## 3 Results
### Geochemistry of Altered Rocks  
The results of the geochemical test are shown in Table 1. During the process of rock alteration in the study area, accompanied by changes in the mineral composition and geochemical characteristics, the contents of the primary major rock elements have also changed. Compared with fresh rocks, the overall trend of the contents of TiO\({}_{2}\) (0.11-0.71%), Na\({}_{2}\)O (1.78-5.20%), and K\({}_{2}\)O (2.06-4.36%) in the altered granite is that of reduction. Compared with previous studies [39; 40; 41; 42; 43; 44; 45], the contents of MgO (0.18-2.86%) and CaO (0.54-10.75) in the samples obtained in this study are more anomalous with the change of LOI, mostly showing a trend of increase with increasing LOI. This phenomenon reflects the continuous intrusion of carbonates with groundwater into strongly altered granites with pore development. Some granites exhibit evidence of cataclastic rockization. The maximum LOI (4.77-9.23%) of the cataclastic lithified granodiorite indicates a high degree of alteration of this rock type. The LOI of the cataclastic monzonitic granite is broadly consistent with that of other samples (0.59-4.15%). Meanwhile, the mineral particle size of the granodiorite might be related to the degree of alteration. Compared with the fine-grained and cataclastic granodiorite, the medium-grained granodiorite shows a smaller LOI, which is closer to that of fresh rock, indicating a lower degree of alteration. No significant correlation was observed between the LOI and the mineral particle size of the monzonitic granite samples.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Sample** & **Rock** & **SiO\({}_{2}\)** & **TiO\({}_{2}\)** & **Al\({}_{2}\)O\({}_{3}\)** & **TF\({}_{2}\)O\({}_{3}\)** & **MgO** & **CaO** & **Na\({}_{2}\)O** & **K\({}_{2}\)O** & **LOI** & \(\delta^{18}\)O** \\
**Number** & **Character** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **Mass\%** & **\%** \\ \hline
1 & Fresh-Bio- & & 70.68 & 0.27 & 15.41 & 1.92 & 0.65 & 2.59 & 3.7 & 3.58 & 0.74 & 8.6 \\
2 & & 67.58 & 0.47 & 13.60 & 2.94 & 1.58 & 3.30 & 3.20 & 3.13 & 3.51 & 11.4 \\
3 & & 80.97 & 0.25 & 7.66 & 1.63 & 0.67 & 2.20 & 2.20 & 2.06 & 2.06 & 2.7 \\
4 & & 72.64 & 0.46 & 12.11 & 2.85 & 1.32 & 1.76 & 3.29 & 3.05 & 2.17 & 2.7 \\
5 & & 75.11 & 0.47 & 11.07 & 2.87 & 1.21 & 1.21 & 2.57 & 3.32 & 1.49 & 2.6 \\
6 & & 69.85 & 0.52 & 13.97 & 3.11 & 1.13 & 2.56 & 3.24 & 3.70 & 1.38 & 11.1 \\
7 & & 66.37 & 0.50 & 14.05 & 3.04 & 1.26 & 4.04 & 3.50 & 3.26 & 3.82 & 11.3 \\
8 & & 70.93 & 0.47 & 13.61 & 3.05 & 1.32 & 2.26 & 3.58 & 3.08 & 1.40 & 6.2 \\
9 & & 64.74 & 0.52 & 14.44 & 3.17 & 1.32 & 4.22 & 3.30 & 3.44 & 4.15 & 11 \\
10 & & 66.85 & 0.51 & 13.45 & 3.12 & 1.24 & 3.66 & 3.98 & 3.42 & 3.39 & 11.5 \\
11 & & 70.47 & 0.54 & 13.54 & 3.43 & 1.39 & 2.80 & 3.47 & 2.98 & 0.60 & 9.3 \\
12 & & 68.98 & 0.58 & 13.75 & 3.60 & 1.45 & 2.32 & 3.94 & 2.93 & 2.01 & 5.1 \\
13 & & 68.97 & 0.61 & 13.66 & 3.79 & 1.54 & 2.54 & 3.57 & 3.13 & 2.33 & 5.2 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Contents of the major elements, and the LOI and \(\delta^{18}\)O values of the sample rocks.