Reverse interlayer oxidation zone identification method

Abstract

The invention belongs to the technical field of sandstone type uranium ore prospecting, and particularly relates to a reverse interlayer oxidation zone identification method. Comprising the following five steps: step 1, measuring stratum occurrence at an earth surface outcrop position by using a geological compass; 2, research drilling hole selection; 3, drawing a geological profile map; 4, the geochemical environment of the same sand body of each drill hole is judged; and step 5, according to the relation of the reduction zone elevation (h1), the transition zone elevation (h2) and the oxidation zone elevation (h3), if h2 is greater than h1 and greater than h3, judging that the oxidation zone is a reverse interlayer oxidation zone. According to the method, the sandstone-type uranium ore reversal interlayer oxidation zone can be effectively identified, the method is simple and efficient, the uranium ore exploration direction is effectively indicated, the sandstone-type uranium ore prospecting thought is clarified, and the uranium ore prospecting success rate is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of sandstone-type uranium ore prospecting and relates to a reverse interlayer oxidation zone identification method. Background Art

[0002] Generally, oxygenated water migrates along the gently inclined slope of the basin, and oxygen gradually decreases with the action of reducing agents. As the distance increases, the oxygen in the water disappears completely after migrating to a certain depth, and a transition zone is formed near the exhaustion of oxygen. This is the positive interlayer oxidation zone, that is, the interlayer oxidation zone is always higher than the transition zone and the primary zone. However, in the Qiulitage area on the northern edge of the Tarim Basin, an inverted interlayer oxidation zone was found due to tectonic tilting, that is, the primary zone is higher than the transition zone, and the transition zone is higher than the oxidation zone, which is the opposite.

[0003] In the process of uranium prospecting, if the inversion interlayer oxidation zone cannot be correctly identified and the development direction of the oxidation zone is not clear, it will often lead to the prospecting direction going in the opposite direction, the prospecting ideas will be confused and unclear, and the uranium exploration work will be seriously affected. Summary of the invention

[0004] The main purpose of the present invention is to provide a reverse interlayer oxidation zone identification method to determine the development direction of the interlayer oxidation zone and determine the prospecting direction of sandstone-type uranium deposits.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for identifying an inverted interlayer oxidation zone includes five steps:

[0007] Step 1, using a geological compass, measure the occurrence of the strata at the outcrop location on the surface;

[0008] Step 2, study the drilling selection;

[0009] Step 3, draw a geological profile;

[0010] Step 4, identifying the geochemical zone where the same sand body in each borehole is located;

[0011] Step 5, based on the relationship among the reduction zone elevation (h1), the transition zone elevation (h2), and the oxidation zone elevation (h3), if h1>h2>h3, it is identified as an inversion interlayer oxidation zone.

[0012] The step 1 is to measure the occurrence of the strata at the surface outcrop position using a geological compass;

[0013] It is required to find a good outcrop location of the target layer on the surface within the selected uranium exploration area, and use a geological compass to accurately measure the rock formation occurrence elements, including dip, strike and inclination.

[0014] Step 2, studying the selection of drilling holes;

[0015] It is required that several sandstone-type interlayer oxidation zone uranium ore drilling holes have been constructed in the exploration area, and the requirements for the selected holes are: the drilling holes all expose the same target layer sand body; the number of selected drilling holes is ≥3; the drilling holes must be selected along the dip direction of the formation.

[0016] The step 3 is to draw a geological profile;

[0017] Combined with regional geological data, the stratigraphic marker layer is determined, and the multiple boreholes selected in step 2 are divided through stratigraphic comparative analysis using geological theory. The top and bottom plates of the sand bodies in the same layer in the boreholes are connected to draw a geological profile.

[0018] The step 4 is to identify the geochemical environment of the same sand body in each borehole;

[0019] There are three possible geochemical environments for sand bodies, namely, primary zone, transition zone, and oxidation zone. If the sand body exposed by drilling is mainly gray, the uranium content is less than 0.005%, and the Fe content in the rock is 2+ / Fe 3+ If the value is greater than 1.2 and the Th / U value is between 0.5 and 1.5, it can be identified as a primary zone; if the sandstone rock exposed in the drilling hole is dark gray, gray with yellow, red lumps, spots, and the uranium content is ≥0.005%, there is abnormal uranium content, mineralization or industrial grade, Fe 2+ / Fe 3+ The value is between 0.5 and 1.2, and the Th / U value is less than 0.5, which is identified as a transition zone. If the sandstone rock exposed in the drilling hole is oxidized red or yellow, and the uranium content is less than the uranium content in the primary zone, the rock Fe 2+ / Fe 3+ When the value is less than 0.5 and the Th / U value is greater than 1.5, it is identified as an oxidation zone.

[0020] In step 5, according to the relationship among the elevation of the reduction zone (h1), the elevation of the transition zone (h2), and the elevation of the oxidation zone (h3), if h1>h2>h3, it is identified as an inversion interlayer oxidation zone;

[0021] According to step 4, the geochemical environment of the same sand body in each borehole is identified, and the formula: h = Za is used to calculate the elevation of the different geochemical environments of each borehole, that is, the elevation position of the primary zone, transition zone, and oxidation zone. The spatial position relationship between the primary zone, transition zone, and oxidation zone is determined through the elevation data. If h1>h2>h3, it can be determined as an inverted interlayer oxidation zone.

