Simulation experiment device and method for separation of metamorphic nuclear miscellaneous rock

Abstract

The invention relates to a metamorphic nuclear miscellaneous rock detachment simulation experiment device and method.The device comprises a supporting platform and a plurality of experiment elements which are combined to form experiment modules, and the first experiment module comprises a driving assembly provided with a movable plate, a first surrounding assembly and a first movable baffle and is used for constructing a first surrounding area; the first movable baffle can move and is arranged opposite to the movable plate; the second experiment module comprises the driving assembly, a second surrounding assembly and a second fixed baffle and is used for constructing a second surrounding area; the movable plate is opposite to the second fixed baffle and can move; the third experiment module comprises the driving assembly, a third surrounding assembly and a third movable baffle and is used for constructing a third surrounding area; the stretching direction of the driving assembly is perpendicular to the moving direction of the third moving baffle. The device adopts a modular design, and supports rapid switching of three groups of experiment modes of free gravity stretching, constant-rate stretching and different-direction stretching superposition.

Description

Technical Field

[0001] This invention relates to the field of structural geological physical simulation technology, and in particular to an experimental apparatus and method for simulating the separation of metamorphic core complexes. Background Technology

[0002] Metamorphic core complexes are an important manifestation of lithospheric extensional tectonics, and their formation and evolution are often accompanied by complex stress field changes and deep thermodynamic processes. In the field of oil and gas exploration, a deep understanding of the detachment mechanism of metamorphic core complexes is crucial for revealing the evolutionary patterns of rift basins.

[0003] Currently, traditional sandbox simulation experiments have some limitations when studying this type of structure: traditional devices can usually only achieve tension or compression in a single direction, and cannot reproduce the dynamic rotation of stress fields and multi-stage anisotropic superposition processes commonly found in nature; fixed experimental devices are difficult to adapt to the requirements of anisotropic stress superposition.

[0004] Since existing technologies have not effectively solved the above problems, the accuracy and reliability of tectonic physical simulation in the study of complex basin evolution are severely limited. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a simulation experimental device and method for the separation of metamorphic core complexes.

[0006] The technical solution adopted by the present invention to solve its technical problem is: to construct a metamorphic core complex dismantling simulation experimental device, including a support platform and experimental elements for being set on the support platform; The experimental components include a driving assembly, a first enclosure assembly, a second enclosure assembly, a third enclosure assembly, a first movable baffle, a second fixed baffle, and a third movable baffle; the driving assembly includes a driving element and a movable plate connected thereto, the movable plate being used to cooperate in forming an enclosure area and being able to move in a straight line under the drive of the driving element; This experimental setup, through the combination and configuration of different experimental components, can be switched to form any of the following three experimental modules: The first experimental module includes a driving component, a first enclosure component, and a first movable baffle for constructing a first enclosure area; the first movable baffle is disposed opposite to the movable plate and is configured to move outward under the force of gravity. The second experimental module includes a driving component, a second enclosure component, and a second fixed baffle, used to construct a second enclosure area; the movable plate is disposed opposite to the second fixed baffle, and the driving component is configured to drive the movable plate to move at a preset rate; The third experimental module includes a driving component, a third enclosure component, and a third movable baffle, used to construct a third enclosure area; wherein, the third movable baffle module is configured to move outward under the action of gravity, the movable baffle is configured to move outward at a preset speed under the drive component, and the moving direction of the movable baffle is perpendicular to the moving direction of the third movable baffle.

[0007] In some embodiments, the support platform is a polished metal base; pulley assemblies are installed at the bottom of both the first and third movable baffles.

[0008] In some embodiments, the first enclosure component includes a plurality of transparent tempered glass pieces, which together with the first movable baffle and the movable plate form a square structure; The second enclosure component includes several pieces of transparent tempered glass, which together with the second fixed baffle and the movable plate form a square structure; The third enclosure component includes several transparent acrylic panels, which together with the third movable baffle and the movable plate form a right-angled trapezoidal structure; wherein, the third movable baffle has an inclined side to form the hypotenuse of the right-angled trapezoidal structure.

[0009] In some embodiments, the third enclosure assembly includes a plurality of enclosure panels erected on a support platform, including a first enclosure panel, a second enclosure panel, and a third enclosure panel; In the third experimental module, the first enclosure and the second enclosure are vertically connected, and the surface of the first enclosure is parallel to the stretching direction of the drive assembly in space; the third enclosure is parallel to the first enclosure and has a gap with the second enclosure; the movable plate is located between the third enclosure and the first enclosure and is set parallel to the second enclosure; the third movable baffle is a right-angled triangle structure, inserted from the opposite side of the first enclosure into the space between the third enclosure and the second enclosure, and the hypotenuse of the third movable baffle is used to form the boundary of the third enclosure area.

[0010] In some embodiments, the angle between the hypotenuse and the long right-angle side of the third movable baffle is 30°-60°.

