A method for prospecting lithium-potassium-boron brine deposit in a faulted basin tectonic transition zone

Abstract

The application provides a prospecting method for a brine type lithium-potassium-boron deposit in a fault basin tectonic conversion area, and the method comprises the following steps: determining a target layer type; obtaining gravity and magnetic data and seismic data of the fault basin, identifying faults and / or identifying deep faults and / or identifying volcanic rock bodies, and determining a first favorable ore-forming tectonic unit; for the first favorable ore-forming tectonic unit, analyzing differential subsidence of adjacent tectonic units, and determining a second favorable ore-forming tectonic unit; for the second favorable ore-forming tectonic unit, determining a first favorable exploration area, and further determining a second favorable exploration area; and for the determined second favorable exploration area, drilling verification is carried out, and physical parameters of the brine type lithium-potassium-boron deposit are detected. The application can quickly and accurately delineate the brine type lithium-potassium-boron deposit in the fault basin, and is especially suitable for rapid positioning and evaluation of the brine type lithium-potassium-boron resource in the continental fault basin.

Description

Technical Field

[0001] This application relates to the field of geological exploration technology for lithium, potassium, and boron deposits, specifically to a prospecting method for brine-type lithium, potassium, and boron deposits in tectonic transformation zones of rift basins. Background Technology

[0002] With the rapid development of the global new energy and new materials industries, the demand for strategic mineral resources such as potassium (K), lithium (Li), and boron (B) has increased dramatically. Lithium, as a core raw material for power batteries, has become a key resource for energy transition; potassium salts are an important source of agricultural fertilizers; and boron is widely used in high-temperature alloys, glass, and ceramics. In recent years, brine deposits have become an important source of potassium, lithium, and boron resources due to their large reserves and relatively low mining costs, especially in closed basins in arid and semi-arid regions, where brine deposits are often closely associated with salt lakes or deep underground brine systems.

[0003] As a typical active tectonic unit, rift basins often develop multiple phases and types of tectonic transition zones (such as fault zones, slope zones, and depression-uplift transition zones). These tectonic transition zones, due to variations in tectonic stress fields, complex fluid migration channels, and differentiated sedimentary environments, often become favorable areas for brine enrichment and mineralization. Currently, existing technologies both domestically and internationally focus primarily on the exploration of shallow saline lake brines or single tectonic units, while research on brine-type multi-element symbiotic deposits in deep tectonic transition zones is relatively weak. In particular, a complete prospecting technology system has not yet been established to address the unique "tectonic control of the basin, basin control of brine, and brine control of mineralization" pattern characteristic of rift basins. Therefore, there is an urgent need to develop an efficient prospecting method for brine-type lithium, potassium, and boron deposits in tectonic transition zones of rift basins. This method should integrate and innovate multidisciplinary technologies to overcome the technical bottlenecks in resource exploration under complex geological conditions, providing scientific support for increasing the reserves of strategic mineral resources. Summary of the Invention

[0004] To address the problems existing in the prior art, this application provides a prospecting method for brine-type lithium, potassium, and boron deposits in tectonic transition zones of rift basins, the method comprising:

[0005] By using a global paleoclimate database, we screened drought events that occurred during the formation and evolution of rift basins to identify potential mineral exploration layers.

[0006] For the potential mineral exploration target layer, the type of mineral exploration target layer is determined based on the thickness of the evaporite minerals in the mineral exploration target layer and the proportion of potassium magnesium salt minerals in the evaporite minerals in the mineral exploration target layer;

[0007] Gravity and magnetic data and seismic data of the rift basin are acquired, and the gravity and magnetic data and seismic data are processed and geologically interpreted to obtain interpreted gravity and magnetic data and interpreted seismic data. Based on the interpreted gravity and magnetic data and interpreted seismic data, faults are identified, and first-order favorable metallogenic structural units are determined, and / or deep and large faults are identified, and first-order favorable metallogenic structural units are determined, and / or volcanic rock masses are identified, and first-order favorable metallogenic structural units are determined. The first-order favorable metallogenic structural units include dominant favorable metallogenic structural units, well favorable metallogenic structural units, and generally favorable metallogenic structural units.

[0008] For the first-level favorable metallogenic tectonic unit, analyze the differential subsidence of adjacent tectonic units to determine the second-level favorable metallogenic tectonic unit;

[0009] For the aforementioned secondary favorable metallogenic tectonic units, seismic data, gravity and magnetic data, borehole data and outcrop data are used to determine low-lying areas, and combined with the fault structures and volcanic rock mass distribution range of the rift basin, primary favorable exploration areas are determined.

[0010] For the first-level favorable exploration area, fluvial facies, deltaic facies, and sedimentary microfacies are identified to determine the second-level favorable exploration area;

[0011] For the identified secondary favorable exploration areas, borehole verification was carried out, and the contents of K, Li, and B were analyzed by ICP-MS to detect the physical properties of brine-type lithium-potassium-boron deposits.

[0012] Furthermore, the identification of faults and determination of first-order favorable mineralization tectonic units includes:

[0013] Based on the gravity and magnetic data of the rift basin, the fault type and fault activity intensity of the tectonic transformation zone of the rift basin are determined.

[0014] Based on the seismic data of the rift basin, the fault types and fault activity intensity of the tectonic transformation zone of the rift basin determined by gravity and magnetic data are compared, and the fault types, development characteristics and tectonic activity periods of the target mineral layer and its surrounding layers are analyzed.

[0015] Based on the fault type, development characteristics, and tectonic activity period of the target mineral layer and its surrounding layers, first-order favorable mineral-forming tectonic units are determined.

[0016] Furthermore, the determination of first-order favorable metallogenic tectonic units based on the fault type, development characteristics, and tectonic activity phases of the target mineral layer and its surrounding strata includes:

[0017] Determine the activity intensity of normal faults and detachment faults after the formation of the mineral exploration target layer. If the activity intensity is strong or moderate, the structural unit where the normal fault and detachment fault are located is classified as a dominant and favorable mineralization structural unit.

[0018] Determine the activity intensity of the reverse fault after the formation of the mineral exploration target layer. If the activity intensity is weak, then the structural unit where the reverse fault is located is classified as a dominant and favorable mineralization structural unit.

[0019] Determine the timing of the structural reversal and strike-slip of the strike-slip fault and the inversion fault. If the strike-slip fault and the inversion fault occur after the formation of the target mineral layer, then the structural unit where the strike-slip fault and the inversion fault are located is classified as a dominant and favorable mineral-forming structural unit.

[0020] Furthermore, the identification of faults and determination of favorable mineralized structural units includes:

[0021] For the structural unit where the fault is located, determine the burial depth of the target mineral layer and calculate the normal temperature of the target mineral layer based on the annual average surface temperature.

[0022] Collect geophysical logging data of the tectonic unit where the fault is located to determine the well temperature of the target mineral layer;

[0023] If the well temperature of the target mineral layer is greater than 140% of the normal temperature, the structural unit where the fault is located is classified as a dominant and favorable mineralization structural unit.

[0024] If the well temperature of the target mineral layer is greater than 120% of the normal temperature but less than or equal to 140% of the normal temperature, then the structural unit where the fault is located is classified as a favorable mineralization structural unit.

[0025] If the well temperature of the target mineral layer is less than or equal to 120% of the normal temperature, then the structural unit where the fault is located is classified as a generally favorable mineralization structural unit.

[0026] Furthermore, the identification of deep faults and determination of first-order favorable metallogenic tectonic units includes:

[0027] By combining the analysis of Bouguer gravity anomaly gradient bands and aeromagnetic vertical second derivative anomalies, the spatial distribution and activity of deep and large faults are identified.

[0028] The geometric morphology of the fault is further refined by using the coherence volume and curvature properties of seismic data. The intensity of activity is quantitatively characterized by the abrupt change in the dip angle of the fault and the thickness ratio of the growing strata. The development characteristics of deep and large faults after the formation of the target mineral layer are analyzed.

