A method for distinguishing ore deposit types using tourmaline element composition

Abstract

The invention discloses a method for distinguishing the type of a ore deposit by using tourmaline element components. The method comprises the following steps: collecting hydrothermal tourmaline samples in the ore deposit, determining the content data of trace elements of Sn, Li, Ga and V, taking F1, F2 and F3 as distinguishing factors, combining the characteristics that a porphyry Cu-Mo-Au ore deposit has relatively low Sn+Li, further, a porphyry Cu-Mo ore deposit has relatively high Ga*V, and a porphyry Au ore deposit has relatively low Ga*V; a Sn-W ore deposit related to granite has relatively high Sn+Li; and an IOCG ore deposit has relatively high Sn+Li and Ga*V, and distinguishing the type of the ore deposit, realizing rapid distinction of the ore deposit type in the process of prospecting and exploration, shortening the exploration period, and reducing the exploration cost. The method can be used for identifying four different types of ore deposits, and is an economical, efficient and green new prospecting method.

Description

Technical Field

[0001] The invention belongs to the field of mineral deposit exploration and evaluation, and in particular relates to a method for distinguishing mineral deposit types by utilizing tourmaline components. Background Art

[0002] Porphyry deposits refer to fine-veined and impregnated ore bodies that are widely distributed in porphyry rock bodies and their vicinity. Porphyry deposits occupy an extremely important position in the world's ore deposit types. At present, porphyry copper deposits supply nearly 75% of the world's copper, 50% of molybdenum and 20% of gold. China's terrestrial porphyry deposits include porphyry Cu (-Mo, -Au), porphyry Mo, porphyry Au and porphyry Pb-Zn. Sn and W are important strategic minerals in my country, and granite-related Sn-W deposits are their main sources. Iron Oxide-Copper-Gold (IOCG) deposits are an important type of deposit proposed in the past 20 years. This type of deposit has huge reserves, contains a large amount of low-Ti iron oxides and is associated with Cu and Au of great economic value, and is enriched in metals such as REE, U, P and Co to varying degrees, and has significant scientific research value and exploration significance.

[0003] At present, the traditional method of determining the type of mineral deposit mainly relies on rock geochemical measurement, large-scale rock-alteration-mineralization mapping, drilling verification, etc. However, these methods require a lot of manpower and funds, have a long cycle and high cost, and cannot meet the urgent needs of rapid exploration and evaluation.

[0004] Therefore, it is necessary to find an accurate, economical and efficient method to identify the type of mineral deposits. Summary of the invention

[0005] The purpose of the present invention is to provide a method for quickly distinguishing the type of ore deposits by using tourmaline components, thereby realizing the rapid distinction of the type of ore deposits during prospecting and exploration, shortening the exploration period, and reducing the exploration cost. The method can be used to identify four different types of ore deposits, and is an economical, efficient, and green new prospecting method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for quickly identifying the type of a ore deposit using tourmaline components is provided, comprising the following steps:

[0008] 1) Sample collection

[0009] Identify tourmaline in deposits, differentiate between magmatic and hydrothermal tourmaline, and collect samples of hydrothermal tourmaline;

[0010] 2) Sample preparation and testing

[0011] Prepare the hydrothermal tourmaline samples collected in step 1) into probe slices, conduct in-situ micro-area element analysis and data processing to obtain the content data of trace elements Sn, Li, Ga, and V in the hydrothermal tourmaline, denoted as c(Sn), c(Li), c(Ga), and c(V);

[0012] 3) Use F1, F2, and F3 as discriminant factors to conduct deposit type discrimination, specifically:

[0013] F1 = 0.001 * (3 * c(Sn) + c(Li)) 2.7 (Formula 1)

[0014] F2 = 5 * 10 16 * (3 * c(Sn) + c(Li)) -3.5 (Formula 2)

[0015] F3 = 2 * 10 6 * (3 * c(Sn) + c(Li)) -1.0 (Formula 3);

[0016] Substitute the contents of Sn and Li into Formulas 1, 2, and 3 to calculate the discriminant factors F1, F2, and F3 respectively, where:

[0017] When c(Ga) * c(V) < F1 and c(Ga) * c(V) < F2, then discriminate that the deposit is Sn-W related to granite;

[0018] When c(Ga) * c(V) > F2, then discriminate that the deposit is IOCG-type Au;

[0019] When F1 < c(Ga) * c(V) < F3, then discriminate that the deposit is porphyry-type Au;