[0011] This invention also constructs a method for simulating the dismantling of metamorphic core complexes. This method is implemented using the aforementioned simulation apparatus for the dismantling of metamorphic core complexes, and includes the following steps: Free gravity stretching experiment steps: Construct the first enclosure area using the first experimental module, lay experimental materials to form a base layer and a brittle layer, and allow the first moving baffle to slide outward under the gravitational potential energy of the experimental materials; conduct multiple sets of observation experiments to screen out the optimal stretching rate. The constant rate tensile test procedure is as follows: a second enclosure area is constructed using the second experimental module, experimental materials are laid to form a base layer and a brittle layer, and whether the base layer contains a viscous medium is used as a control variable. Then, the movable plate is controlled to stretch the experimental material at the optimal stretching rate. By comparing the changes in the dip angle of the detachment fault in the two sets of experiments, the influence of the rheological anomaly on the formation of the metamorphic core complex is determined. Anisotropic stretching superposition experiment steps: The third enclosure area is constructed using the third experimental module, experimental materials are laid to form a base layer and a brittle layer, and a viscous medium is embedded in the base layer. Then, the third moving baffle slides outward under gravity and the movable plate is mechanically stretched outward at the optimal stretching rate to simulate the stress field rotation and non-coaxial deformation process, thereby obtaining experimental results.

[0012] In some embodiments, the free gravity stretching experiment steps specifically include: The first set of experimental materials is provided, which includes a substrate material and a brittle material; The first experimental module was constructed by combining the components. A base material is uniformly laid as a base layer in the first enclosure area, and a granular material is laid on top of it as a brittle layer. Release the limiting position of the first movable baffle, allowing it to move away from the movable plate under the influence of the material's gravity; Control the moving distance of the first moving baffle, and after each moving phase, lay the same deposited granular material, repeating this process several times; By comparing multiple sets of experiments, the experimental group whose construction style best matched the preset prototype was selected, and its stretching rate was determined as the optimal stretching rate for subsequent experiments.

[0013] In some embodiments, the constant rate tensile test procedure specifically includes: A second set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies; the viscosity of the viscous medium is lower than that of the substrate material. Combine and construct the second experimental module; A base material and a brittle material are added to the second enclosure region to construct a base layer and a brittle layer, and a viscous medium is embedded in a predetermined position in the base layer as an experimental variable; Control the moving plate to continuously stretch the material at the optimal stretching rate; A control group without embedded viscous medium was set up, and the difference in the dip angle evolution of the detachment fault in the two groups of experiments was recorded to confirm the role of the rheological anomaly.

[0014] In some embodiments, the anisotropic stretching superposition experimental steps specifically include: A third set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies; the viscosity of the viscous medium is lower than that of the substrate material. Combine and construct the third experimental module; A base layer is laid in the third enclosure area, and an etched groove is set at a preset position on the base layer and a viscous medium is poured in. The stress was applied in three stages: in the first stage, the limit of the third moving baffle was released, allowing it to extend to the first preset length under the action of gravity in a controlled manner; in the second stage, the moving plate was controlled to stretch to the second preset length at the optimal stretching rate; and in the third stage, the moving plate was kept stretched to the third preset length, thereby obtaining the experimental results.

[0015] In some embodiments, the substrate material is selected as silica gel with a viscosity of 5000 Pa·s and a thickness of 8 cm; several etched grooves are arranged, all of which are long strips and are intermittently embedded on the substrate layer along the moving direction of the third moving baffle; the viscous medium is selected as silica gel with a viscosity of 2000 Pa·s; the brittle material is selected as quartz sand of 40-70 mesh or 80-120 mesh; the brittle layer is laid in layers, with the thickness of each layer controlled at 10±0.5 mm, and mineral dyes are added between the layers as time markers; In the three-stage stress application, the third moving baffle in the first stage stretches by 5cm, the movable plate in the second stage stretches by 9cm at a constant rate of 0.1cm / min, and the movable plate in the third stage maintains a continuous stretch of 4cm.

[0016] The implementation of this invention has the following beneficial effects: The metamorphic core complex detachment simulation experimental device of this invention adopts a modular design and supports rapid switching of three experimental modes. The experimental modes include three sets of experiments: free gravity extension, constant rate extension, and superposition of anisotropic extension. It effectively solves the technical defects of traditional sand box simulation of single extension and difficulty in simulating superposition of anisotropic stress, and provides a more accurate experimental means for the study of rift basin tectonic evolution. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic diagram of the structure of the first experimental module of the present invention in some embodiments; Figure 2 This is a schematic diagram of the structure of the second experimental module of the present invention in some embodiments; Figure 3 This is a schematic diagram of the structure of the third experimental module of the present invention in some embodiments; Figure 4 yes Figure 3 The diagram shows the structure of the third experimental module from a top-down perspective; Figure 5This is a schematic diagram of the structure of the first movable baffle of the metamorphic core complex dismantling simulation experimental device of the present invention; Figure 6 This is a schematic diagram of the structure of the third movable baffle of the metamorphic core complex dismantling simulation experimental device of the present invention.