[0029] If, after the formation of the target mineral layer, the deep fault manifests as a normal fault or a detachment fault, then the structural unit in which the deep fault is located is classified as a dominant and favorable mineral-forming structural unit.

[0030] If, after the formation of the target mineral layer, the deep fault manifests as a strike-slip fault or a reverse fault, then the structural unit where the deep fault is located is classified as a favorable mineralization structural unit.

[0031] Furthermore, the identification of volcanic rock masses and determination of first-order favorable mineralization tectonic units includes:

[0032] By combining gravity and magnetic anomaly analysis and vertical guide processing to enhance boundary identification, determine the spatial morphology of rock masses, and identify volcanic rocks, sedimentary rocks, or intrusive rocks;

[0033] If a tectonic unit contains volcanic rock masses and the distribution range is greater than or equal to 1 / 5 of the area of ​​the tectonic unit, then the tectonic unit is classified as a dominant and favorable metallogenic tectonic unit.

[0034] If a tectonic unit contains volcanic rock masses, and the distribution range is greater than or equal to 1 / 10 and less than 1 / 5 of the area of ​​the tectonic unit, then the tectonic unit is classified as a favorable mineralization tectonic unit.

[0035] If a tectonic unit contains volcanic rock masses and the distribution range is less than 1 / 10 of the area of ​​the tectonic unit, then the tectonic unit is classified as a generally favorable mineralization tectonic unit.

[0036] Furthermore, for the first-order favorable metallogenic tectonic unit, analyzing the differential subsidence of adjacent tectonic units to determine the second-order favorable metallogenic tectonic units includes:

[0037] For a dominant and favorable metallogenic tectonic unit, if there is a subsidence difference between adjacent tectonic units in the stratum below the target mineralization layer, and this relative subsidence difference continues after it is formed, then the footwall is classified as a type A dominant and favorable metallogenic tectonic unit.

[0038] For a dominant and favorable metallogenic tectonic unit, if there is no difference in subsidence in the stratum below the target mineralization layer of an adjacent tectonic unit, but there is a difference in subsidence when the target mineralization layer was formed, and this relative difference in subsidence continues thereafter, then the footwall is classified as a type B dominant and favorable metallogenic tectonic unit.

[0039] For a favorable metallogenic structural unit, if there is a subsidence difference between adjacent structural units in the stratum below the target mineralization layer, but this differential subsidence ends after the target mineralization layer is formed, the footwall is classified as a Class A favorable metallogenic structural unit.

[0040] For a favorable metallogenic tectonic unit, if there is no subsidence difference in the stratum below the target mineralization layer in an adjacent tectonic unit, but there is a subsidence difference when the target mineralization layer is formed, and this subsidence difference ends after the target mineralization layer is formed, then the footwall is classified as a type B favorable metallogenic tectonic unit.

[0041] For a generally favorable metallogenic structural unit, if there is no difference in subsidence between the stratum below the target mineralization layer and the target mineralization layer, but there is differential subsidence after the target mineralization layer is formed, and this relative subsidence difference continues thereafter, then the footwall is classified as a Class A generally favorable metallogenic structural unit.

[0042] For a typical favorable metallogenic structural unit, if there is no difference in subsidence between the stratum below the target mineralization layer and the target mineralization layer, but there is differential subsidence after the target mineralization layer is formed, and the differential subsidence ends thereafter, then the footwall is determined to be a type B typical favorable metallogenic structural unit.

[0043] Furthermore, for the aforementioned secondary favorable metallogenic tectonic units, seismic data, gravity and magnetic data, borehole data, and outcrop data are used to determine low-lying areas. Combined with the fault structures and volcanic rock mass distribution range of the rift basin, primary favorable exploration areas are determined, including:

[0044] By interpreting seismic reflection profiles, faults, basement interfaces, and sedimentary layer thicknesses were identified, and the basement depression area was preliminarily delineated.

[0045] Process gravity and magnetic data, extract low gravity anomalies and areas of gentle magnetic fields, and verify them by comparing them with the depth of the seismic basement.

[0046] Using seismic interpretation results to constrain joint gravity and magnetic inversion, and fitting measured data to accurately characterize the spatial morphology of low-lying areas;

[0047] By combining borehole data and outcrop data for calibration, the low-lying areas were comprehensively determined.

[0048] Compare the spatial relationships between low-lying areas and normal faults and volcanic rock masses within the same favorable metallogenic tectonic unit;

[0049] If the low-lying area is located around a normal fault and a volcanic rock mass, then the low-lying area is determined to be a favorable exploration area.

[0050] If the low-lying area is located around a normal fault or volcanic rock mass, then the low-lying area is considered a good and favorable exploration area.

[0051] If a low-lying area is within 50 km of a normal fault or volcanic rock mass, then the low-lying area is considered a generally favorable exploration area.

[0052] Furthermore, the identification of fluvial and deltaic facies and sedimentary microfacies in the primary favorable exploration area to determine the secondary favorable exploration area includes:

[0053] Well-seismic calibration is used to match sand bodies interpreted from well logging with seismic facies, and combined with seismic attributes and regional sedimentary background, fluvial and deltaic facies are identified.

[0054] Identify deltaic sedimentary microfacies based on the identification markers of deltaic sedimentary microfacies;

[0055] Identify fluvial sedimentary microfacies based on fluvial sedimentary microfacies identification markers;

[0056] Based on grain size, single sand body thickness, and sand-to-land ratio, the order of superiority of brine reservoir sand bodies in deltaic sedimentary systems and fluvial sedimentary systems was determined. The order of superiority of brine reservoir sand bodies in deltaic sedimentary systems is as follows: distributary channel microfacies, mouth bar microfacies, underwater distributary channel microfacies, crevasse fan microfacies, and sheet sand microfacies. The order of superiority of brine reservoir sand bodies in fluvial sedimentary systems is as follows: channel infill, mid-channel bar, side bar, abandoned channel, and natural levee.

[0057] Based on the order of superiority of brine reservoir sand bodies in the deltaic sedimentary system and the order of superiority of brine reservoir sand bodies in the fluvial sedimentary system, a secondary favorable exploration area was determined.

[0058] Furthermore, the ranking of brine reservoir sand bodies in the deltaic sedimentary system and the fluvial sedimentary system determines secondary favorable exploration areas, including:

[0059] For deltaic sedimentary systems, the method for determining secondary favorable exploration areas is as follows:

[0060] If a dominant and favorable exploration area develops distributary channel microfacies, then the dominant and favorable exploration area is classified as a Class A dominant and favorable exploration area.

[0061] If the advantageous exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the advantageous exploration area will be classified as a Class B advantageous exploration area.

[0062] If the advantageous exploration area develops crevice fan microfacies and sheet sand microfacies, then the advantageous exploration area is classified as a Class C advantageous exploration area.

[0063] If a favorable exploration area develops distributary channel microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0064] If the favorable exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the favorable exploration area will be classified as a Class B favorable exploration area.

[0065] If the favorable exploration area develops crevice fan microfacies and sheet sand microfacies, then the favorable exploration area will be classified as a Class C favorable exploration area.

[0066] If a generally favorable exploration area develops distributary channel microfacies, then the generally favorable exploration area is classified as a Class A generally favorable exploration area.

[0067] If a generally favorable exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the generally favorable exploration area is classified as a Class B generally favorable exploration area.

[0068] If a generally favorable exploration area develops crevice fan microfacies or sheet sand microfacies, then the generally favorable exploration area is classified as a Class C generally favorable exploration area.

[0069] For fluvial sedimentary systems, the method for determining secondary favorable exploration areas is as follows:

[0070] If a favorable exploration area develops a channel-filling microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0071] If a favorable exploration area develops a center bar and a side bar, then the favorable exploration area is classified as a Class B favorable exploration area.