[0022] Where h is the elevation of a certain point in the borehole;

[0023] h1 is the elevation of the primary zone revealed by the drilling;

[0024] h2 is the elevation of the transition zone revealed by the drilling;

[0025] h2 is the elevation of the oxidation zone exposed by the drill hole;

[0026] Z is the elevation of the borehole mouth;

[0027] a is the burial depth of a certain point in the borehole.

[0028] The beneficial effects of the present invention are that the inverted interlayer oxidation zone of sandstone-type uranium ore can be effectively identified, and the method is simple and efficient, which can effectively indicate the direction of uranium ore exploration, clarify the prospecting ideas of sandstone-type uranium ore, and improve the success rate of uranium ore prospecting. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Attached Figure 1 A flow chart of a method for identifying an inverted interlayer oxidation zone;

[0030] Attached Figure 2 Drilling profile of a typical inverted interlayer oxidation zone type uranium deposit in the Zhidalik area; DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 As shown, the present invention provides a method for identifying an inverted interlayer oxidation zone, which specifically comprises the following steps:

[0033] Step 1: Use a geological compass to measure the occurrence of strata at the outcrop location on the surface. In the uranium exploration area, find a good outcrop location of the target layer on the surface and use a geological compass to accurately measure the occurrence elements of the rock strata, including dip, strike and inclination.

[0034] For example, the lower section of the Kuche Formation in the Zhidalike area on the northern edge of the Tarim Basin was selected as the research object. At a good outcrop position of the target layer, the stratum dip was measured using a geological compass and was found to be 10°∠29°.

[0035] Step 2, study the selection of boreholes, which requires that several sandstone-type interlayer oxidation zone uranium mines have been constructed in the exploration area. The requirements for the selected holes are: the boreholes all expose the same target layer sand body; the number of selected boreholes is ≥3; the boreholes must be selected along the dip direction of the formation.

[0036] For example, in the Zhidalik area on the northern edge of the Tarim Basin, predecessors have constructed multiple uranium exploration boreholes. Drill hole 1, drill hole 2, and drill hole 3 were selected in sequence along the direction of the formation dip (10°) to expose the same sand body in the lower section of the Kuche Formation.

[0037] Step 3, draw a geological profile, combine regional geological data, determine the stratigraphic marker layer, use geological theory to divide the multiple boreholes selected in step 2 through stratigraphic comparative analysis, connect the top and bottom plates of the sand bodies in the same layer in the boreholes, and draw a geological profile.

[0038] For example, in the Zhidalik area on the northern edge of the Tarim Basin, the three selected boreholes, borehole 1, borehole 2, and borehole 3, were connected to draw a geological profile, with thick interlayers of mudstone and sandstone as the mark.

[0039] Step 4: Identify the geochemical environment of the same sand body in each borehole. There are three possible geochemical environments for sand bodies, namely, primary zone, transition zone, and oxidation zone. If the sand body exposed by drilling is mainly gray, the uranium content is less than 0.005%, and the Fe content in the rock is 2+ / Fe 3 + If the value is greater than 1.2 and the Th / U value is between 0.5 and 1.5, it can be identified as a primary zone; if the sandstone rock exposed in the drilling hole is dark gray, gray with yellow, red lumps, spots, and the uranium content is ≥0.005%, there is abnormal uranium content, mineralization or industrial grade, Fe 2+ / Fe 3+ The value is between 0.5 and 1.2, and the Th / U value is less than 0.5, which is identified as a transition zone. If the sandstone rock exposed in the drilling hole is oxidized red or yellow, and the uranium content is less than the uranium content in the primary zone, the rock Fe 2+ / Fe 3+ When the value is less than 0.5 and the Th / U value is greater than 1.5, it is identified as an oxidation zone.

[0040] For example, in the Zhidalik area on the northern edge of the Tarim Basin, the selected borehole 1 exposed gray sandstone with a uranium content of 0.002% and Fe 2+ / Fe 3+ The value is 1.34, and the Th / U value is 0.89, which identifies the primary zone sandstone; the selected drilling hole 2 exposed dark gray sandstone, with partly light yellow blocks, and the uranium content is 0.0124%, reaching the industrial grade, and Fe 2+ / Fe 3+ The value is 0.97, and the Th / U value is 0.31, which is identified as a transition zone; the selected drill hole 3 exposed yellow sandstone with a uranium content of 0.001%, Fe 2+ / Fe 3+ The value is 0.0.32, and the Th / U value is 2.5, which is judged to be an oxidation zone.

[0041] Step 5, according to the relationship between the elevation of the reduction zone (h1), the elevation of the transition zone (h2), and the elevation of the oxidation zone (h3), if h1>h2>h3, it is identified as an inverted interlayer oxidation zone. According to the formula: h=Za, the elevations of different geochemical environments of each borehole are calculated, that is, the elevation positions of the primary zone, transition zone, and oxidation zone. Through the elevation data, the spatial position relationship between the primary zone, transition zone, and oxidation zone is judged. If h1>h2>h3, it can be determined as an inverted interlayer oxidation zone.

