This application claims priority to Chinese Patent Application No. 202310824618.9 with a filing date of Feb. 23, 2023. The content of the aforementioned application, including any intervening amendments thereto, is incorporated herein by reference.
The present invention belongs to the field of deposit exploration and evaluation, and in particular relates to a method for discriminating deposit types by using tourmaline components.
Porphyry deposits refer to fine-mesh veined and disseminated ore bodies widely distributed in and around porphyry-like rocks. The porphyry deposit plays an extremely important role in the world's deposit types, and currently porphyry copper deposits supply nearly 75% of copper, 50% of molybdenum and 20% of gold in the world. The porphyry deposits in China include porphyry-type Cu (—Mo, —Au), porphyry-type Mo, porphyry-type Au, and porphyry-type Pb—Zn. Sn and W are important strategic minerals in China, and granite-related Sn—W deposits are the main source of Sn and W. Iron oxide-copper-gold (IOCG) deposits are an important deposit type proposed in recent 20 years. This type of deposit has large reserves, contains a large amount of low-Ti-content iron oxides, and is accompanied by Cu and Au with great economic values, and enriches metals such as REE, U, P and Co to varying degrees, and thus the IOCG deposit has significant scientific research values and exploration significance.
Currently, traditional determination of deposit types primarily relies on geochemical survey of rock, large-scale lithology-alteration-mineralization mapping, borehole verification, etc. However, these methods require a large amount of manpower and money, have a long period, and high costs, and cannot meet the urgent need for rapid exploration and evaluation.
Therefore, there is a need to find an accurate, economical, and efficient method to discriminate deposit types.
An object of the present invention is to provide a method for quickly discriminating deposit types by using tourmaline components, which realizes quick discrimination of the deposit types during prospecting and exploration, shortens the exploration period, and reduces the exploration cost, and the method can be used for identification of 4 different types of deposits, and is a new method for prospecting that is economical, efficient, and green.
In order to achieve the above object, the present invention adopts the following technical solutions:
According to the above solution, in the step 1), a criterion for distinguishing the magmatic tourmaline from the hydrothermal tourmaline is as follows: the magmatic tourmaline is produced in a disseminated form in a weakly altered rock mass while the hydrothermal tourmaline is produced in a veined form or formed in strongly altered rock.
According to the above solution, in the step 2), the in-situ micro-area elemental analysis by laser ablation inductively coupled plasma mass spectrometry is performed on the tourmaline samples, and analytical elements include Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, B, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, and U.
According to the above solution, in the step 2), analytical data is processed by using ICPMSDataCal software to obtain data in an Excel format file.
Preferably, there may be mistake data existing in the analytical data, and the analytical data is processed by rejecting the mistaken data according to the following criteria: when a content of B element c(B)>10000 ppm which indicates that a test location on the sample is wrong or the probe sheet is penetrated, rejecting the mistaken data; and when a content of Ba element c(Ba)<0.6 ppm which indicates that the probe sheet is the magmatic tourmaline, rejecting the mistaken data.
The principle of action of the method of the present invention is as follows:
The beneficial effects of the present invention are as follows:
In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
Specific steps of obtaining discriminant factors F1, F2, and F3 are as follows:
First, tourmalines are identified in a porphyry type Cu—Mo deposit, a porphyry type Au deposit, a granite-related Sn—W deposit and an IOCG type Au deposit, respectively. Secondly, magmatic tourmaline is distinguished from hydrothermal tourmaline, and specific manifestation features are as follows: the magmatic tourmaline is produced in a disseminated form in weakly altered rocks while the hydrothermal tourmaline is produced in a veined form or formed in strongly altered rocks. Finally, samples containing hydrothermal tourmaline are collected.
The samples containing tourmalines are prepared into probe sheets, and tourmalines are identified under a microscope, and are marked by using a marker pen. Tourmalines with a well-developed crystal form and larger particles satisfying the analytical conditions are selected for in-situ micro-area elemental analysis by laser ablation inductively coupled plasma mass spectrometry. Analytical elements include Li, Be, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sn, Sb, B, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th, and U.
The analytical data is processed by using ICPMSDataCal software to obtain data in an Excel format file. Further, it is possible to perform mistaken penetration or detect magmatic tourmaline during analysis, and the analytical data is rejected by using the following criteria: when B>10000 ppm, mistaken penetration or penetration data is rejected; and when Ba<0.6 ppm, the magmatic tourmaline is rejected, finally obtaining trace element data of tourmaline.
The data obtained in the step (3) is processed by using Excel. Analysis of Sn, Li, Ga, and V trace elements in the turmaline is performed. The contents of the trace elements Sn, Li, Ga, and V in the turmaline are defined as c(Sn), c(Li), c(Ga), and c(V).
Diagram projection is performed with 3*c(Sn)+c(Li) as an abscissa and c(Ga)*c(V) as an ordinate, as shown in
The contents of Sn, Li, Ga, and V trace elements in the hydrothermal tourmaline to be analyzed are obtained according to the method in the steps (1) and (2), denoted as c(Sn), c(Li), c(Ga), and c(V); and the Sn content and the Li content are substituted into the formula 1, the formula 2 and the formula 3 to calculate the discriminant factors F1, F2 and F3, respectively; wherein:
and
Discrimination of a deposit type by using tourmaline components: taking a porphyry Cu—Mo deposit in Beimulang, Tibet as an example, the specific steps are as follows:
It should be understood that for those of ordinary skill in the art, modifications and variations can be made according to the above descriptions, and all these modifications and variations should fall within the scope of protection of the appended claims.
Number | Date | Country | Kind |
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202310824618.9 | Jul 2023 | CN | national |