[0072] If the advantageous exploration area has developed abandoned river channels or natural levees, then the advantageous exploration area will be classified as a Class C advantageous exploration area.

[0073] If a favorable exploration area develops channel-filling microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0074] If a favorable exploration area develops a core bar and a side bar, then the favorable exploration area is classified as a Class B favorable exploration area.

[0075] If abandoned river channels or natural levees are developed in a favorable exploration area, then the favorable exploration area will be classified as a Class C favorable exploration area.

[0076] If a generally favorable exploration area develops channel-filling microfacies, then the generally favorable exploration area is classified as a Class A generally favorable exploration area.

[0077] If a generally favorable exploration area develops a center bar and a side bar, then the generally favorable exploration area is classified as a Class B generally favorable exploration area.

[0078] If a generally favorable exploration area has abandoned river channels or natural levees, then the generally favorable exploration area is classified as a Class C generally favorable exploration area.

[0079] Based on the above-mentioned invention, compared with the prior art, this application, starting from the actual needs and metallogenic characteristics of brine-type lithium, potassium, and boron deposits, focuses on the key area of ​​tectonic transformation zones in rift basins and innovatively proposes a multi-element coupled tectonic ore-controlling model. It combines a global paleoclimate database to accurately screen drought events, achieving rapid identification of target layers for lithium, potassium, and boron-rich brine exploration through paleoclimate-tectonic synergy; through the fusion of gravity, magnetic, and seismic data, it integrates key elements such as faults, fractures, volcanic rocks, and differential subsidence to dynamically optimize favorable metallogenic tectonic units; based on seismic data, it characterizes tectonic depressions and sedimentary facies to determine favorable exploration areas. Finally, through borehole verification and efficient ICP-MS detection technology, it determines whether lithium, potassium, and boron meet industrial utilization requirements. This forms an integrated evaluation system of "determination of target layers for exploration - optimization of favorable metallogenic tectonic units - optimization of favorable exploration areas - borehole + geochemical verification," significantly improving the exploration efficiency of brine-type lithium, potassium, and boron resources in continental rift basins. Attached Figure Description

[0080] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0081] Figure 1 This is a schematic flowchart of a prospecting method for brine-type lithium, potassium, and boron deposits in a tectonic transformation zone of a rift basin, provided in an embodiment of this application. Detailed Implementation

[0082] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0083] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0084] See Figure 1 This is a schematic flowchart illustrating a prospecting method for brine-type lithium-potassium-boron deposits in a tectonic transition zone of a rift basin, provided by an embodiment of the present invention. Figure 1 As shown, the method specifically includes:

[0085] Step S1: Using the global paleoclimate database, screen for drought events experienced during the formation and evolution of rift basins to identify potential mineral exploration layers.

[0086] Collect global paleoclimate databases (such as Pangaea and NOAAPaleoclimatology), screen for drought events experienced during the formation and evolution of rift basins, and identify sedimentary strata formed during drought events and their adjacent strata as potential mineral exploration targets.

[0087] Step S2: For the potential mineral exploration target layer, determine the type of mineral exploration target layer based on the thickness of the evaporite minerals in the mineral exploration target layer and the proportion of potassium magnesium salt minerals in the evaporite minerals in the mineral exploration target layer.

[0088] In the mineralization process of salt lake brine, evaporite minerals include sulfate minerals, borate minerals, halite minerals, and potassium-magnesium salt minerals. The formation sequence of evaporite minerals is mainly controlled by the degree of evaporation concentration and mineral solubility. According to typical evaporite sedimentary sequences, the order of formation of evaporite minerals is usually: sulfate minerals, borate minerals, halite minerals, and potassium-magnesium salt minerals.

[0089] Drilling data from the rift basin were collected, focusing on potential mineral exploration layers to determine if the aforementioned evaporite minerals were present. If evaporite minerals were present, the type of exploration layer was determined based on their thickness. If the evaporite mineral thickness was greater than or equal to 1 / 4 of the layer's thickness, the potential exploration layer was classified as a high-quality exploration layer; if the evaporite mineral thickness was greater than or equal to 1 / 8 but less than 1 / 4 of the layer's thickness, it was classified as a good exploration layer; and if the evaporite mineral thickness was less than 1 / 8 of the layer's thickness, it was classified as a general exploration layer.

[0090] Based on the proportion of potassium and magnesium salt minerals in the evaporite minerals of the target mineral layer, the type of the target mineral layer can be further determined.

[0091] If the proportion of potassium-magnesium salt minerals in the evaporite minerals of a high-quality prospecting layer is greater than or equal to 1 / 6, then the high-quality prospecting layer is designated as a Class A high-quality prospecting layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a high-quality prospecting layer is greater than or equal to 1 / 10 and less than 1 / 6, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the high-quality prospecting layer is designated as a Class B high-quality prospecting layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a high-quality prospecting layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the high-quality prospecting layer is designated as a Class C high-quality prospecting layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a high-quality prospecting layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is less than 1 / 6, then the high-quality prospecting layer is designated as a Class D high-quality prospecting layer.

[0092] If the proportion of potassium-magnesium salt minerals in the evaporite minerals of a good prospecting target layer is greater than or equal to 1 / 6, then the good prospecting target layer is designated as a Class A good prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a good prospecting target layer is greater than or equal to 1 / 10 and less than 1 / 6, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the good prospecting target layer is designated as a Class B good prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a good prospecting target layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the good prospecting target layer is designated as a Class C good prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a good prospecting target layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is less than 1 / 6, then the good prospecting target layer is designated as a Class D good prospecting target layer.

[0093] If the proportion of potassium-magnesium salt minerals in the evaporite minerals of a general prospecting target layer is greater than or equal to 1 / 6, then the general prospecting target layer is designated as a Class A general prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a general prospecting target layer is greater than or equal to 1 / 10 and less than 1 / 6, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the general prospecting target layer is designated as a Class B general prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a general prospecting target layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is greater than or equal to 1 / 6, then the general prospecting target layer is designated as a Class C general prospecting target layer; if the proportion of potassium-magnesium salt minerals in the evaporite minerals of a general prospecting target layer is less than 1 / 10, and the proportion of borate minerals and halite minerals is less than 1 / 6, then the general prospecting target layer is designated as a Class D general prospecting target layer.

[0094] Mineral exploration analysis is conducted in the areas where mineral exploration target layers are located, following the order of high-quality mineral exploration target layers, good mineral exploration target layers, and general mineral exploration target layers.

[0095] Step S3: Obtain gravity and magnetic data and seismic data of the rift basin, process and geologically interpret the gravity and magnetic data and seismic data to obtain interpreted gravity and magnetic data and interpreted seismic data;

[0096] Based on the interpreted gravity and magnetic data and the interpreted seismic data, faults are identified to determine first-order favorable metallogenic tectonic units and / or deep and large faults are identified to determine first-order favorable metallogenic tectonic units and / or volcanic rock masses are identified to determine first-order favorable metallogenic tectonic units; the first-order favorable metallogenic tectonic units include dominant favorable metallogenic tectonic units, good favorable metallogenic tectonic units and generally favorable metallogenic tectonic units.

[0097] Processing of gravity and magnetic data includes:

[0098] (1) Bouguer gravity anomaly data processing workflow:

[0099] a. Convert publicly available XYZ gravity data into mesh files; b. Calculate free-air anomalies; c. Perform Bouguer correction; d. Perform terrain correction; e. Verify accuracy. The density in the rift basin was selected as 2.3-2.5 g / cm³. 3 During terrain correction, the data area should be extended by at least 50 km to avoid boundary errors; the error should be checked by comparing with known absolute gravity points (such as BGI benchmarks) to ensure that the error is <1 mGal.

