The present invention relates to the technical field of ore prospecting in geological exploration, and in particular to a method for discriminating ore prospecting types based on compositional change of epidote.
With the comprehensive coverage of geological exploration in recent decades, the degree of mineral exploration has gradually increased, the discovery of new deposits has become increasingly difficult, and there is an urgent need to carry out new ore prospecting technical methods to guide the ore prospecting breakthrough, of which the primary task is to quickly discriminate the ore prospecting types.
The traditional discrimination of ore prospecting types has the following shortcomings: comprehensive research, such as large-scale mapping and systematic sampling analysis, is required before exploration and evaluation to clarify the orebody occurrence, the relationship with wall rocks, metallogenesis, ore-forming materials and ore-forming fluid sources, etc., so as to determine the genesis of deposits or ore prospecting types, resulting in long period and high cost, which cannot meet the urgent need for rapid exploration and evaluation at the ore concentration area scale.
To solve the technical problem above, the present invention provides a method for discriminating ore prospecting types based on compositional change of epidote. The method provided by the present invention has the advantages that the description of epidote altered minerals in a magma-hydrothermal metallogenic system is improved from macroscopic characterization to microscopic quantitative interpretation of trace element change in the epidote altered minerals by using an advanced LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry) in-situ analysis technology, and the trace element change is linked with the response of the ore prospecting type at an ore concentration area scale, thus overcoming the difficulties of low efficiency, long period and high cost in the traditional method for discriminating the ore prospecting types.
The present invention is achieved through the following technical solutions: a method for discriminating ore prospecting types based on compositional change of epidote specifically includes the following steps:
Through the technical solution above, geochemical characteristics of the epidote are introduced into the discrimination of ore prospecting types, which effectively makes up for the defect that there is no quantitative discrimination method at present, and the calculation method is more novel. Further, in step (5), the formula (1) is to perform logarithm transformation on the contents of La and Y elements in the epidote to obtain lg(V(La)) and lg(V(y)), to plot with lg(V(La)) as the abscissa and lg(V(Y)) as the ordinate, respectively, and to obtain a demarcation line between the porphyry type deposit and epithermal type deposit based on the plotting range.
Further in step (5), the formula (2) is to perform logarithm transformation on the contents of Gd, Yb, Sr and As elements in the epidote to obtain lg(V(Gd+Yb)) and lg(V(Sr/As)), to plot with lg(V(Gd+Yb)) as the abscissa and lg(V(Sr/As)) as the ordinate, respectively, and to obtain a demarcation line between the porphyry type deposit and epithermal type deposit based on the plotting range.
Further, step (2) includes the following steps: positioning each sample point by using a GPS positioning system, collecting coordinate data X and Y, taking field photos, and making detailed field records to describe lithology, alteration and mineralization characteristics of each sample.
Further, in step (4), the specific process is as follows:
Through the technical solution above, the influence of other auxiliary minerals on the calculation of the discriminant factors of trace elements in the epidote mineral can be eliminated, and the method may be suitable for the processing of trace element data of the epidote in different types of deposits.
Preferably, the research area is Zhunuo ore concentration area.
In addition, application of a method for discriminating ore prospecting types based on compositional change of epidote for the discrimination of an epithermal type Ag-Au deposit is provided. Quantitative indexes of trace elements in the epidote are as follows: calculating discriminant factors C1=0.28493059*lg(V(La))+0.5762992 and C2=lg(V(Gd+Yb))+ 1.5, respectively, according to the formula (1) and the formula (2); and when C1 is less than lg(V(Y)) and C2 is greater than lg(V(Sr+As)), discriminating that a deposit to which the epidote belongs is an epithermal type deposit.
Application of a method for discriminating ore prospecting types based on compositional change of epidote for the discrimination of a porphyry type Cu deposit is provided. Quantitative indexes of trace elements in the epidote are as follows: calculating discriminant factors C1=0.28493059*lg(V(La))+0.5762992 and C2=lg(V(Gd+Yb))+ 1.5, respectively, according to the formula (1) and the formula (2); and when C1 is greater than lg(V(Y)) and C2 is less than lg(V(Sr+As)), discriminating that a deposit to which the epidote belongs is a porphyry type deposit.
Through the technical solution above, the present invention belongs to a microscopic quantitative discrimination method, which is more scientific, reasonable and accurate in comparison with the traditional macroscopic qualitative discrimination method.
Compared with the prior art, the present invention has the advantages that:
(1) The description of epidote altered minerals in a magma-hydrothermal mineralization system is improved from macroscopic characterization to microscopic quantitative interpretation of trace element changes by using an advanced LA-ICP-MS in-situ analysis technology, and the trace element change is linked with the response of the ore prospecting types in an ore concentration area scale, which effectively makes up for the defect that there is no quantitative discrimination method at present, and overcomes the difficulties of low efficiency, long period and high cost in the traditional method for discriminating the ore prospecting types.
