 3. True surface area:

[0118] ;

[0119] Accumulated across all interfaces:

[0120] ;

[0121] in, The number of sections, For the first The number of triangular pieces in each cross section.

[0122] Specifically, for each triangular unit, the formula is used. Calculate the actual area (considering the angle of inclination) , Therefore, the actual area > the projected area. Adding up all the triangular pieces between the 5 sections, we get... Actual total area of ​​the interface Similar to calculating the area of ​​other interfaces: , , .

[0123] In steps 100-300, the true surface area of ​​the stratigraphic interface is calculated based on multi-section triangular mesh interpolation. By constructing a three-dimensional triangular mesh between adjacent sections, the true surface area containing dip angle information is obtained by using vector cross product. This fundamentally solves the systematic errors caused by the fictitious geometric area in the existing "longitudinal and transverse section multiplication method" and the neglect of stratigraphic dip angle in the "projected area method".

[0124] And in the above methods:

[0125] X: The horizontal distance along the profile direction; determined by the measured horizontal projection distance along the interface trajectory from the profile starting point; the data is obtained from the profile drawing measured to scale.

[0126] Z: Elevation or burial depth; determined by the vertical coordinates (elevation or subsurface depth) on the profile; data sourced from seismic interpretation or measured profiles.

[0127] Y: The coordinate perpendicular to the profile direction; determined by the geographical location of the profile; the data comes from GPS coordinates or survey network coordinates.

[0128] Step 400: For multiple stratigraphic interfaces, plot a scatter plot with geological age T as the abscissa and actual surface area S as the ordinate and connect the points to form the stratigraphic ST curve of the study area; and perform steps 100-400 on n stratigraphic interfaces of different strata to obtain n stratigraphic ST curves, forming a family of stratigraphic ST curves.

[0129] The ST curve stage division includes:

[0130] Horizontal segment, i.e., slope This is the period of structural stability;

[0131] Ascending segment, i.e., slope This is the period of structural tension;

[0132] The descending segment, i.e., the slope This is the period of structural compression.

[0133] Specifically:

[0134] Plotting geological age T on the x-axis and actual area S on the y-axis, , , , Four ST curves.

[0135] Based on the above calculations: → (Increase) → (Decrease) → (Continuously decreasing);

[0136] Plotting four curves reveals the following: - All segments increased (100% consistency). - Three lines rise and one line falls ( (localized severe erosion of the interface) - All segments decreased (100% consistency).

[0137] Determination: Early Cretaceous ( - This period represents a regional extensional phase, from the Late Cretaceous to the Paleogene ( - This is the period of regional compression. - There are localized differences in rises and falls during the transition period.

[0138] Step 500: Quantitatively calculate the characteristic segments on each ST curve to obtain the tectonic deformation rate, and conduct a comprehensive analysis of the stratigraphic ST curve family to output the tectonic evolution stage sequence of the study area, and mark the duration and area change rate of each stage as the basis for establishing the regional tectonic framework.

[0139] The formula for quantitatively calculating the characteristic line segments on the ST curve of the formation is as follows:

[0140] Tensioning rate: ;

[0141] Extrusion rate: ;

[0142] Area change rate: ;

[0143] in, , The area between the two endpoints of the characteristic line segment is denoted as . , This corresponds to the geological era.

[0144] Specifically:

[0145] Tension period ( - Area change rate:

[0146] ;

[0147] Squeeze period ( - Area change rate:

[0148] .

[0149] Output the tectonic evolution stage sequence of the study area: Early Cretaceous extensional period (area increase rate) → Late Cretaceous transition period (local differential rise and fall) → Paleogene compression period (rate of area reduction) ).

[0150] The above method is applicable to the rapid analysis of the tectonic evolution of oblique tectonic belts or complex fold-thrust belts, and is particularly suitable for the establishment of regional tectonic frameworks in the early stages of exploration when three-dimensional tectonic reconstruction software is lacking.