[0018] Figure label: Support platform 1; drive assembly 2; drive component 21; connecting shaft 22; movable plate 23; first enclosure assembly 3; second enclosure assembly 4; third enclosure assembly 5; first enclosure plate 51; second enclosure plate 52; third enclosure plate 53; first movable baffle 6; baffle body 61; first support foot 62; first pulley assembly 63; connecting rib 64; second fixed baffle 7; third movable baffle 8; inclined side 81; third support foot 82; third pulley assembly 83; etched groove 9. Detailed Implementation

[0019] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0020] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0022] This invention provides a simulation experimental device for the detachment of metamorphic core complexes, which aims to accurately reconstruct the tectonic evolution process of rift basins by flexibly switching between three modes: free gravity stretching, constant rate stretching, and superposition of anisotropic stretching, combined with the simulation of local rheological anomalies.

[0023] Please refer to Figures 1-3 The metamorphic core complex dismantling simulation experimental device mainly includes: a support platform 1, and experimental elements for setting on the support platform 1; the experimental elements include a drive component 2, a first enclosure component 3, a second enclosure component 4 and a third enclosure component 5; the drive component 2 includes a drive element 21 and a movable plate 23 connected thereto, the movable plate 23 is used to cooperate to form an enclosure area and can move linearly. This experimental setup combines different experimental elements to form one of the following three experimental modules: See Figure 1 The first experimental module includes a driving component 2, a first enclosure component 3, and a first movable baffle 6, used to construct a first enclosure area for conducting a free gravity extension experiment; the first movable baffle 6 is arranged opposite to the movable plate 23, and the first movable baffle 6 is configured to move outward under gravity drive. See Figure 2 The second experimental module includes a driving component 2, a second enclosure component 4, and a second fixed baffle 7, used to construct a second enclosure area for a constant-rate tensile test; the movable plate 23 is arranged opposite to the second fixed baffle 7, and the driving component 2 is configured to stretch outward at a preset rate; See Figure 3 The third experimental module includes a driving component 2, a third enclosure component 5, and a third movable baffle 8, used to construct a third enclosure area for conducting anisotropic extension and superposition experiments; the third movable baffle 8 has an inclined side 81 for forming a non-rectangular enclosure area, and the third movable baffle 8 is configured to move outward under gravity; the stretching direction of the driving component 2 is perpendicular to the moving direction of the third movable baffle 8.

[0024] Understandably, in the free gravity stretching experiment, a basal layer and a brittle layer are constructed using experimental materials in the first enclosed region, causing the first moving baffle 6 to slide outward under the gravitational potential energy of the experimental materials, thus simulating the thermogravimetric diffusion of the lithosphere. By adding experimental materials periodically and controlling the moving distance of the first moving baffle 6, the strain rate decay law is recorded. Based on this, multiple sets of observation experiments are conducted to screen out the optimal stretching rate. It is worth noting here that "outward" mentioned in the context can be understood as towards the outside of the supporting platform 1.

[0025] In a constant-rate tensile test, a basement layer and a brittle layer were constructed using experimental materials in a second enclosed region. The movable plate 23 was continuously stretched at the optimal stretching rate, i.e., its outward movement was controlled. The experiment incorporated a viscous medium embedded in the basement layer as a variable, and a control group was set up. By observing the difference in the dip angle of the detachment fault in the two groups, the deep-seated influence of local crustal rheological anomalies on the formation of metamorphic core complexes was explored. It should be noted that current models often assume a homogeneous basement and do not fully consider the control mechanisms of local rheological anomalies such as magma intrusion and basement weak zones on the geometry and kinematics of detachment faults. This invention, by incorporating a viscous medium to simulate rheological anomalies, has a positive effect on the study of rift basin tectonic evolution.

[0026] In the anisotropic extension superposition experiment, a base layer and a brittle layer are constructed in the third enclosed region using experimental materials, and a viscous medium is embedded in the base layer. The experiment achieves the spatiotemporal superposition of stresses in different directions by sliding outward under gravity of the third moving baffle 8 and mechanically stretching outward by the movable plate 23, thereby simulating the process of stress field rotation and non-coaxial deformation.

[0027] Further, see Figure 1 The support platform 1 can be a circular metal base (such as a steel plate) with a high-precision polished surface to reduce bottom friction during the experiment.

[0028] The drive component 21 of the drive assembly 2 can be a stepper motor, and a connecting shaft 22 connects it to the movable plate 23. The movable plate 23 is driven by the motor, enabling precise displacement control.

