Geochemical Mass Balance and Elemental Transport during the Weathering of the Black Shale of Shuijingtuo Formation in Northeast Chongqing, China

Table 3

Correlations among major elements, density, and pH value with principal components.

	Profile A				Profile B				Profile C
	PC1	PC2	PC3	PC4	PC1	PC2	PC3	PC4	PC1	PC2	PC3	PC4
SiO2	−0.967	0.137	−0.193	0.077	−0.892	−0.345	−0.050	−0.265	−0.921	0.378	−0.042	−0.037
Al2O3	−0.989	0.051	0.080	0.101	0.862	−0.253	0.384	0.079	−0.983	−0.078	0.091	−0.126
Fe2O3	0.525	−0.771	0.282	−0.195	0.569	−0.716	0.098	0.145	−0.003	−0.942	0.227	0.026
K2O	−0.955	0.160	0.193	0.082	0.906	−0.223	0.232	0.102	−0.984	−0.108	−0.014	−0.105
Na2O	−0.946	0.206	0.095	0.119	0.833	−0.095	0.015	−0.470	−0.618	0.529	0.439	0.367
CaO	0.945	0.171	−0.220	0.068	0.198	0.893	0.047	0.102	0.952	0.263	0.069	−0.010
MgO	0.878	0.128	0.238	0.371	0.806	0.403	0.280	0.222	0.813	0.283	0.322	−0.349
P2O5	0.265	−0.899	−0.010	0.203	−0.629	0.177	0.533	0.340	0.857	0.240	−0.346	0.144
SO3	0.872	0.385	0.040	−0.140	0.907	−0.083	−0.163	−0.042	0.345	−0.914	−0.064	0.152
LOI	0.852	0.495	0.100	−0.041	0.332	0.315	−0.731	0.472	0.968	−0.203	0.091	−0.001
ρ	0.883	0.397	0.146	0.068	0.588	0.635	−0.165	−0.382	0.941	−0.086	0.252	0.065
pH	0.864	−0.242	−0.266	0.139	−0.216	0.899	0.306	−0.156	0.490	0.808	−0.051	0.043
Eigen value	8.741	2.146	0.378	0.303	5.787	3.062	1.260	0.899	7.651	3.073	0.560	0.335
Variance explained (%)	72.840	17.882	3.154	2.524	48.222	25.518	10.503	7.489	63.758	25.605	4.670	2.795
Cumulative variance (%)	72.840	90.721	93.875	96.400	48.222	73.740	84.243	91.731	63.758	89.363	94.033	96.828