## 5 Application
### Application on Stream Sediments and Soils
\begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline
**Parameters** & **SiO\({}_{2}\)** & **Al\({}_{2}\)O\({}_{3}\)** & **Tree\({}_{2}\)O\({}_{3}\)** & **CaO** & **MgO** & **K\({}_{2}\)O** & **Na\({}_{2}\)O** & **TiO\({}_{2}\)** & **P\({}_{2}\)O\({}_{5}\)** & **CaO/MgO** & **WIG** \\ \hline Minimum value & 26.12 & 1.20 & 0.39 & 0.01 & 0.04 & 0.21 & 0.05 & 0.06 & 0.01 & 0.02 & 2.87 \\ Lower quartile value & 61.57 & 10.40 & 3.55 & 0.56 & 0.94 & 1.73 & 0.63 & 0.57 & 0.16 & 0.49 & 31.15 \\ Median value & 65.87 & 12.82 & 4.59 & 1.02 & 1.51 & 2.21 & 1.00 & 0.67 & 0.22 & 0.74 & 40.62 \\ Upper quartile value & 71.73 & 14.13 & 5.41 & 1.98 & 2.04 & 2.60 & 1.45 & 0.75 & 0.29 & 1.24 & 52.09 \\ Maximum value & 94.70 & 22.03 & 18.53 & 23.97 & 12.95 & 6.30 & 48.00 & 4.59 & 2.14 & 20.44 & 905.43 \\ Mean value & 67.13 & 12.02 & 4.51 & 1.64 & 1.54 & 2.17 & 1.10 & 0.70 & 0.23 & 0.97 & 43.98 \\ Standard deviation value & 8.34 & 2.88 & 1.66 & 1.75 & 0.82 & 0.60 & 0.82 & 0.34 & 0.11 & 0.79 & 26.34 \\ \hline \hline \end{tabular} Note: The unit of major oxide is %.  
\end{table} 
Table 4: Statistical parameters of stream sediment and soil samples in the southern Sichuan area. Figure 5: Geochemical map of the classified results on compositional data of stream sediments and soils in the southern Sichuan area. The main lithologies of the Quaternary stratum are gravel, grit, sand, and clay, which are determined as mostly type 2 and a small amount of type 1 and type 3. That is, the Quaternary stratum comprises mainly felsic components and a small amount of siliceous and silicate components. The Cretaceous stratum is composed mostly of the siliceous component (type 1) with a little of the felsic component (type 2), which is consistent with its lithology, including lithic sandstone, fine-silt sandstone, and mudstone. The main lithologies of the Jurassic strata are conglomerate, sandstone, siltstone, mudstone, and a small amount of limestone and marl. Most of them are classified as type 3 (silicate component). However, the components of the Jurassic strata in the eastern area belong to the felsic component (type 2), which may be mixed with the Cretaceous stratum of siliceous components in type 1, or the Upper Triassic stratum (T\({}_{3}\)) of felsic components in type 2, as discussed below. The main lithology of the Upper Triassic stratum (T\({}_{3}\)) is feldspar quartz sandstone intercalated with siltstone, which is classified as a felsic component (type 2). The main lithology of the Lower-Middle Triassic stratum (T\({}_{1-2}\)) is conglomerate, sandstone, shale, mudstone, limestone, and dolomite, which is determined as silicate components (type 3). The Permian stratum is mainly sand shale, limestone, dolomite, basalt, and mudstone, and most of them are classified as silicate components (type 3). This component is similar to that of the Lower-Middle Triassic stratum (T\({}_{1-2}\)). The Cambrian stratum in the western area comprises mainly shale, siltstone, sandstone, limestone, and dolomite. Most of them are classified as calcsilicate components (type 4), and few as silicate components (type 3). In addition, only two samples (each corresponding ca. 4 km\({}^{2}\)) in the western area are recognized as calcareous components (type 6) and dolomitic components (type 5), respectively. According to the above discussion on the relationship between the geochemical components and their lithology on different strata, we can derive that the older strata are different from their overlaying strata in terms of geochemical components in the southern Sichuan area, apart from the strata ranging from the Permian to the Lower-Middle Triassic strata. Compared with the differences in the lithological description of the strata in this area, the classified geochemical components are clearly illustrated in different numbers with different colors. Therefore, the new proposed method of geochemical classification of shale is also applicable to stream sediments and soils, and will play an important role in environmental and exploration geochemistry.