[0042] Where h is the elevation of a certain point in the borehole;

[0043] h1 is the elevation of the primary zone revealed by the drilling;

[0044] h2 is the elevation of the transition zone revealed by the drilling;

[0045] h2 is the elevation of the oxidation zone exposed by the drill hole;

[0046] Z is the elevation of the borehole mouth;

[0047] a is the burial depth of a certain point in the borehole.

[0048] For example, in the Zhidalik area on the northern edge of the Tarim Basin, the elevation of the reduction zone revealed by the selected borehole 1 is h1=Z1-a1=1387.50m-168.50m=1219m; the elevation of the transition zone revealed by borehole 2 is h2=Z2-a2=1352.00m-302.00m=1050m; the elevation of the oxidation zone revealed by borehole 3 is h3=Z3-a3=1333.00m-422.00m=911.00m. It can be seen that h1>h2>h3, and it is identified as an inversion interlayer oxidation zone based on the three spatial position relationships.

Claims

1. A method for identifying an inverted interlayer oxidation zone, characterized in that: The method consists of five steps: Step 1, using a geological compass, measure the occurrence of the strata at the outcrop location on the surface; Step 2, study the drilling selection; Step 3, draw a geological profile; Step 4, identifying the geochemical environment of the same sand body in each borehole; Step 5, based on the relationship among the reduction zone elevation (h1), the transition zone elevation (h2), and the oxidation zone elevation (h3), if h1>h2>h3, it is identified as an inversion interlayer oxidation zone.

2. A method for identifying an inverted interlayer oxidation zone according to claim 1, characterized in that: In step 1, a geological compass is used to measure the occurrence of strata at the outcrop position on the surface. It is required to find a good outcrop position of the target layer on the surface within the selected uranium exploration area, and use a geological compass to accurately measure the occurrence elements of the strata, including dip, strike and inclination.

3. A method for identifying an inverted interlayer oxidation zone as claimed in claim 2, characterized in that: In the step 2, the selection of drilling holes is studied, and it is required that several sandstone interlayer oxidation zone uranium ore drilling holes have been constructed in the exploration area, and the requirements for the selected holes are: the drilling holes all expose the same target layer sand body; The number of selected boreholes shall be ≥ 3; the boreholes shall be selected along the dip direction of the formation.

4. A method for identifying an inverted interlayer oxidation zone as claimed in claim 3, characterized in that: Drawing a geological profile in step 3 requires combining regional geological data to determine the stratigraphic marker layer, dividing the multiple boreholes selected in step 2 by stratigraphic comparative analysis using geological theory, connecting the top and bottom plates of the sand bodies in the same layer in the boreholes, and drawing a geological profile.

5. A method for identifying an inverted interlayer oxidation zone as claimed in claim 4, characterized in that: In step 4, the geochemical environment of the same sand body in each borehole is identified. There are three possible geochemical environments for sand bodies, namely, the primary zone, the transition zone, and the oxidation zone. If the sand body exposed by the drilling is mainly gray, the uranium content is less than 0.005%, and the Fe content in the rock is less than 0.005%, the sand body is mainly gray, and the uranium content is less than 0.005%. 2+ / Fe 3+ If the value is greater than 1.2 and the Th / U value is between 0.5 and 1.5, it can be identified as a primary zone; if the sandstone rock exposed in the drilling hole is dark gray, gray with yellow, red lumps, spots, and the uranium content is ≥0.005%, there is abnormal uranium content, mineralization or industrial grade, Fe 2+ / Fe 3+ The value is between 0.5 and 1.2, and the Th / U value is less than 0.5, which is identified as a transition zone. If the sandstone rock exposed in the drilling hole is oxidized red or yellow, and the uranium content is less than the uranium content in the primary zone, the rock Fe 2+ / Fe 3+ When the value is less than 0.5 and the Th / U value is greater than 1.5, it is identified as an oxidation zone.

6. A method for identifying an inverted interlayer oxidation zone as claimed in claim 5, characterized in that: In step 5, according to the relationship among the reduction zone elevation (h1), the transition zone elevation (h2), and the oxidation zone elevation (h3), if h1>h2>h3, it is determined to be an inverted interlayer oxidation zone. According to step 4, the geochemical environment of the same sand body in each borehole is determined, and the formula: h=Za is used to calculate the elevations of different geochemical environments of each borehole, that is, the elevation positions of the primary zone, transition zone, and oxidation zone. The spatial position relationship among the primary zone, transition zone, and oxidation zone is determined by the elevation data. If h1>h2>h3, it can be determined to be an inverted interlayer oxidation zone. Where h is the elevation of a certain point in the borehole; h1 is the elevation of the primary zone revealed by the drilling; h2 is the elevation of the transition zone revealed by the drilling; h2 is the elevation of the oxidation zone exposed by the drill hole; Z is the elevation of the borehole mouth; a is the burial depth of a certain point in the borehole.

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