[0029] The first enclosure component 3 includes several transparent tempered glass panels, which are configured to be fixed at intervals (e.g., by screws and clamping bases) to the support platform 1, forming a straight channel. Tempered glass is chosen because of its high strength properties, which can withstand the lateral pressure of the experimental materials while providing a clear lateral cross-sectional observation window.

[0030] The first movable baffle 6 and the movable plate 23 are disposed between the transparent tempered glass plates, wherein the sides of the first movable baffle 6 and the movable plate 23 are in contact with the transparent tempered glass plates. The first movable baffle 6 includes a baffle body 61, a first support foot 62, and a first pulley assembly 63 mounted on the first support foot 62. The first pulley assembly 63 serves as a friction-reducing mechanism to reduce sliding friction.

[0031] See Figure 5 The first movable baffle 6 may include a first baffle body 61 and two first support feet 62 on the outer side. The first support feet 62 are connected to the baffle body 61 by connecting ribs 64. Each first support foot 62 is equipped with a set of first pulley assemblies 63 (e.g., four pulleys arranged at axial intervals). This arrangement is because the pulley assembly converts sliding friction into rolling friction, greatly reducing the resistance when the baffle moves, ensuring that the movement of the baffle is purely driven by the gravitational potential energy of the experimental material, rather than overcoming the friction of the device, thereby simulating the diffusion process of the lithosphere due to the gravitational gradient.

[0032] It should be noted that the frictional resistance of the sidewalls in current experimental setups often leads to edge stress concentration, distorting the extension process and failing to accurately simulate the free extension response under natural gravity. Here, the pulley assembly and smooth tempered glass plate effectively reduce the error in the free gravity response caused by boundary disturbances. The third experimental module below uses a similar construction.

[0033] See Figure 2 The second enclosure component 4 includes several transparent tempered glass panels, which are fixed to the support platform 1 at intervals to form a straight channel. The second fixed baffle 7 serves as a fixed boundary and is disposed between the transparent tempered glass panels and is arranged opposite to each other; wherein the sides of the second fixed baffle 7 and the movable plate 23 are in contact with the transparent tempered glass panels.

[0034] See Figure 3 The third enclosure component 5 includes multiple enclosure panels configured to stand fixedly (e.g., by hinges) on the support platform 1, forming a frame with the movable plate 23; a third movable baffle 8 can be inserted from one end of the frame, and its inclined side 81 forms the boundary of the third enclosure area. It can be further noted that acrylic sheets can be used for the enclosure panels because they are easy to install and facilitate the construction of complex boundary conditions and overhead observation required for heterogeneous experiments.

[0035] In the illustrated embodiment, such as Figure 3As shown, the third enclosure component 5 includes three enclosure panels, each standing on the support platform 1, namely a first enclosure panel 51, a second enclosure panel 52, and a third enclosure panel 53. The first enclosure panel 51 and the second enclosure panel 52 are vertically connected, and the surface of the first enclosure panel 51 is spatially parallel to the stretching direction of the drive component 2. The third enclosure panel 53 is parallel to the first enclosure panel 51 and spaced apart. A movable plate 23 is located between the third enclosure panel 53 and the first enclosure panel 51, and is parallel to the second enclosure panel 52. After the third movable baffle 8 is inserted, a right-angled trapezoidal enclosure area is formed. The movable plate 23 can serve as the shorter side of the right-angled trapezoid, and the inclined side 81 of the third movable baffle 8 serves as the hypotenuse of the right-angled trapezoid. It is understandable that the inclined sides 81 can also be arranged in opposite directions.

[0036] See Figure 6 The third movable baffle 8 can be a right-angled triangular structure, formed by three steel plates. The outer surface of its hypotenuse steel plate serves as an inclined side 81, and the angle between the hypotenuse steel plate and the long right-angle steel plate is 30°. Two third legs equipped with third pulley assemblies 83 are also connected to the outer side of the long right-angle steel plate for friction-reducing movement. This arrangement is because the hypotenuse design can reduce boundary interference, thereby reducing the free gravity response error to <3% and improving the conformity of anisotropic extension deformation.

[0037] It should be further noted that the specific spacing between the plates forming the enclosure area should primarily meet the total extension displacement required for the experiment, i.e., ensure sufficient displacement distance on the moving side. For example, an initial distance of 30cm-40cm can be reserved between the second fixed baffle 7 and the movable plate 23, and between the second enclosure plate 52 and the movable plate 23; other plates can be arranged using this as a reference.