[0151] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A method for constructing stratigraphic true area-age curves to analyze tectonic evolution, characterized in that, Includes the following steps: Step 100: Arrange at least four geological interpretation profiles in a grid pattern within the study area, and draw at least three key stratigraphic interfaces on each profile and label them with geological age T; wherein each profile contains a sequence of trajectory points for the same stratigraphic interface, and the trajectory points include the actual length coordinates extending along the stratigraphic interface. ; Step 200: Convert the trajectory points on two adjacent cross-sections into three-dimensional spatial coordinates. The trajectory points are connected between two adjacent profiles using an unstructured triangulation method to construct a triangulation covering the stratigraphic interface, and each triangular unit of the triangulation consists of three trajectory points on adjacent profiles. Step 300: For each triangular unit, calculate its true surface area using the three-dimensional vector cross product formula, and sum the areas of all triangular units to obtain the true surface area S of the formation interface. Step 400: For multiple stratigraphic interfaces, plot a scatter plot with geological age T as the abscissa and actual surface area S as the ordinate and connect the points to form the stratigraphic ST curve of the study area; and perform steps 100-400 on n stratigraphic interfaces of different strata to obtain n stratigraphic ST curves, forming a family of stratigraphic ST curves. Step 500: Quantitatively calculate the characteristic segments on each ST curve to obtain the tectonic deformation rate, and conduct a comprehensive analysis of the stratigraphic ST curve family to output the tectonic evolution stage sequence of the study area, and mark the duration and area change rate of each stage as the basis for establishing the regional tectonic framework.

2. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 100, there are m geological interpretation profiles arranged in a grid pattern within the study area, where m ≥ 4, and the profile spacing scale is set to 5-20 km.

3. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 100, the apparent length of the stratigraphic interface is measured along its actual distribution trajectory, and converted into an actual length coordinate sequence according to the map scale. ; Furthermore, when the stratigraphic interface is missing due to later erosion, the trajectory of the eroded area is restored by trend extrapolation based on the attitude trends of the upper and lower adjacent strata, and the reliability level of the restored segment is marked. Alternatively, when the stratigraphic interface is dissected by a fault, the length coordinate sequence of the interface on both sides of the fault can be measured separately, and the displacement can be marked at the fault point.

4. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 200, a three-dimensional triangulation network of the same stratigraphic interface between two adjacent cross-sections is established, and the trajectory points of the stratigraphic interface on the adjacent cross-sections are converted into three-dimensional coordinates. ,in The coordinates are perpendicular to the cross-sectional direction; In one of the cross sections, the first The point and its adjacent profiles Triangular units are established between points, and unstructured triangular networks are used to connect the trajectory points of adjacent profiles to ensure that the triangular units conform to the changes in stratigraphic attitude.

5. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 200, the unstructured triangulation method is a constrained Delaunay triangulation method, including: Merge the trajectory points on two adjacent cross-sections into a three-dimensional point set; Construct an initial triangulation network that satisfies the empty circumcircle criterion; Maximize the minimum interior angle of the triangle through local optimization using LOP; Fault lines are embedded into the triangular mesh as forced constraint edges; Delete inferior triangles with interior angles less than 30° or greater than 120° and re-subdivide them.

6. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 300, for each triangular unit, the formula for calculating its true surface area using the three-dimensional vector cross product is as follows: ； in, , Let the vectors be the two sides of the triangle; By summing the areas of all triangular pieces, we obtain the true distribution area S of the stratigraphic interface at geological age T.

7. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 1, characterized in that, In step 400, the formation ST curve stage division includes: Horizontal segment, i.e., slope This is the period of structural stability; The rising segment, i.e., the slope This is the period of structural tension; The descending segment, i.e., the slope This is the period of structural compression.

8. The method for constructing stratigraphic true area-age curves to analyze tectonic evolution according to claim 7, characterized in that, In step 500, the formula for quantitatively calculating the characteristic line segments on the formation ST curve is as follows: Tensioning rate: ; Extrusion rate: ; Area change rate: ; in, , The area between the two endpoints of the characteristic line segment is denoted as . , This corresponds to the geological era.

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