[0100] Spatial derivatives are calculated using horizontal gradient (THG) and vertical gradient (VG) algorithms, and significant gradient bands are extracted using threshold segmentation or edge enhancement techniques to obtain Bouguer gravity anomaly maps.

[0101] (2) Processing flow for the vertical second derivative of aeromagnetic motion:

[0102] a. Data preprocessing stage: Specifically, Kriging interpolation is used to grid the data, with the grid spacing set to 1 / 3 of the flight altitude; b. Frequency domain transformation calculation: This includes performing a fast Fourier transform on the grid data; c. Calculation result optimization: Regularized inversion is used to suppress noise amplification; upward extension verification is performed, with the extension height ≥ 3 times the grid spacing; and moving average filtering is used to smooth high-frequency oscillations.

[0103] The identification of faults, determining first-order favorable mineralized tectonic units, includes:

[0104] First, based on the gravity and magnetic data of the rift basin, the fault type and fault activity intensity of the tectonic transformation zone of the rift basin are determined.

[0105] Graben basins typically contain normal faults, detachment faults, inversion faults, strike-slip faults, and reverse faults. Fault types are determined based on their response to gravity and magnetic data profiles, specifically including:

[0106] If the Bouguer gravity anomaly gradient zone corresponding to the fault has a linear high value, the zero line of the magnetic vertical guide coincides with the gravity gradient axis, and the magnetic anomaly vertical guide shows a steep change on one side of the same dip, then the fault is determined to be a normal fault.

[0107] If the gravity gradient zone corresponding to the fault is arc-shaped, the magnetic vertical guide number shows a "double zero line", and the magnetic permeability value drops sharply in the hanging wall of the fault, then the fault is determined to be a detachment fault.

[0108] If the Bouguer gravity anomaly corresponding to the fault is a linear gradient zone, and the magnetic anomaly is a high-intensity linear stripe or fault, then the fault is determined to be a strike-slip fault.

[0109] If the Bouguer gravity anomaly corresponding to the fault is low in the early stage and high in the later stage, and the magnetic anomaly basement is uplifted, leading to complexity, then the fault is determined to be an inversion fault.

[0110] If the Bouguer gravity anomaly corresponding to the fault shows a higher value in the hanging wall and a lower value in the footwall, and the magnetic anomaly shows a higher magnetic force in the hanging wall and a quiet magnetic field in the front edge, then the fault is determined to be a reverse fault;

[0111] The extensional characteristics of the normal fault, detachment fault, strike-slip fault, inversion fault, and reverse fault decrease in order. The stronger the extensional characteristics of the fault, the more favorable it is for the formation of brine-type lithium, potassium, and boron deposits.

[0112] After interpreting the fault type based on the gravity and magnetic data profiles, calculate the gravity gradient slope Kg or calculate the magnetic activity index MAI, and judge the fault activity intensity according to the gravity gradient slope Kg or the magnetic activity index MAI;

[0113] The judgment of the fault activity intensity according to the gravity gradient slope Kg includes:

[0114] If Kg > 20, it is determined that the fault activity is strong;

[0115] If 10 < Kg ≤ 20, it is determined that the fault activity is medium;

[0116] If Kg ≤ 10, it is determined that the fault activity is weak;

[0117] The judgment of the fault activity intensity according to the magnetic activity index MAI includes:

[0118] If MAI > 80 nT / m 2 / km, it is determined that the fault activity is strong;

[0119] If 30 nT / m 2 / km < MAI ≤ 80 nT / m 2 / km, it is determined that the fault activity is medium;

[0120] If MAI ≤ 30 nT / m 2 / km, it is determined that the fault activity is weak.

[0121] Secondly, based on the seismic data of the fault basin, compare the fault type and fault activity intensity of the fault basin tectonic transition zone determined according to the gravity and magnetic data, and analyze the fault type, development characteristics, and tectonic activity periods of the ore-bearing target layer and its surrounding horizons.

[0122] Constrained by borehole data, trace each reflection interface of the seismic profile to determine the strata, especially the spatial distribution of the ore-bearing target layer.

[0123] Seismic attributes such as coherence, curvature, and spectral decomposition are used to identify syn-sedimentary faults, growth strata, and overlap / underlap interfaces, thus classifying tectonic activity periods (e.g., rifting and depression periods). The focus is on analyzing the fault attributes, development characteristics, and activity periods of the target mineral layer and its surrounding strata, identifying faults that were active after the formation of the target mineral layer, early-stage active faults, and later-stage reactivation faults. These findings are then compared with faults interpreted from gravity and magnetic data profiles to further determine the developmental characteristics of faults within the target mineral layer.

[0124] Finally, based on the fault types, development characteristics, and tectonic activity periods of the target mineral layer and its surrounding layers, first-order favorable metallogenic tectonic units are determined.

[0125] Determine the activity intensity of normal faults and detachment faults after the formation of the mineral exploration target layer. If the activity intensity is strong or moderate, the structural unit where the normal fault and detachment fault are located is classified as a dominant and favorable mineralization structural unit.

[0126] Determine the activity intensity of the reverse fault after the formation of the mineral exploration target layer. If the activity intensity is weak, then the structural unit where the reverse fault is located is classified as a dominant and favorable mineralization structural unit.

[0127] Determine the timing of the structural reversal and strike-slip of the strike-slip fault and the inversion fault. If the strike-slip fault and the inversion fault occur after the formation of the target mineral layer, then the structural unit where the strike-slip fault and the inversion fault are located is classified as a dominant and favorable mineral-forming structural unit.

[0128] In one embodiment, identifying faults to determine first-order favorable mineralized structural units may include:

[0129] For the structural unit where the fault is located, determine the burial depth of the target mineral layer and calculate the normal temperature of the target mineral layer based on the annual average surface temperature.

[0130] The geothermal gradient in rift basins is generally 30-35℃ / km, and the geothermal gradient value in this application is 33℃ / km.

[0131] The formula for calculating the normal temperature of the target mineral layer is:

[0132] T z =z*G+T0

[0133] Among them, T z T0 is the temperature at depth z; T0 is the annual average surface temperature; z is the depth; G is the geothermal gradient of the rift basin.

[0134] The normal temperature of the target mineral layer can be calculated using the above formula.

[0135] Collect geophysical logging data from the tectonic unit where the fault is located, analyze the well temperature data, and determine the well temperature of the target mineral layer.

[0136] If the well temperature of the target mineral layer is greater than 140% of the normal temperature, the structural unit where the fault is located is classified as a dominant and favorable mineralization structural unit.

[0137] If the well temperature of the target mineral layer is greater than 120% of the normal temperature but less than or equal to 140% of the normal temperature, then the structural unit where the fault is located is classified as a favorable mineralization structural unit.

[0138] If the well temperature of the target mineral layer is less than or equal to 120% of the normal temperature, then the structural unit where the fault is located is classified as a generally favorable mineralization structural unit.

[0139] In one embodiment, identifying first-order favorable metallogenic tectonic units by recognizing deep and large faults specifically includes:

[0140] By combining Bouguer gravity anomaly gradient zones with aeromagnetic vertical second derivative anomalies, the spatial distribution and activity of deep, large-scale faults are identified. Linear anomaly zones in the horizontal gravity gradient reflect density abrupt change interfaces, while the zero-value line of the vertical derivative of the magnetic anomaly indicates the location of magnetic basement fracturing. The spatial coupling zone between these two zones corresponds to the location of deep, large-scale faults. The presence of deep, large-scale faults facilitates the transport of deep magma / thermal fluids to shallower areas, which is beneficial for uranium mineralization; conversely, the absence of such faults is detrimental.

[0141] By further refining the geometry of faults through the coherence and curvature properties of seismic data, and quantitatively characterizing the intensity of activity based on abrupt changes in fault dip angle and the thickness ratio of growing strata, the development characteristics of deep and large faults after the formation of the target mineral exploration layer are analyzed.