[0038] The present invention also constructs a method for simulating the separation of metamorphic core complexes using the above-mentioned device, the method comprising a free gravity stretching test step, a constant rate stretching test step, and an anisotropic stretching superposition test step; The main steps of the free gravity stretching experiment include: The first set of experimental materials is provided, which includes a substrate material and a brittle material; The first experimental module was constructed by combining the components. The base material is added to the first enclosure area to construct the base layer, and then brittle materials are added to the first enclosure area one by one, so that the first moving baffle 6 slides outward under the gravitational potential energy of the material, and the structural deformation pattern of the material is observed in real time. Multiple sets of observational experiments were conducted to select the experimental group whose tectonic evolution pattern best matched the prototype, thereby obtaining the optimal extension rate characterizing the key stage of tectonic evolution. The main steps of a constant rate tensile test include: A second set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies. Combine and construct the second experimental module; A base material and a brittle material are added to the second enclosure region to construct a base layer and a brittle layer, and a viscous medium is embedded in a predetermined position in the base layer as an experimental variable; The control plate 23 continuously stretches the material at the optimal stretching rate; A control group without embedded viscous medium was set up, and the difference in the dip angle evolution of the detachment fault in the two groups of experiments was recorded to confirm the role of the rheological anomaly. The main steps of the anisotropic stretching superposition experiment include: A third set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies. Combine and construct the third experimental module; A base material and a brittle material are added to the third enclosure region to construct a base layer and a brittle layer, and a viscous medium is embedded in a predetermined position in the base layer; By applying stress in different directions to the material through the outward sliding caused by gravity generated by the third moving baffle 8 and the outward stretching caused by the mechanical force generated by the movable plate 23, the formation mechanism of metamorphic core complex under complex stress background is simulated, and experimental results are obtained.

[0039] Furthermore, in the free gravity stretching experiment, the first experimental module can be constructed as follows: See Figure 1 A pair of transparent tempered glass panels are symmetrically fixed to the support platform 1 at intervals. A movable plate 23 and a first movable baffle 6 are placed between the two glass panels and fitted against the transparent tempered glass panels, thus forming a square structure with an open top. The first movable baffle 6 rests on the platform by pulleys and is in a limited position.

[0040] Then, during the experimental phase, a viscous material of a predetermined viscosity was uniformly laid into the square structure as a base layer. Next, granular material was uniformly laid onto the base layer as a brittle layer.

[0041] Next, the limiting position of the first moving baffle 6 is released. Under the influence of gravity of the brittle and ductile layers, the first moving baffle 6 moves away from the movable plate 23. The moving distance of the first moving baffle 6 is controlled, and after each movement, the same deposited granular material is laid, repeating this process several times.

[0042] The material's structural deformation process was monitored in real time, with a focus on recording the attenuation characteristics of the strain rate over time. Through comparison of multiple experimental sets (including parallel and / or comparative experiments), the experimental group whose structural pattern (including fault geometry and deformation sequence) best matched the prototype of the metamorphic core complex in nature was selected. Based on the elongation-time and velocity-time curves of this experimental set, the optimal elongation rate was obtained and used as the input parameter for subsequent constant-rate tensile tests.

[0043] Understandably, this stage aims to simulate the early or specific stages of metamorphic core complex formation, where the lithosphere weakens under thermal stress and undergoes lateral rheology and extension primarily controlled by gravity. Determining the optimal extension rate is to provide kinetic parameters consistent with natural physical laws for subsequent active stretching experiments.

[0044] In the practical free gravity stretching experiment, the viscous material used was silica gel with a viscosity of 5000 Pa·s, laid to a thickness of 8 cm. The granular material used was quartz sand of 40-70 mesh or 80-120 mesh, with an internal friction angle of 31°. The brittle layer was laid in layers, with a single layer thickness controlled at 10 ± 0.5 mm. Mineral dyes were added between the layers as time markers to track the stratigraphic sequence evolution during deformation.

[0045] The experiment was conducted in four phases, with a total cumulative displacement of 20 cm. The target extension distances for each phase were 3.5 cm, 5.4 cm, 6.7 cm, and 4.4 cm, respectively. The critical condition was that the sand body would not collapse entirely; the baffle was automatically stopped moving once it reached the preset limit distance for each phase. The optimal extension rate was ultimately determined to be 0.1 cm / min.

[0046] In the constant-rate tensile test, the second experimental module can be constructed by removing all experimental modules and materials from support platform 1 except for drive component 2. Then, see... Figure 2 A pair of transparent tempered glass panels are symmetrically fixed at intervals on the support platform 1; the movable plate 23 and the second fixed baffle 7 are placed between the two glass panels and are attached to the transparent tempered glass panels, thus forming a square structure with an open top. At this time, the second fixed baffle 7 is fixedly located on the platform.

[0047] This experimental phase includes two comparative experiments to verify the effects of the rheological anomaly.

[0048] Control group (no abnormalities): A viscous material with a first preset viscosity is uniformly laid as a base layer in a square structure, and a granular material is uniformly laid as a brittle layer on the base layer. Then, the movable plate 23 is driven to stretch a preset length at an optimal stretching rate.

[0049] Experimental group (including rheological anomalies): First, a viscous material with a first preset viscosity is uniformly laid as a base layer in a square structure. Then, a viscous medium with a relatively lower second preset viscosity is embedded at a preset position in the base layer to simulate a magma intrusion or a localized thermal softening zone. Next, granular material is uniformly laid as a brittle layer on the base layer. Finally, the movable plate 23 is driven to stretch a preset length at an optimal stretching rate.