(2) It is proposed to use epidote as a characteristic mineral for discrimination, which has good connectivity and wide physical and chemical conditions, is sensitive to the changes of physical and chemical conditions, can be formed at high temperature, medium temperature and low temperature, is uniform in spatial distribution, develops in different alteration zones, and thus is more conducive to the distinction of different mineralization types.
(3) The characteristic elements, such as La, Y, Sr, As, Gd and Yb, in the epidote are sensitive to the changes of temperature, pH and redox conditions.
(4) An optimal discriminant factor is provided, which may be used for accurately distinguishing different types of deposits, and can provide a theoretical basis for the optimization and selection of further ore prospecting and exploration methods in the ore deposit scale and reduce the exploration risk.
The present invention is further described below with reference to the accompanying drawings.
A method for discriminating ore prospecting types based on compositional change of epidote specifically includes the following steps:
The specific steps are as follows:
On the basis of the above solution, step (2) includes the following steps: positioning each sample point by using a GPS positioning system, collecting coordinate data X and Y, taking field photos, and making detailed field records to describe lithology, alteration and mineralization characteristics of each sample.
On the basis of the above solution, preferably, the research area is the Zhunuo ore concentration area, specifically as follows:
The ore prospecting method provided by the present invention has the advantages of short test time, low cost, convenience and efficiency, environmental protection, and capability of effectively shortening the mineral exploration period without damaging the environment, greatly improving the accuracy of rapid discrimination and target prediction of the ore prospecting type at the ore concentration area scale and reducing the exploration risk, which is a new and indispensable exploration means and method, and has an important promotion and popularization value.
In addition, application of a method for discriminating ore prospecting types based on compositional change of epidote above for the discrimination of an epithermal type Ag-Au deposit is provided, where the contents of La, Y, Gd, Yb, Sr and As elements in the obtained epidote are defined as V(La), V(Y), V(Gd), V(Yb), V(Sr) and V(As), respectively.
(1) Calculation of a discriminant factor C1 is as follows:
performing logarithm transformation on the contents of La and Y elements in the obtained epidote to obtain lg(V(La)) and lg(V(y)), plotting with lg(V(La)) as the abscissa and lg(V(Y)) as the ordinate, respectively, obtaining a demarcation line between a porphyry type deposit and an epithermal type deposit based on the plotting range, and calculating the discriminant factor C1 by using the following formula:
(2) Calculation of a discriminant factor C2 is as follows:
performing logarithm transformation on the contents of Gd, Yb, Sr and As elements in the obtained epidote to obtain lg(V(Gd+Yb)) and lg(V(Sr/As)); plotting with the lg(V(Gd+Yb)) as the abscissa and the lg(V(Sr/As)) as the ordinate, obtaining a demarcation line between a porphyry type deposit and an epithermal type deposit based on the plotting range, and calculating the discriminant factor C2 by using the following formula:
(3) Discrimination of ore prospecting type is as follows:
substituting the content of La element in the obtained epidote into the formula above to calculate the discriminant factor C1, when C1 is less than lg(V(Y)) and C2 is greater than lg(V(Sr/As)), discriminating that a deposit to which the epidote belongs is the epithermal type deposit.
Application of a method for discriminating ore prospecting types based on compositional change of epidote above for the discrimination of a porphyry type Cu deposit is provided, where the contents of La, Y, Gd, Yb, Sr and As elements in the obtained epidote are defined as V(La), V(Y), V(Gd), V(Yb), V(Sr) and Y(As), respectively.
(1) Calculation of a discriminant factor C1 is as follows:
performing logarithm transformation on the contents of La and Y elements in the obtained epidote to obtain lg(V(La)) and lg(V(Y)), plotting with lg(V(La)) as the abscissa and lg(V(Y)) as the ordinate, respectively, obtaining a demarcation line between a porphyry type deposit and an epithermal type deposit based on the plotting range, and calculating the discriminant factor C1 by using the following formula:
(2) Calculation of a discriminant factor C2 is as follows:
performing logarithm transformation on the contents of Gd, Yb, Sr and As elements in the obtained epidote to obtain lg(V(Gd+Yb)) and lg(V(Sr/As)); plotting with the lg(V(Gd+Yb)) as the abscissa and the lg(V(Sr/As)) as the ordinate, obtaining a demarcation line between a porphyry type deposit and an epithermal type deposit based on the plotting range, and calculating the discriminant factor C2 by using the following formula:
(3) Discrimination of an ore prospecting type is as follows:
substituting the content of La element in the obtained epidote into the formula above to calculate the discriminant factor C1, when C1 is greater than lg(V(Y)) and C2 is less than lg(V(Sr/As)), discriminating that a deposit to which the epidote belongs is the porphyry type deposit.
The foregoing embodiments merely express one or several embodiments of the present invention, the description is relatively specific and detailed, but cannot be construed as a limitation to the scope of the present invention. It should be pointed out that those of ordinary skilled in the art can make several transformations and improvements without departing from the concept of the present invention, which all belong to the scope of protection of the present invention.
Number | Date | Country | Kind |
---|---|---|---|
202210273006.0 | Mar 2022 | CN | national |