[0142] If, after the formation of the target mineral layer, the deep fault manifests as a normal fault or a detachment fault, then the structural unit in which the deep fault is located is classified as a dominant and favorable mineral-forming structural unit.

[0143] If, after the formation of the target mineral layer, the deep fault manifests as a strike-slip fault or a reverse fault, then the structural unit where the deep fault is located is classified as a favorable mineralization structural unit.

[0144] In one embodiment, identifying favorable primary mineralization tectonic units by recognizing volcanic rock masses specifically includes:

[0145] By combining gravity and magnetic anomaly analysis and vertical guide processing to enhance boundary identification, the spatial morphology of rock masses can be determined, and volcanic rocks can be distinguished from sedimentary or intrusive rocks.

[0146] Identifying volcanic rock masses using gravity and magnetic data primarily relies on differences in density and magnetic properties compared to the surrounding rocks: basic volcanic rocks (such as basalt) have a higher density (2.8–3.0 g / cm³). 3Furthermore, they are rich in magnetic minerals, typically exhibiting localized high gravity and abrupt magnetic anomalies. These anomalies often appear as isolated masses or bands with steep boundary gradients. Intermediate-acidic volcanic rocks (such as rhyolite) have lower density and weaker magnetism, resulting in less pronounced gravity anomalies and smaller magnetic anomaly amplitudes. By combining gravity and magnetic anomaly analysis (e.g., high gravity and high magnetic indices indicating basic rock masses) and using vertical guide processing to enhance boundary identification, the spatial morphology of the rock mass can be determined, effectively distinguishing volcanic rocks from sedimentary or intrusive rocks.

[0147] If a tectonic unit contains volcanic rock masses and the distribution range is greater than or equal to 1 / 5 of the area of ​​the tectonic unit, then the tectonic unit is classified as a dominant and favorable metallogenic tectonic unit.

[0148] If a tectonic unit contains volcanic rock masses, and the distribution range is greater than or equal to 1 / 10 and less than 1 / 5 of the area of ​​the tectonic unit, then the tectonic unit is classified as a favorable mineralization tectonic unit.

[0149] If a tectonic unit contains volcanic rock masses and the distribution range is less than 1 / 10 of the area of ​​the tectonic unit, then the tectonic unit is classified as a generally favorable mineralization tectonic unit.

[0150] Step S4: For the first-level favorable mineralization tectonic unit, analyze the differential subsidence of adjacent tectonic units to determine the second-level favorable mineralization tectonic units.

[0151] Structural subsidence is calculated for the strata below and overlying the target mineral layer using seismic data. The structural unit with relatively higher elevation in adjacent structural units is the hanging wall, and the structural unit with relatively lower elevation is the footwall. The dip angle of the strata is measured using the dip angle of the reflection axis of the target mineral layer from the seismic data. The layer velocity of the target mineral layer can be obtained by collecting seismic geological data, and the differential subsidence is calculated using the following formula. The greater the differential subsidence, the more favorable it is for mineralization.

[0152]

[0153] Among them, v 层 θ is the formation velocity of the target mineral layer; θ is the dip angle of the target mineral layer; t 下盘 For the two-way travel time of the earthquake in the lower plate, t 上盘 This is the two-way travel time for the earthquake on the upper plate.

[0154] For a dominant and favorable metallogenic tectonic unit, if there is a subsidence difference between adjacent tectonic units in the stratum below the target mineralization layer, and this relative subsidence difference continues after it is formed, then the footwall is classified as a type A dominant and favorable metallogenic tectonic unit.

[0155] For a dominant and favorable metallogenic tectonic unit, if there is no difference in subsidence in the stratum below the target mineralization layer of an adjacent tectonic unit, but there is a difference in subsidence when the target mineralization layer was formed, and this relative difference in subsidence continues thereafter, then the footwall is classified as a type B dominant and favorable metallogenic tectonic unit.

[0156] For a favorable metallogenic structural unit, if there is a subsidence difference between adjacent structural units in the stratum below the target mineralization layer, but this differential subsidence ends after the target mineralization layer is formed, the footwall is classified as a Class A favorable metallogenic structural unit.

[0157] For a favorable metallogenic tectonic unit, if there is no subsidence difference in the stratum below the target mineralization layer in an adjacent tectonic unit, but there is a subsidence difference when the target mineralization layer is formed, and this subsidence difference ends after the target mineralization layer is formed, then the footwall is classified as a type B favorable metallogenic tectonic unit.

[0158] For a generally favorable metallogenic structural unit, if there is no difference in subsidence between the stratum below the target mineralization layer and the target mineralization layer, but there is differential subsidence after the target mineralization layer is formed, and this relative subsidence difference continues thereafter, then the footwall is classified as a Class A generally favorable metallogenic structural unit.

[0159] For a typical favorable metallogenic structural unit, if there is no difference in subsidence between the stratum below the target mineralization layer and the target mineralization layer, but there is differential subsidence after the target mineralization layer is formed, and the differential subsidence ends thereafter, then the footwall is determined to be a type B typical favorable metallogenic structural unit.

[0160] Step S5: For the secondary favorable mineralization tectonic units, use seismic data, gravity and magnetic data, borehole data and outcrop data to determine the low-lying areas, and combine the fault structures of the rift basin and the distribution range of volcanic rock masses to determine the primary favorable exploration areas.

[0161] The first-level favorable exploration area includes the dominant favorable exploration area, the good favorable exploration area, and the generally favorable exploration area.

[0162] By collaboratively using seismic and gravity / magnetic data, low-lying areas within the rift basin were identified. Through multi-data fusion and cross-validation, the basin's tectonic framework, basement morphology, and sedimentary infill characteristics were revealed. The specific steps are as follows:

[0163] By interpreting seismic reflection profiles, faults, basement interfaces, and sedimentary layer thicknesses were identified, and the basement depression area was preliminarily delineated.

[0164] Process gravity and magnetic data, extract low gravity anomalies and areas of gentle magnetic fields, and verify them by comparing them with the depth of the seismic basement.

[0165] Using seismic interpretation results to constrain joint gravity and magnetic inversion, and fitting measured data to accurately characterize the spatial morphology of low-lying areas;

[0166] By combining borehole data and outcrop data for calibration, low-lying areas were comprehensively identified.

[0167] Compare the spatial relationships between low-lying areas and normal faults and volcanic rock masses within the same favorable metallogenic tectonic unit;

[0168] If the low-lying area is located around a normal fault and a volcanic rock mass, then the low-lying area is determined to be a favorable exploration area.

[0169] If the low-lying area is located around a normal fault or volcanic rock mass, then the low-lying area is considered a good and favorable exploration area.

[0170] If a low-lying area is within 50 km of a normal fault or volcanic rock mass, then the low-lying area is considered a generally favorable exploration area.

[0171] Step S6: For the first-level favorable exploration area, identify fluvial facies, deltaic facies, and sedimentary microfacies to determine the second-level favorable exploration area.

[0172] Graben basins are mostly terrestrial basins, typically exhibiting various sedimentary types such as fluvial, deltaic, lacustrine, swamp, and fan deltaic facies. Among these, fluvial and deltaic facies deposits often contain well-connected sand bodies, providing transport channels and storage space for brine accumulation. Therefore, identifying fluvial and deltaic facies deposits within favorable metallogenic tectonic units is a key focus in selecting promising exploration areas.

[0173] The identification of sedimentary facies and sedimentary microfacies mainly utilizes seismic and well logging data. By integrating well logging curve morphology analysis with seismic multi-attribute interpretation (coherence, curvature, spectral decomposition), these microfacies can be effectively identified. Well logging data provides precise calibration of vertical lithological variations, while seismic data enables macroscopic characterization of the planar distribution of microfacies. The combination of the two can overcome the limitations of single data.