[0020] When c(Ga) * c(V) > F1, c(Ga) * c(V) > F3 and c(Ga) * c(V) < F2, then discriminate that the deposit is porphyry-type Cu-Mo;

[0021] Among them, the specific steps to obtain the discriminant factors F1, F2, and F3 are:

[0022] ① Sample collection

[0023] Identify tourmaline in porphyry-type Cu-Mo deposits, porphyry-type Au deposits, Sn-W deposits related to granite, and IOCG-type Au deposits respectively, distinguish magmatic tourmaline and hydrothermal tourmaline, and collect hydrothermal tourmaline samples from different deposits;

[0024] ② Sample preparation and testing

[0025] The hydrothermal tourmaline sample collected in step ① is prepared as a probe sheet, and in-situ micro-area element analysis and data processing are performed to obtain the content data of trace elements Sn, Li, Ga, and V in the hydrothermal tourmaline, which are recorded as c(Sn), c(Li), c(Ga), and c(V);

[0026] ③ Obtain the discriminant factors F1, F2, F3

[0027] The projection is carried out with 3*c(Sn)+c(Li) as the horizontal coordinate and c(Ga)*c(V) as the vertical coordinate. The boundary lines of different deposit types are obtained according to the projection range, and the discrimination factors F1-F3 are obtained, among which:

[0028] F1=0.001*(3*c(Sn)+c(Li)) 2.7 (Formula 1)

[0029] F2=5*10 16 *(3*c(Sn)+c(Li)) -3.5 (Formula 2)

[0030] F3=2*10 6 *(3*c(Sn)+c(Li)) -1.0 (Formula 3).

[0031] According to the above scheme, in step 1), the standard for distinguishing magmatic tourmaline from hydrothermal tourmaline is that magmatic tourmaline is produced in a weakly altered rock mass in the form of dissemination, while hydrothermal tourmaline is produced in a vein form or is formed in a strongly altered rock.

[0032] According to the above scheme, in the step 2), laser ablation inductively coupled plasma mass spectrometry in-situ micro-area element analysis is carried out on the tourmaline sample, and the test elements include Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, and U.

[0033] According to the above scheme, in step 2), the test data is processed using ICPMSDataCal software to obtain data in Excel format.

[0034] Preferably, in the test process, it is possible that magmatic tourmaline is detected or mis-detected, and the test data is eliminated using the following standards: B>10000ppm eliminates mis-detected or penetrated data; Ba<0.6ppm eliminates magmatic tourmaline; and finally, the tourmaline trace data is obtained.

[0035] The working principle of the method of the present invention is:

[0036] Tourmaline is a common accessory mineral that can be formed in different types of deposits, such as porphyry Cu-Mo-Au deposits, Sn-W deposits associated with granite, IOCG Au deposits, etc. Based on the response of the changes in trace elements in tourmaline to factors such as the composition of ore-forming fluids, surrounding rock characteristics, temperature, pH value, etc., which are closely related to different types of deposits, whether the changes in trace elements in tourmaline can be used to indicate different types of deposits. Based on the above principles and ideas, the present invention, on the basis of a large amount of hydrothermal tourmaline data, through systematic analysis and comparison, found that porphyry Cu-Mo-Au deposits have lower Sn+Li, further, porphyry Cu-Mo deposits have higher Ga*V, while porphyry Au deposits have relatively low Ga*V; Sn-W deposits associated with granite have relatively high Sn+Li; and IOCG deposits have relatively high Sn+Li and Ga*V. On the basis of the above rules, a formula for quantitatively distinguishing different types of mineral deposits was further fitted, which enabled rapid identification of mineral deposit types during prospecting and exploration, shortened the exploration cycle, and reduced exploration costs. It is an economical, efficient, and green new method for prospecting.

