# Temporal Variations of Sediment Provenance in a Karst Watershed, China
## 3 Results
### Sediment Provenance Process  
From the geological background of the study area, four major sources (limestone, dolomite, sand-shale and mudstone, and lead-zinc tailings) were identified as possible contributors of catchment sediments. Based on the elements/oxides identified in the sources, and those measured in all three baseline projects, 28 geochemical indexes were selected as tracers, namely: Al\({}_{2}\)O\({}_{3}\), B, Ba, Be, CaO, Ce, Co, Cr, Cu, Fe\({}_{2}\)O\({}_{3}\), Ga, La, Li, MgO, Mn, Mo, Nb, Ni, P, Rb, S, SiO\({}_{2}\), Th, Ti, U, V, Y, and Zr. Through a series of evaluations described in Section 2.2, 16 elements (Al, B, Be, Co, Ga, La, Li, Mo, Nb, Ni, Si, Th, U, V, Y, Zr) were identified as conservative tracers. The mean contents of geochemical tracers in the four major sources (limestone, dolomite, sand-shale and mudstone, and lead-zinc tailings) are shown in Figure 3. The average element concentration characteristics of tracers in the lead-zinc tailings (shown in green line) were significantly different from others, while the limestone, dolomite, and sand-shale and mudstone as background lithologies exhibited relatively similar tracer variations trends, with some obvious differences in typical element contents. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & & **As** & **Cd** & **Cr** & **Cu** & **Hg** & **Ni** & **Pb** & **Zn** \\ \hline \multirow{6}{*}{**C**} & \multirow{3}{*}{Soil} & Min & 10.26 & 0.036 & 48.8 & 5.7 & 40.2 & 6.7 & 10.5 & 21.9 \\  & & Median & 27.17 & 0.902 & 101.5 & 16.4 & 174.0 & 31.7 & 39.0 & 75.1 \\  & & Max & 16.66 & 0.151 & 63.9 & 9.9 & 81.4 & 12.1 & 20.0 & 51.9 \\ \cline{2-11}  & & CV & 33.2 & 108.8 & 26.7 & 31.3 & 46.7 & 54.3 & 45.5 & 41.6 \\ \cline{2-11}  & \multirow{3}{*}{Rock} & Min & 0.57 & 0.036 & 3.0 & 6.8 & 14.9 & 4.4 & 2.3 & 18.7 \\  & & Median & 11.00 & 0.279 & 48.6 & 12.6 & 33.7 & 12.7 & 21.2 & 34.4 \\ \cline{2-11}  & & Max & 24.39 & 1.267 & 57.0 & 19.3 & 104.0 & 32.4 & 96.2 & 208.0 \\ \hline \multirow{6}{*}{**C**} & \multirow{3}{*}{Soil} & \multirow{3}{*}{Min} & 4.10 & 0.011 & 31.0 & 5.5 & 36.3 & 5.0 & 7.9 & 20.5 \\  & & Median & 4.64 & 0.026 & 43.5 & 6.6 & 43.6 & 5.6 & 10.6 & 22.4 \\  & & Max & 6.41 & 0.064 & 55.9 & 9.8 & 61.2 & 7.4 & 12.7 & 27.2 \\ \cline{2-11}  & & CV & 21.2 & 76.9 & 23.4 & 26.1 & 22.9 & 17.7 & 23.2 & 12.4 \\ \cline{2-11}  & \multirow{3}{*}{Rock} & Min & 1.46 & 0.028 & 17.0 & 6.7 & 16.1 & 2.8 & 4.4 & 12.5 \\  & & Median & 2.50 & 0.037 & 47.7 & 8.3 & 20.6 & 8.8 & 15.7 & 20.3 \\ \cline{2-11}  & & Max & 3.57 & 0.070 & 57.6 & 9.7 & 43.3 & 13.8 & 26.1 & 27.3 \\ \hline \multirow{6}{*}{**C**} & \multirow{3}{*}{Soil} & \multirow{3}{*}{Min} & 5V & 34.9 & 45.6 & 43.0 & 14.9 & 48.9 & 53.4 & 59.9 & 35.8 \\ \cline{2-11}  & & & Min & 9.54 & 0.036 & 36.4 & 7.9 & 59.4 & 5.7 & 13.4 & 17.5 \\ \cline{2-11}  & & Median & 19.57 & 0.101 & 58.2 & 10.1 & 88.3 & 7.4 & 20.8 & 59.9 \\ \cline{2-11}  & & Max & 44.06 & 0.827 & 110.2 & 21.9 & 124.1 & 55.9 & 32.5 & 104.9 \\ \cline{2-11}  & & CV & 50.1 & 122.9 & 39.9 & 41.8 & 27.4 & 92.7 & 30.0 & 65.1 \\ \cline{2-11}  & \multirow{3}{*}{Rock} & Min & 14.10 & 0.080 & 35.9 & 9.5 & 26.0 & 6.5 & 13.1 & 23.3 \\ \cline{2-11}  & & Median & 19.87 & 0.311 & 64.8 & 14.9 & 62.8 & 25.3 & 22.7 & 68.9 \\ \cline{2-11}  & & Max & 50.20 & 0.349 & 88.8 & 20.1 & 106.5 & 39.3 & 39.7 & 93.7 \\ \hline \multirow{6}{*}{**C**} & \multirow{3}{*}{Soil} & \multirow{3}{*}{Min} & 5V & 56.6 & 49.0 & 31.8 & 29.5 & 40.5 & 62.7 & 39.2 & 44.7 \\ \cline{2-11}  & & & & & & & & & & \\ \cline{1-1} \cline{2-11}  & & Content & 1485 & 27.69 & 48.2 & 144.4 & 342.6 & 30.6 & 1168 & 1890.0 \\ \hline \hline \end{tabular}  
Unit: mg/kg; CV: Coefficient of variation.  
\end{table} 
Table 2: Statistical parameters of toxic metals. The selected tracers exhibited an identification accuracy of 100% by testing the SIFT for accuracy using virtual mixing samples (step 4 as described in 2.2), so the geochemical tracers were used for sediment provenance.