[0174] Fluvial facies exhibit lenticular or infilling reflections in seismic logging, with a zonal distribution in plan view. Well logging curves show bell-shaped or box-shaped gamma curves, reflecting the positive rhythmic characteristics of channel sand bodies. Deltaic facies, on the other hand, have obvious progradational reflection structures (such as S-shaped or oblique types), with a foliate distribution in plan view. Well logging curves are typically characterized by funnel-shaped gamma curves, indicating anti-rhythmic estuarine bar deposits. By matching the sand bodies interpreted from well logging with seismic facies through well-seismic calibration, and combining seismic attributes (such as coherence volume and root-mean-square amplitude) with the regional sedimentary background, these two sedimentary facies can be effectively distinguished.

[0175] After identifying fluvial and deltaic facies, deltaic sedimentary microfacies are identified based on the identification markers of deltaic sedimentary microfacies; fluvial sedimentary microfacies are identified based on the identification markers of fluvial sedimentary microfacies.

[0176] The deltaic facies sedimentary microfacies identification markers include:

[0177] Distributary channel microfacies: In seismic events, they are characterized by narrow strip-shaped strong amplitude reflections, with lenticular cross-sections and dendritic branching features in planar coherence slices. Well logging curves typically show box-shaped or bell-shaped GR curves, reflecting positive rhythmic sand body deposition. Their formation is controlled by topographic slope and sediment supply, and they often coexist with natural dikes. Trough-shaped cross-bedding can be seen in the core.

[0178] Estuarine bar microfacies: It has a typical progradational reflection structure (S-shaped or oblique type). The funnel-shaped GR curve of well logging reveals anti-rhythmic characteristics. It is formed in the unloading zone of the river entering the lake / sea. It is significantly modified by waves. Wave impedance inversion can effectively identify its sandstone and mudstone interbedded structure.

[0179] Subaqueous distributary channel microfacies: characterized by low-angle downcutting seismic reflection patterns, with amplitudes weaker than those of terrestrial channels. Well logging shows weak box-shaped GR curves and reduced resistivity values. It develops in the delta front subfacies and is often accompanied by slump deformation structures.

[0180] Breach fan microfacies: They appear as small wedge-shaped reflections on seismic data, and planar coherence slices show a fan-shaped distribution. Well logging toothed bell-shaped GR curves reflect rapidly deposited interlayered sand and mud, formed during river breach events during flood season.

[0181] Sheet-like sand microfacies: characterized by thin-layered continuous parallel reflections, which can identify its thin interbedded structure; low-amplitude toothed GR curves in well logging indicate low-energy environment deposition, commonly found in the far end of the delta front.

[0182] The identification markers of deltaic sedimentary microfacies are shown in Table 1.

[0183] Table 1:

[0184] sedimentary microfacies Earthquake reflection characteristics Well logging curve morphology Diversion channel Incision valley filling, box-shaped / mound-shaped reflection Box-shaped or bell-shaped GR, resistivity suddenly increases River Estuary Dam Anterior reflection structure, S-shaped / oblique type Funnel-shaped GR, negative spontaneous potential anomaly Underwater diversion channel Weak amplitude discontinuous reflection, local pre-product Serrated GR, medium to low resistivity The gap fan Cluttered / lens-like reflections, low continuity Low-amplitude tooth profile GR, resistivity fluctuation Sheet sand Parallel-subparallel reflection, high continuity Flat GR baseline, low-resistivity thin film

[0185] The fluvial sedimentary microfacies identification markers include:

[0186] Channel filling microfacies: In well logging, it appears as a box-shaped or bell-shaped GR curve (positive rhythm) with abrupt changes at the bottom, and the resistivity curve shows high values. It corresponds to lenticular strong amplitude reflections on seismic profiles, and the planar coherence properties show a curved strip distribution.

[0187] Heart-shoal microfacies: The logging response is a homogeneous box-shaped GR curve with stable high resistivity, and the seismic amplitude envelope shows irregular patchy high-value areas.

[0188] Sidebar microfacies: It has a typical bell-shaped GR logging curve (positive rhythm) and shows asymmetric lenticular reflections on seismic profiles.

[0189] Abandoned river channel microfacies: In well logging, it appears as a GR curve with abrupt changes in the upper part (box-shaped lower part + low-amplitude tooth-shaped upper part), and in seismic logging, the top of the lens body is covered by continuous weak-amplitude mudstone.

[0190] Natural levee microfacies: well logging curves show a low-amplitude sawtooth GR response, which manifests as weak-amplitude thin-layer reflections associated with the river channel in seismic data.

[0191] The identification markers of fluvial sedimentary microfacies are shown in Table 2.

[0192] Table 2:

[0193] sedimentary microfacies Earthquake reflection characteristics Well logging curve morphology Riverbed filling Incision Valley Filling Reflection Box-shaped or bell-shaped GR, resistivity suddenly increases Heart Beach Disordered / Hump-shaped reflections sawtooth resistivity beach Lateral product front reflection Bell-shaped GR, tapering upwards abandoned river channel weak amplitude filling reflection Top GR value suddenly increases natural embankment Intermittent parallel reflection Low-amplitude toothed GR

[0194] After identifying deltaic and fluvial sedimentary microfacies, the order of superiority of brine-retaining sand bodies in deltaic and fluvial sedimentary systems was determined based on grain size, single sand body thickness, and sand-to-land ratio. This evaluation assessed the mineralization brine reservoir space in both deltaic and fluvial sedimentary systems.

[0195] Different sedimentary microfacies sand bodies have different development characteristics. An ideal brine storage space requires sand bodies with good continuity and thickness. The larger the grain size, the higher the sand-to-land ratio, and the greater the thickness of a single sand body, the more conducive it is to brine storage.

[0196] (1) Ore-forming brine reservoir space in deltaic sedimentary systems

[0197] As shown in Table 3, the order of superiority of brine reservoir sand bodies in the deltaic sedimentary system is as follows: distributary channel microfacies, estuary bar microfacies, underwater distributary channel microfacies, crevice fan microfacies, and sheet sand microfacies.

[0198] Table 3:

[0199]

[0200] (2) Ore-forming brine reservoir space in fluvial sedimentary systems

[0201] As shown in Table 4, the order of superiority of brine reservoir sand bodies in river sedimentary systems is as follows: channel filling, mid-channel bar, side bar, abandoned channel, and natural levee.

[0202] Table 4:

[0203]

[0204] Based on the order of superiority of brine reservoir sand bodies in deltaic sedimentary systems and fluvial sedimentary systems, favorable exploration area types are further classified.

[0205] For deltaic sedimentary systems, the method for determining secondary favorable exploration areas is as follows:

[0206] If a dominant and favorable exploration area develops distributary channel microfacies, then the dominant and favorable exploration area is classified as a Class A dominant and favorable exploration area.

[0207] If the advantageous exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the advantageous exploration area will be classified as a Class B advantageous exploration area.

[0208] If the advantageous exploration area develops crevice fan microfacies and sheet sand microfacies, then the advantageous exploration area is classified as a Class C advantageous exploration area.

[0209] If a favorable exploration area develops distributary channel microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0210] If the favorable exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the favorable exploration area will be classified as a Class B favorable exploration area.

[0211] If the favorable exploration area develops crevice fan microfacies and sheet sand microfacies, then the favorable exploration area will be classified as a Class C favorable exploration area.

[0212] If a generally favorable exploration area develops distributary channel microfacies, then the generally favorable exploration area is classified as a Class A generally favorable exploration area.

[0213] If a generally favorable exploration area develops estuary bar microfacies and underwater distributary channel microfacies, then the generally favorable exploration area is classified as a Class B generally favorable exploration area.

[0214] If a generally favorable exploration area develops crevice fan microfacies or sheet-like sand microfacies, then the generally favorable exploration area is classified as a Class C generally favorable exploration area.

[0215] For fluvial sedimentary systems, the method for determining secondary favorable exploration areas is as follows:

[0216] If a favorable exploration area develops a channel-filling microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0217] If a favorable exploration area develops a center bar and a side bar, then the favorable exploration area is classified as a Class B favorable exploration area.