[0037] The beneficial effects of the present invention are:

[0038] The present invention provides a method for distinguishing the type of ore deposits by using the trace element components of tourmaline. By using advanced in-situ analysis technology, the mineral tourmaline, which is commonly present in hydrothermal deposits, is upgraded from a qualitative description to a quantitative explanation, and the changes in its trace elements are linked to different types of ore deposits. In a newly discovered ore deposit, the type of the ore deposit can be quickly distinguished by the tourmaline components, further guiding the direction of mineral exploration and effectively shortening the ore deposit exploration cycle. The method can identify four different types of ore deposits, is economical and efficient, and has broad prospects for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a diagram illustrating the use of tourmaline components to distinguish mineral deposit types in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] Example 1

[0042] Obtain the discriminant factors F1-F3. The specific steps are:

[0043] (1) Sample collection

[0044] First, tourmaline was identified in porphyry Cu-Mo deposits, porphyry Au deposits, granite-related Sn-W deposits, and IOCG-type Au deposits. Second, magmatic tourmaline and hydrothermal tourmaline were distinguished. The specific characteristics are as follows: magmatic tourmaline is generally produced in weakly altered rock bodies in the form of disseminated, while hydrothermal tourmaline is generally produced in veins or formed in strongly altered rocks. Finally, samples containing hydrothermal tourmaline were collected.

[0045] (2) Sample preparation and testing

[0046] The sample containing tourmaline was prepared as a probe sheet, the tourmaline was identified under a microscope, and marked with a marker. The tourmaline with complete crystal development and large particles that met the test conditions was selected for in-situ micro-area element analysis by laser ablation inductively coupled plasma mass spectrometry. The test elements include Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, and U.

[0047] (3) Data processing and interpretation

[0048] The test data was processed using ICPMSDataCal software to obtain data in Excel format. Furthermore, it is possible that magmatic tourmaline was detected or mis-detected during the test. The test data was eliminated using the following criteria: B>10000ppm to eliminate mis-detected or perforated data; Ba<0.6ppm to eliminate magmatic tourmaline. Finally, the trace data of tourmaline was obtained.

[0049] (4) Obtain the calculation formula of the discriminant factors F1, F2, and F3

[0050] The data obtained in step (3) were processed using Excel. The trace element analysis of tourmaline Sn, Li, Ga, and V was performed. The contents of trace elements Sn, Li, Ga, and V in tourmaline were defined as c(Sn), c(Li), c(Ga), and c(V).

[0051] Project the graph with 3*c(Sn)+c(Li) as the horizontal coordinate and c(Ga)*c(V) as the vertical coordinate, such as Figure 1 As shown in the figure, the boundary lines of different ore deposit types are obtained according to the projection range, and the discrimination factors F1-F3 are calculated using the following formula; where:

[0052] F1=0.001*(3*c(Sn)+c(Li)) 2.7 (Formula 1);

[0053] F2=5*10 16*(3*c(Sn)+c(Li)) -3.5 (Formula 2);

[0054] F3 = 2*10 6 *(3*c(Sn)+c(Li)) -1.0 (Formula 3).

[0055] (5) Ore deposit type discrimination method

[0056] According to the methods in steps (1) and (2), obtain the content data of trace elements Sn, Li, Ga, and V in the hydrothermal tourmaline to be measured, denoted as c(Sn), c(Li), c(Ga), and c(V); substitute the contents of Sn and Li into the above Formulas 1, 2, and 3, and calculate the discrimination factors F1, F2, and F3 respectively; where:

[0057] When c(Ga)*c(V) < F1 and c(Ga)*c(V) < F2, then discriminate that the ore deposit is granite-related Sn-W;

[0058] When c(Ga)*c(V) > F2, then discriminate that the ore deposit is IOCG-type Au;

[0059] When F1 < c(Ga)*c(V) < F3, then discriminate that the ore deposit is porphyry-type Au;

[0060] When c(Ga)*c(V) > F1, c(Ga)*c(V) > F3, and c(Ga)*c(V) < F2, then discriminate that the ore deposit is porphyry-type Cu-Mo.

[0061] Example 2:

[0062] Use tourmaline composition to discriminate the ore deposit type: Take the Beimulang porphyry Cu-Mo ore deposit in Tibet as an example, and the specific steps are as follows:

[0063] a. Sample collection: On the surface and in boreholes of Beimulang, collect samples containing hydrothermal tourmaline according to the occurrence state of tourmaline.

[0064] b. Sample treatment: Grind the collected samples into probe slices, and circle the tourmaline minerals under the microscope.

[0065] c. Sample testing: Use a laser ablation inductively coupled plasma mass spectrometry instrument to test the trace elements of tourmaline, conduct trace element analysis of tourmaline, and obtain the content data of Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, and U.

[0066] d. Data processing: Use ICPMSDataCal software for data analysis and processing.

