## 1 Introduction
Generally, 11 kinds of fixed elements and indicator elements that can represent different characteristics are selected. The second step is to determine the reference value. According to the purpose of different genes, we select different data to standardize the data. For example, the element abundances of the upper continental crust (UCC) and acidic rocks and basic rocks compiled by [PERSON] and [PERSON] are selected for data standardization. The third step is to draw and code gene lines. The spectral line of the gene is like a spider map on the normalized value of the initial sequence. The length of the gene code is set to 11 because 11 elements are selected. The first digit of the code is set to 1, and then the next digit will be 0, 1, or 2 according to the decrease, stability, or rise of the next normalized value on the spectral line. We use the 0.1 logarithmic unit (base 10) value to evaluate the difference between two adjacent elements on the log-normalized value, marked as \(\Delta\), calculated as  
\[\Delta_{i}=\lg(C_{i})_{\mathrm{N}}-\lg(C_{i~{}-~{}1})_{\mathrm{N}} \tag{1}\]  
where \(i\) is the sequence number from 2 to 11 of the elements in the spectral line, and the subscript N represents the normalized value. In addition to the first number set to 1, another number in the code is labeled g\({}_{i}\) and set as  
\[\mathrm{g}_{i}=\left\{ \begin{array}{ll}2,&\Delta_{i}>0.1\\ 1,&-0.1\leq\Delta_{i}<0.1\\ 0,&\Delta_{i}<-0.1\end{array} \right. \tag{2}\]  
where \(i\) is from 2 to 11, and the value of g\({}_{i}\) in gene coding is only 0, 1, or 2. According to the coding method, the gene of one sample can be 11011020011, and the gene of the other sample can be 12210202120. How to evaluate the similarity between two genes is the fourth step in constructing geochemical genes. The similarity of g\({}_{i}\) is marked as \(R_{i}\) and set as  
\[R_{i}=\left\{ \begin{array}{rl}1,&\text{Values of g}_{i}\text{ are the same}\\ 0.5,&\text{Values of g}_{i}\text{ are similar (1 and 0, or 1 and 2)}\\ 0,&\text{Values of g}_{i}\text{ are different (2 and 0, or 0 and 2)}\end{array} \right. \tag{3}\]  
Then, the similarity between the two genes is labeled as \(R\) and calculated as  
\[R=\frac{\sum_{i=2}^{n}R_{\text{g}_{i}}}{n-1}\times 100\% \tag{4}\]  
where \(n\) is 11 and the value of \(R\) is limited between 0% and 100%. For example, the similarity between Gene A and Gene B is calculated as  
\[\text{Gene A: 1 1 0 1 1 0 2 0 0 1 1}\]  
\[\text{Gene B: 1 2 2 1 0 2 0 2 1 2 0}\]  
\[R_{\text{g}_{i}}\text{: 0.5 0 1 0.5 0 0 0 0.5 0.5 0.5}\]  
\[R=\frac{0.5+0+1+0.5+0+0+0.5+0.5+0.5}{10}\times 100\%=35\%\]  
The last step in constructing geochemical genes is to adjust the sequence of elements in the spectral lines. According to the different research objects of genes, the most obvious differentiation can be achieved by adjusting the sequence of elements. For example, the element sequence of the lithogene LG03 is to effectively distinguish acidic rock and basic rock to maximize their genetic similarity. By repeatedly adjusting the initial element sequence in step 3, the positions of Ni and Cr are exchanged, and then the positions of V and Cr are exchanged to form the final sequence. With respect to the lithogenes LG01 and LG03, the gene properties of their heredity and inheritance have been tested on many weathering profiles developed over different lithological rocks in different climate zones in China [26; 27; 32] according to the similar gene criterion of \(\geq\)80% on gene similarity by [PERSON] et al. (2018) [25]. Their application in classifying geological materials is useful and suitable for fresh and altered rocks and weathered products such as fresh rocks, sediments, and soils [20]. In this paper, TEM was used to observed the ores, fault muds, and soils in the Jiaojia gold deposit, Shandong Province.