[0050] By comparing the dip angle and morphology of the detachment faults in the two sets of experiments, it was verified that local thinning and the rise of the ductile layer are the key mechanisms for the formation of metamorphic core complexes, and it was specifically confirmed that the presence of rheological anomalies played a lubricating role, which reduced the dip angle of the detachment faults.

[0051] In the practical free gravity stretching experiment, silica gel with a viscosity of 5000 Pa·s was selected as the viscous material for the base layer, with a thickness of 8 cm. Silica gel with a viscosity of 2000 Pa·s was selected as the viscous medium simulating the rheological anomaly. 40-70 mesh or 80-120 mesh quartz sand was selected as the granular material, with an internal friction angle of 31°. The brittle layer was laid in layers, with a single layer thickness controlled at 10 ± 0.5 mm. Mineral dyes were incorporated between the layers as time markers to track the stratigraphic sequence evolution during deformation. Next, the movable plate 23 was configured to stretch to 10 cm at a speed of 0.1 cm / min.

[0052] Finally, by comparing the dip angle and morphology of the detachment fault in the two sets of experiments, it was confirmed that the presence of the rheological anomaly would reduce the dip angle of the detachment fault by about 15°-25°.

[0053] In the anisotropic stretching superposition experiment, the third experimental module can be constructed by removing all experimental modules and materials from the support platform 1 except for the drive component 2. Then, see... Figure 3 Three acrylic sheets are fixedly installed on the support platform 1, with the first and second acrylic sheets vertically connected and the third acrylic sheet parallel to the second acrylic sheet with a gap between them; a movable plate 23 is placed between the first and third acrylic sheets; a third movable baffle 8 is inserted between the third acrylic sheet and the second acrylic sheet, thus forming a right-angled trapezoidal structure with an open top. At this time, the sides of the movable plate 23 and the third movable baffle 8 are in contact with the acrylic sheets, and the short right-angled sides of the movable plate 23 and the third movable baffle 8 partially overlap in space; the third movable baffle 8 rests on the platform with the help of pulleys and is in a limited position.

[0054] Then, in the experimental phase, a viscous material of a first preset viscosity is uniformly laid into the trapezoidal structure as a base layer. Then, etched grooves of a preset shape and number are cut out at preset positions on the base layer (refer to...). Figure 4It also injects a second preset viscosity with a relatively low viscosity to simulate the viscous medium in the weak zone of the basement, providing mechanical induction for subsequent fault development.

[0055] Subsequently, granular material was evenly laid on the base layer as a brittle layer.

[0056] Next, the three phases of operation will be carried out in sequence: Phase 1: Adjust the third movable baffle 8 to the preset position, then release the limit, so that it extends the first preset length in a controlled manner under the action of gravity, and observe the experimental plane phenomenon; Phase 2: The active board 23 stretches to the second preset length at the optimal stretching rate; Phase 3: The movable plate 23 is stretched to the third preset length to simulate the superposition of clockwise rotation of the stress field and non-coaxial deformation, and the experimental results are obtained.

[0057] This anisotropic extensional superposition experiment aims to simulate and reproduce the dynamic rotation process of the stress field in a rift basin, overcoming the technical limitations of traditional devices with a single loading direction. By observing the experimental process and results, the formation process and final morphology of the metamorphic core complex can be determined. The experimental results provide a reliable physical model basis for structural analysis in deepwater oil and gas exploration and have important reference value.

[0058] In the anisotropic stretching superposition experiment, silicone with a viscosity of 5000 Pa·s was selected as the adhesive material for the base layer, and the thickness was 8 cm. Two elongated grooves (9) were formed, and their distribution can be found in the attached diagram. Figure 4 It should be noted that the position of the etched groove 9 is linked to the spatial positioning of the anomaly, providing a highly reliable experimental basis for the selection of target areas in deep-water oil and gas exploration. The viscous medium used to simulate the rheological anomaly is silica gel with a viscosity of 2000 Pa·s. The granular material is quartz sand of 40-70 mesh or 80-120 mesh, with an internal friction angle of 31°. The brittle layer is laid in layers, with a single layer thickness controlled at 10±0.5 mm, and mineral dyes are incorporated between layers as time markers to track the stratigraphic sequence evolution during deformation.

[0059] Secondly, in the first phase: the third movable baffle 8 extends 5cm to the east; Phase 2: The active board 23 is stretched southward by 9cm at a constant rate of 0.1cm / min; Phase 3: Keep the movable board 23 facing south and continue pulling it for 4cm.

[0060] It should be noted that the direction of movement in the experimental design (such as "east" or "south") is to simulate a specific geological stress field and can be adjusted according to research needs.