[0067] e. Distinguishing the type of ore deposit: The final data after processing by Excel is shown in Table 1. The discriminant factors F1, F2 and F3 are calculated according to formulas 1-3 in Example 1. Then, based on the calculation results of the discriminant factors F1, F2 and F3 and the discrimination method of step (5) of Example 1, it is discriminated that the North Mulang tourmaline collected this time belongs to the porphyry type Cu-Mo deposit, which is consistent with the geological facts, further proving the effectiveness of the new method proposed this time for distinguishing the type of ore deposit based on tourmaline components.

[0068] Table 1 Results of trace element data of some tourmaline in the Beimulang deposit in Tibet

[0069]

[0070]

[0071]

[0072]

[0073] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for quickly identifying the type of ore deposit using tourmaline components, characterized in that: It includes the following steps: 1) Sample collection Identify tourmaline in the ore deposit, distinguish magmatic tourmaline from hydrothermal tourmaline, and collect hydrothermal tourmaline samples; 2) Sample preparation and testing Prepare the hydrothermal tourmaline samples collected in step 1) into probe slices, conduct in-situ microarea element analysis and data processing to obtain the content data of trace elements Sn, Li, Ga, and V in the hydrothermal tourmaline, denoted as c(Sn), c(Li), c(Ga), and c(V); 3) Use F1, F2, and F3 as discrimination factors to discriminate the ore deposit type, specifically: F1=0.001*(3*c(Sn)+c(Li)) 2.7 (Formula 1) F2=5*10 16 *(3*c(Sn)+c(Li)) -3.5 (Formula 2) F3=2*10 6 *(3*c(Sn)+c(Li)) -1.0 (Formula 3); Substitute the Sn and Li contents into Formula 1, Formula 2, and Formula 3 to calculate the discrimination factors F1, F2, and F3 respectively, where: When c(Ga)*c(V) < F1 and c(Ga)*c(V) < F2, then discriminate that the ore deposit is Sn-W related to granite; When c(Ga)*c(V) > F2, then discriminate that the ore deposit is IOCG-type Au; When F1 < c(Ga)*c(V) < F3, then discriminate that the ore deposit is porphyry-type Au; When c(Ga)*c(V) > F1, c(Ga)*c(V) > F3, and c(Ga)*c(V) < F2, then discriminate that the ore deposit is porphyry-type Cu-Mo; Among them, the specific steps to obtain the discrimination factors F1, F2, and F3 are: ① Sample collection Identify tourmaline in porphyry-type Cu-Mo deposits, porphyry-type Au deposits, Sn-W deposits related to granite, and IOCG-type Au deposits respectively, distinguish magmatic tourmaline from hydrothermal tourmaline, and collect hydrothermal tourmaline samples of different ore deposits; ② Sample preparation and testing Prepare the hydrothermal tourmaline samples collected in step ① into probe slices, conduct in-situ microarea element analysis and data processing to obtain the content data of trace elements Sn, Li, Ga, and V in the hydrothermal tourmaline, denoted as c(Sn), c(Li), c(Ga), and c(V); ③ Obtain the discrimination factors F1, F2, and F3 Use 3*c(Sn)+c(Li) as the abscissa and c(Ga)*c(V) as the ordinate for plotting, obtain the dividing lines of different ore deposit types based on the plotting range, and obtain the discrimination factors F1 - F3, where: F1=0.001*(3*c(Sn)+c(Li)) 2.7 (Formula 1) F2=5*10 16 *(3*c(Sn)+c(Li)) -3.5 (Formula 2) F3=2*10 6 *(3*c(Sn)+c(Li)) -1.0 (Formula 3).

2. The method according to claim 1, characterized in that: In step 1), the criteria for distinguishing magmatic tourmaline from hydrothermal tourmaline are: magmatic tourmaline occurs in a disseminated form in weakly altered rock masses, while hydrothermal tourmaline occurs in veins or forms in strongly altered rocks.

3. The method according to claim 1, characterized in that In step 2), conduct in-situ microarea element analysis of laser ablation inductively coupled plasma mass spectrometry on the tourmaline samples, and the tested elements include Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, U.

4. The method according to claim 1, characterized in that: In step 2), use ICPMSDataCal software to process the test data to obtain data in the form of an Excel file.

5. The method according to claim 4, characterized in that During the test, it is possible that magmatic tourmaline may be detected or hit incorrectly. The following standards are used to eliminate the test data: B>10000ppm eliminates the wrong or through data; Ba<0.6ppm eliminates magmatic tourmaline; finally, the tourmaline trace data is obtained.

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