[0218] If the advantageous exploration area has developed abandoned river channels or natural levees, then the advantageous exploration area will be classified as a Class C advantageous exploration area.

[0219] If a favorable exploration area develops channel-filling microfacies, then the favorable exploration area is classified as a Class A favorable exploration area.

[0220] If a favorable exploration area develops a core bar and a side bar, then the favorable exploration area is classified as a Class B favorable exploration area.

[0221] If abandoned river channels or natural levees are developed in a favorable exploration area, then the favorable exploration area will be classified as a Class C favorable exploration area.

[0222] If a generally favorable exploration area develops channel-filling microfacies, then the generally favorable exploration area is classified as a Class A generally favorable exploration area.

[0223] If a generally favorable exploration area develops a center bar and a side bar, then the generally favorable exploration area is classified as a Class B generally favorable exploration area.

[0224] If a generally favorable exploration area has abandoned river channels or natural levees, then the generally favorable exploration area is classified as a Class C generally favorable exploration area.

[0225] Step S7: For the identified secondary favorable exploration areas, borehole verification is carried out, and the contents of K, Li, and B are analyzed by ICP-MS method to detect the physical property parameters of brine-type lithium-potassium-boron deposits.

[0226] This application, starting from the actual needs and metallogenic characteristics of brine-type lithium, potassium, and boron deposits, focuses on the key area of ​​tectonic transition zones in rift basins and innovatively proposes a multi-element coupled tectonic ore-controlling model. It combines a global paleoclimate database to accurately screen drought events, achieving rapid identification of target layers for lithium, potassium, and boron-rich brine exploration through paleoclimate-tectonic synergy. By fusing gravity, magnetic, and seismic data, it integrates key elements such as faults, deep and large faults, volcanic rocks, and differential subsidence to dynamically optimize favorable metallogenic tectonic units. Based on seismic data, it characterizes tectonic depressions and sedimentary facies to determine favorable exploration areas. Finally, through borehole verification and efficient ICP-MS detection technology, the grade of lithium, potassium, and boron deposits is determined. This forms an integrated evaluation system of "determination of target layers, optimization of favorable metallogenic tectonic units, optimization of favorable exploration areas, and borehole + geochemical verification," significantly improving the exploration efficiency of brine-type lithium, potassium, and boron resources in continental rift basins.

[0227] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0228] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for prospecting a lithium-potassium-boron brine deposit in a rift basin tectonic transition zone, characterized in that, The method comprises: Utilizing a global paleoclimate database, screening drought events experienced by the formation and evolution stage of the fault basin, and determining a potential ore-prospecting target layer; For the potential ore-prospecting target layer, determining an ore-prospecting target layer type according to an evaporite mineral thickness of the ore-prospecting target layer and a potassium-magnesium salt mineral proportion in the evaporite mineral of the ore-prospecting target layer; Obtaining gravity and magnetic data and seismic data of the fault basin, processing and geologically interpreting the gravity and magnetic data and the seismic data to obtain interpreted gravity and magnetic data and interpreted seismic data; identifying faults according to the interpreted gravity and magnetic data and the interpreted seismic data, and determining a first favorable ore-forming structural unit; and / or identifying deep faults according to the interpreted gravity and magnetic data and the interpreted seismic data, and determining a first favorable ore-forming structural unit; and / or identifying volcanic rock bodies according to the interpreted gravity and magnetic data and the interpreted seismic data, and determining a first favorable ore-forming structural unit; the first favorable ore-forming structural unit comprises a dominant favorable ore-forming structural unit, a good favorable ore-forming structural unit and a general favorable ore-forming structural unit; For the first favorable ore-forming structural unit, analyzing differential subsidence of adjacent structural units to determine a second favorable ore-forming structural unit; For the second favorable ore-forming structural unit, determining a low-lying area by utilizing seismic data, gravity and magnetic data, drilling data and outcrop data, and combining fault structures and volcanic rock body distribution ranges of the fault basin to determine a first favorable exploration area; For the first favorable exploration area, identifying fluvial facies and delta facies and sedimentary microfacies to determine a second favorable exploration area; For the determined second favorable exploration area, drilling verification is implemented, ICP-MS method is adopted to analyze K, Li and B contents, and physical property parameters of a brine-type lithium-potassium-boron deposit are detected.

2. The method of claim 1, wherein, The method comprises: According to the gravity and magnetic data of the fault basin, determining fault types and fault activity intensities of the tectonic transition zone of the fault basin; According to the seismic data of the fault basin, comparing the fault types and fault activity intensities of the tectonic transition zone of the fault basin determined according to the gravity and magnetic data, analyzing fault types, development characteristics and tectonic activity stages of the ore-prospecting target layer and surrounding layers; According to the fault types, development characteristics and tectonic activity stages of the ore-prospecting target layer and surrounding layers, determining a first favorable ore-forming structural unit.

3. The method of claim 2, wherein, The method comprises: Judging activity intensities of normal faults and detachment faults after the formation of the ore-prospecting target layer, if the activity intensities are strong or medium, the structural unit where the normal faults and the detachment faults are located is divided into a dominant favorable ore-forming structural unit; Judging an activity intensity of a reverse fault after the formation of the ore-prospecting target layer, if the activity intensity is weak, the structural unit where the reverse fault is located is divided into a dominant favorable ore-forming structural unit; Judging times of tectonic inversion and tectonic strike-slip of strike-slip faults and reverse faults, if the times are after the formation of the ore-prospecting target layer, the structural unit where the strike-slip faults and the reverse faults are located is divided into a dominant favorable ore-forming structural unit.

4. The method of claim 1, wherein, The method comprises: For the tectonic unit where the fault is located, the buried depth of the ore-prospecting target layer is determined, and the normal temperature of the ore-prospecting target layer is calculated according to the annual average temperature of the earth's surface; The well temperature of the ore-prospecting target layer is determined by collecting geophysical logging data of the tectonic unit where the fault is located; If the well temperature of the ore-prospecting target layer is greater than 140% of the normal temperature, the tectonic unit where the fault is located is divided into a superior favorable ore-forming tectonic unit; If the well temperature of the ore-prospecting target layer is greater than 120% and less than or equal to 140% of the normal temperature, the tectonic unit where the fault is located is divided into a good favorable ore-forming tectonic unit; If the well temperature of the ore-prospecting target layer is less than or equal to 120% of the normal temperature, the tectonic unit where the fault is located is divided into a general favorable ore-forming tectonic unit.

5. The method of claim 1, wherein, The identification of the deep fault and the determination of the first-level favorable ore-forming tectonic unit comprise: The spatial distribution and activity of the deep fault are identified through the collaborative analysis of the Bouguer gravity anomaly gradient zone and the vertical second-order derivative anomaly of the aeromagnetic anomaly; The fault geometry is further finely described through the coherence body and curvature attribute of the seismic data, the activity intensity is quantitatively represented according to the fault surface dip angle mutation and the growth stratum thickness ratio, and the development characteristics of the deep fault after the formation of the ore-prospecting target layer are analyzed; If the deep fault is a normal fault or a detachment fault after the formation of the ore-prospecting target layer, the tectonic unit where the deep fault is located is divided into a superior favorable ore-forming tectonic unit; If the deep fault is a strike-slip fault or a reverse fault after the formation of the ore-prospecting target layer, the tectonic unit where the deep fault is located is divided into a good favorable ore-forming tectonic unit.