[0061] In summary, the experimental apparatus and method for simulating the detachment of metamorphic core complexes of the present invention effectively solves the technical defects of traditional sand box simulations, such as neglecting local rheological anomalies, severe boundary interference, and difficulty in simulating anisotropic stress superposition, providing a more precise experimental means for the study of rift basin tectonic evolution.

[0062] This experimental device adopts a modular design, supports rapid switching between three experimental modes, and improves the flexibility and efficiency of scientific research observation.

[0063] This experimental method comprises three sets of experiments: free gravity stretching, constant-rate stretching, and superimposed anisotropic stretching. In the free gravity stretching experiment, the optimal stretching rate was accurately calibrated by controlling the displacement of a low-friction baffle. This design successfully controlled the error in the free gravity response caused by boundary disturbances to within 3%, ensuring the reliability of the initial dynamic parameters of the experiment.

[0064] In constant-rate tensile tests, the viscosity difference of silica gel successfully simulated local rheological anomalies such as magma intrusion. The experimental results accurately characterized the control mechanism of rheological anomalies on detachment faults, effectively compensating for the problem of traditional models neglecting rheological anomaly bodies.

[0065] In the superimposed anisotropic extensional experiment, dynamic stress adjustment along the NE→SN→EW direction was achieved by combining viscous medium constraint, low-friction baffle, and constant mechanical stretching. This experiment successfully reproduced the dynamic rotation of the stress field and the non-coaxial deformation process in the rift basin, overcoming the limitations of traditional devices with a single loading direction. Thanks to the deep elimination of boundary disturbances, the free gravity response error can be reduced to below 3%, and the structural fit of the anisotropic extensional deformation can be improved to 92%. This invention provides highly reliable experimental evidence and analogical criteria for target area selection and structural interpretation in deepwater oil and gas exploration.

[0066] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A simulation experimental device for the dismantling of metamorphic core complexes, characterized in that, Includes a support platform (1) and experimental elements for mounting on the support platform (1); The experimental components include a drive assembly (2), a first enclosure assembly (3), a second enclosure assembly (4) and a third enclosure assembly (5), a first movable baffle (6), a second fixed baffle (7) and a third movable baffle (8); the drive assembly (2) includes a drive element (21) and a movable plate (23) that can move in a straight line under the drive of the drive element (21), the movable plate (23) being used to cooperate in forming an enclosure area; This experimental setup, through the combination and configuration of different experimental components, can be switched to form any of the following three experimental modules: The first experimental module for free gravity extension includes a drive component (2), a first enclosure component (3) and a first movable baffle (6) for constructing a first enclosure area; the first movable baffle (6) is disposed opposite to the movable plate (23) and is configured to move outward under the force of gravity; The second experimental module for constant rate stretching includes a drive assembly (2), a second enclosure assembly (4) and a second fixed baffle (7) for constructing a second enclosure area; a movable plate (23) is disposed opposite to the second fixed baffle (7) and the movable plate (23) is configured to move outward at a preset rate under the drive of the drive member (21); The third experimental module for anti-directional extension superposition includes a driving component (2), a third enclosure component (5), and a third movable baffle (8) for constructing a third enclosure area; wherein the third movable baffle (8) module is configured to move outward under the force of gravity, the movable plate (23) is configured to move outward at a preset rate under the drive of the driving component (21), and the moving direction of the movable plate (23) is perpendicular to the moving direction of the third movable baffle (8).

2. The experimental apparatus for simulating the dismantling of metamorphic core complexes according to claim 1, characterized in that, The support platform (1) is a polished metal base; the bottom of the first movable baffle (6) and the third movable baffle (8) are both equipped with pulley assemblies.

3. The experimental apparatus for simulating the dismantling of metamorphic core complexes according to claim 1, characterized in that, The first enclosure component (3) includes several transparent tempered glass panels, which together with the first movable baffle (6) and the movable plate (23) form a square structure; The second enclosure component (4) includes several transparent tempered glass panels, which together with the second fixed baffle (7) and the movable plate (23) form a square structure; The third enclosure component (5) includes several transparent acrylic plates, which together with the third movable baffle (8) and the movable plate (23) form a right trapezoidal structure; wherein the third movable baffle (8) is provided with an inclined side (81) to form the hypotenuse of the right trapezoidal structure.

4. The metamorphic core complex dismantling simulation experimental device according to claim 1, characterized in that, The third enclosure assembly (5) includes multiple enclosure panels erected on the support platform (1), including a first enclosure panel (51), a second enclosure panel (52) and a third enclosure panel (53). In the third experimental module, the first enclosure (51) and the second enclosure (52) are vertically connected, and the surface of the first enclosure (51) is parallel to the stretching direction of the drive assembly (2) in space; the third enclosure (53) is parallel to the first enclosure (51) and has a gap with the second enclosure (52); the movable plate (23) is located between the third enclosure (53) and the first enclosure (51) and is set parallel to the second enclosure (52); the third movable baffle (8) is a right-angled triangle structure, inserted from the opposite side of the first enclosure (51) between the third enclosure (53) and the second enclosure (52), and the hypotenuse of the third movable baffle (8) is used to form the boundary of the third enclosure area.

5. The metamorphic core complex dismantling simulation experimental apparatus according to claim 4, characterized in that, The angle between the hypotenuse and the long right-angle side of the third movable baffle (8) is 30°-60°.

6. A method for simulating the dismantling of metamorphic core complexes, characterized in that, This experimental method is implemented using the metamorphic core complex dismantling simulation experimental apparatus described in any one of claims 1-5, and the steps include: Free gravity stretching experiment steps: Construct the first enclosure area using the first experimental module, lay experimental materials to form a base layer and a brittle layer, and make the first moving baffle (6) slide outward under the gravitational potential energy of the experimental materials; conduct multiple sets of observation experiments to screen out the best stretching rate; Constant rate stretching test steps: Construct the second enclosure area using the second experimental module, lay experimental materials to form a base layer and a brittle layer, and use whether the base layer contains a viscous medium as a control variable. Then control the movable plate (23) to stretch the experimental materials at the optimal stretching rate. By comparing the changes in the dip angle of the detachment fault in the two sets of experiments, the influence of the rheological anomaly on the formation of the metamorphic core complex can be determined. Anisotropic stretching superposition experiment steps: The third enclosure area is constructed using the third experimental module, experimental materials are laid to form a base layer and a brittle layer, and a viscous medium is embedded in the base layer. Then, the third moving baffle (8) slides outward under gravity and the moving plate (23) is mechanically stretched outward at the optimal stretching rate to simulate the stress field rotation and non-coaxial deformation process, thereby obtaining the experimental results.

7. The method for simulating the dismantling of metamorphic core complexes according to claim 6, characterized in that, The specific steps of the free gravity stretching experiment include: The first set of experimental materials is provided, which includes a substrate material and a brittle material; The first experimental module was constructed by combining the components. A base material is uniformly laid as a base layer in the first enclosure area, and a granular material is laid on top of it as a brittle layer. Release the first movable baffle (6) from its limit, so that it moves away from the movable plate (23) under the action of the material's gravity; Control the moving distance of the first moving baffle (6), and after each period of movement, lay the same deposited granular material, repeating this process several times; Based on the above steps, multiple sets of experiments were compared, and the experimental group whose construction style best matched the preset prototype was selected. The stretching rate of this experimental group was then determined as the optimal stretching rate for subsequent experiments.

8. The method for simulating the dismantling of metamorphic core complexes according to claim 6, characterized in that, The specific steps of a constant rate tensile test include: A second set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies; the viscosity of the viscous medium is lower than that of the substrate material. Combine and construct the second experimental module; A base material and a brittle material are added to the second enclosure region to construct a base layer and a brittle layer, and a viscous medium is embedded in a predetermined position in the base layer as an experimental variable; Control the moving plate (23) to continuously stretch the material at the optimal stretching rate; A control group without embedded viscous medium was set up, and the difference in the dip angle evolution of the detachment fault in the two groups of experiments was recorded to confirm the role of the rheological anomaly.

9. The method for simulating the dismantling of metamorphic core complexes according to claim 6, characterized in that, The specific steps of the anisotropic stretching superposition experiment include: A third set of experimental materials is provided, which includes a substrate material, a brittle material, and a viscous medium for simulating rheological anomalies; the viscosity of the viscous medium is lower than that of the substrate material. Combine and construct the third experimental module; A base layer is laid in the third enclosure area, and an etching groove (9) is set at a preset position in the base layer and a viscous medium is poured in. The stress is applied in three stages: in the first stage, the limit of the third movable baffle (8) is released, so that it is stretched to the first preset length under the action of gravity; in the second stage, the movable plate (23) is controlled to stretch to the second preset length at the optimal stretching rate; in the third stage, the movable plate (23) is maintained to continue to stretch to the third preset length, so as to obtain the experimental results.

10. The method for simulating the dismantling of metamorphic core complexes according to claim 9, characterized in that, The substrate material is silica gel with a viscosity of 5000 Pa·s and a thickness of 8 cm. The etched grooves (9) are arranged in several strips, all of which are long strips and are intermittently embedded on the substrate layer along the moving direction of the third moving baffle (8). The viscous medium is silica gel with a viscosity of 2000 Pa·s. The brittle material is quartz sand of 40-70 mesh or 80-120 mesh. The brittle layer is laid in layers, with the thickness of each layer controlled at 10±0.5mm, and mineral dyes are added between the layers as time markers; In the three-stage stress application, the third moving baffle (8) in the first stage stretches 5cm, the moving plate (23) in the second stage stretches 9cm at a constant rate of 0.1cm / min, and the moving plate (23) in the third stage is held at a constant stretch of 4cm.

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