6. The method of claim 1, wherein, The identification of the volcanic rock mass and the determination of the first-level favorable ore-forming tectonic unit comprise: The spatial form of the rock mass is determined through the combination analysis of gravity and magnetic anomalies and the boundary recognition enhanced by vertical derivative processing, and the volcanic rock and sedimentary rock or intrusive rock are identified; If the tectonic unit exists a volcanic rock mass, and the distribution range is greater than or equal to 1 / 5 of the area of the tectonic unit, the tectonic unit is divided into a superior favorable ore-forming tectonic unit; If the tectonic unit exists a volcanic rock mass, and the distribution range is greater than or equal to 1 / 10 and less than 1 / 5 of the area of the tectonic unit, the tectonic unit is divided into a good favorable ore-forming tectonic unit; If the tectonic unit exists a volcanic rock mass, and the distribution range is less than 1 / 10 of the area of the tectonic unit, the tectonic unit is divided into a general favorable ore-forming tectonic unit.

7. The method of claim 1, wherein, The analysis of the differential subsidence of adjacent tectonic units for the first-level favorable ore-forming tectonic unit and the determination of the second-level favorable ore-forming tectonic unit comprise: For the superior favorable ore-forming tectonic unit, if the adjacent tectonic unit has subsidence difference in a stratum below the ore-prospecting target layer, and the relative subsidence difference has been continuously existing since the formation of the subsidence difference, the footwall is divided into a class A superior favorable ore-forming tectonic unit; For the superior favorable ore-forming tectonic unit, if the adjacent tectonic unit has no subsidence difference in a stratum below the ore-prospecting target layer, but there is subsidence difference when the ore-prospecting target layer is formed, and the relative subsidence difference has been continuously existing thereafter, the footwall is divided into a class B superior favorable ore-forming tectonic unit; For a good favorable ore-forming tectonic unit, if the adjacent tectonic unit has a subsidence difference in a stratum below the target stratum, but the subsidence difference ends after the formation of the target stratum, the footwall is divided into a class A good favorable ore-forming tectonic unit; For a good favorable ore-forming tectonic unit, if the adjacent tectonic unit has no subsidence difference in a stratum below the target stratum and the target stratum, but there is a subsidence difference when the target stratum is formed, and the subsidence difference ends after the formation of the target stratum, the footwall is divided into a class B good favorable ore-forming tectonic unit; For a general favorable ore-forming tectonic unit, if the adjacent tectonic unit has no subsidence difference in a stratum below the target stratum and the target stratum, but there is a subsidence difference after the formation of the target stratum, and the relative subsidence difference continues thereafter, the footwall is divided into a class A general favorable ore-forming tectonic unit; For a general favorable ore-forming tectonic unit, if the adjacent tectonic unit has no subsidence difference in a stratum below the target stratum and the target stratum, but there is a subsidence difference after the formation of the target stratum, but the subsidence difference ends thereafter, the footwall is determined to be a class B general favorable ore-forming tectonic unit.

8. The method of claim 1, wherein, For the secondary favorable ore-forming tectonic unit, a low-lying area is determined by using seismic data, gravity and magnetic data, drilling data and outcrop data, a primary favorable exploration area is determined in combination with the fault structure of the faulted basin and the distribution range of the volcanic rock mass, and the primary favorable exploration area comprises: a basement depression area is preliminarily circled by identifying faults, basement interfaces and sedimentary layer thicknesses through seismic reflection profile interpretation; gravity low anomalies and magnetic gentle areas are extracted by processing gravity and magnetic data, and are verified in comparison with the seismic basement depth; the spatial form of the low-lying area is accurately depicted by using the seismic interpretation result to constrain gravity and magnetic joint inversion and fitting the measured data; the low-lying area is comprehensively determined in combination with drilling data and outcrop data calibration; the spatial relationship between the low-lying area and normal faults and volcanic rock masses in the same favorable ore-forming tectonic unit is compared; if the low-lying area is located around the normal faults and the volcanic rock masses, the low-lying area is determined to be a dominant favorable exploration area; if the low-lying area is located around the normal faults or the volcanic rock masses, the low-lying area is determined to be a good favorable exploration area; if the low-lying area is within 50 km from the normal faults or the volcanic rock masses, the low-lying area is determined to be a general favorable exploration area.

9. The method of claim 8, wherein, For the primary favorable exploration area, a secondary favorable exploration area is determined by identifying river facies and delta facies and sedimentary microfacies, and the secondary favorable exploration area comprises: sand bodies interpreted by well logging are matched with seismic facies by well-to-seismic calibration, river facies and delta facies are identified in combination with seismic attributes and regional sedimentary background; delta facies sedimentary microfacies are identified according to delta facies sedimentary microfacies identification marks; river facies sedimentary microfacies are identified according to river facies sedimentary microfacies identification marks; According to the particle size, single sand body thickness and sand ratio, the delta sedimentary system brine reservoir sand body order and the river sedimentary system brine reservoir sand body order are determined; the delta sedimentary system brine reservoir sand body order is in turn: distributary channel microfacies, river mouth bar microfacies, underwater distributary channel microfacies, crevasse splay microfacies, sheet sand microfacies; the river sedimentary system brine reservoir sand body order is in turn: channel filling, heart beach, side beach, abandoned channel, natural dam; According to the delta sedimentary system brine reservoir sand body order and the river sedimentary system brine reservoir sand body order, the secondary favorable exploration area is determined.

10. The method of claim 9, wherein, The delta sedimentary system brine reservoir sand body order and the river sedimentary system brine reservoir sand body order determine the secondary favorable exploration area, comprising: For the delta sedimentary system, the method for determining the secondary favorable exploration area is as follows: If the advantage favorable exploration area develops the distributary channel microfacies, the advantage favorable exploration area is determined as the A-type advantage favorable exploration area; If the advantage favorable exploration area develops the river mouth bar microfacies and the underwater distributary channel microfacies, the advantage favorable exploration area is determined as the B-type advantage favorable exploration area; If the advantage favorable exploration area develops the crevasse splay microfacies and the sheet sand microfacies, the advantage favorable exploration area is determined as the C-type advantage favorable exploration area; If the good favorable exploration area develops the distributary channel microfacies, the good favorable exploration area is determined as the A-type good favorable exploration area; If the good favorable exploration area develops the river mouth bar microfacies and the underwater distributary channel microfacies, the good favorable exploration area is determined as the B-type good favorable exploration area; If the good favorable exploration area develops the crevasse splay microfacies and the sheet sand microfacies, the good favorable exploration area is determined as the C-type good favorable exploration area; If the general favorable exploration area develops the distributary channel microfacies, the general favorable exploration area is determined as the A-type general favorable exploration area; If the general favorable exploration area develops the river mouth bar microfacies and the underwater distributary channel microfacies, the general favorable exploration area is determined as the B-type general favorable exploration area; If the general favorable exploration area develops the crevasse splay microfacies and the sheet sand microfacies, the general favorable exploration area is determined as the C-type general favorable exploration area; For the river sedimentary system, the method for determining the secondary favorable exploration area is as follows: If the advantage favorable exploration area develops the channel filling microfacies, the advantage favorable exploration area is determined as the A-type advantage favorable exploration area; If the advantage favorable exploration area develops the heart beach and the side beach, the advantage favorable exploration area is determined as the B-type advantage favorable exploration area; If the advantage favorable exploration area develops the abandoned channel and the natural dam, the advantage favorable exploration area is determined as the C-type advantage favorable exploration area; If the good favorable exploration area develops the channel filling microfacies, the good favorable exploration area is determined as the A-type good favorable exploration area; If the good favorable exploration area develops the heart beach and the side beach, the good favorable exploration area is determined as the B-type good favorable exploration area; If the good favorable exploration area develops the abandoned channel and the natural dam, the good favorable exploration area is determined as the C-type good favorable exploration area; If the general favorable exploration area develops the channel filling microfacies, the general favorable exploration area is determined as the A-type general favorable exploration area; If the general favorable exploration area develops the heart beach and the side beach, the general favorable exploration area is determined as the B-type general favorable exploration area; If the abandoned river channel and natural dike are developed in the general favorable exploration area, the general favorable exploration area is determined as the C type general favorable exploration area.

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