Table 1 Major element contents of surface sediments in Lake Qinghai
From: Spatial and temporal variations of Rb/Sr ratios of the bulk surface sediments in Lake Qinghai
| Â | Â | Surface sediments in Lake Qinghai | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Â | Â | QH0710 | STS | QH0708 | QH0706 | QH0707 | QH0711 | QH0709 | #1 |
SiO2(%) | Mixed-core | 48.8 | 50.8 | 43.0 | 39.9 | 38.6 | 38.0 | 37.4 | 36.7 |
| Â | 1963-sect. | 48.2 | 48.6 | 41.4 | 39.9 | 40.8 | 38.6 | 35.6 | 36.8 |
Al 2 O 3 (%) | Mixed-core | 11.4 | 9.9 | 9.6 | 10.1 | 9.5 | 9.7 | 9.0 | 9.5 |
| Â | 1963-sect . | 10.6 | 10.3 | 9.3 | 9.3 | 9.6 | 8.9 | 8.5 | 9.4 |
Fe2O3(%) | Mixed-core | 4.6 | 4.2 | 4.1 | 4.1 | 3.9 | 3.9 | 3.7 | 3.8 |
| Â | 1963-sect. | 4.2 | 4.3 | 4.1 | 4.0 | 4.1 | 3.8 | 3.5 | 3.6 |
MgO(%) | Mixed-core | 4.0 | 4.5 | 4.1 | 3.8 | 3.5 | 3.6 | 3.7 | 3.4 |
| Â | 1963-sect . | 3.8 | 4.1 | 4.2 | 4.4 | 4.1 | 4.2 | 3.9 | 3.6 |
CaO(%) | Mixed-core | 12.3 | 10.7 | 16.3 | 18.6 | 19.2 | 20.5 | 21.3 | 21.7 |
| Â | 1963-sect. | 12.9 | 12.6 | 17.2 | 17.8 | 16.8 | 19.9 | 22.6 | 21.8 |
Na 2 O(%) | Mixed-core | 2.1 | 2.1 | 2.5 | 2.4 | 2.3 | 2.7 | 2.3 | 2.5 |
| Â | 1963-sect . | 2.3 | 2.4 | 2.6 | 2.8 | 3.1 | 2.7 | 2.6 | 2.7 |
K2O(%) | Mixed-core | 2.5 | 2.1 | 2.1 | 2.2 | 2.1 | 2.1 | 2.0 | 2.1 |
| Â | 1963-sect. | 2.3 | 2.2 | 2.0 | 2.1 | 2.1 | 2.0 | 1.9 | 2.1 |
Ti(ppm) | Mixed-core | 3498.1 | 3472.5 | 3145.8 | 2960.5 | 2741.8 | 2814.4 | 2755.1 | 2720.8 |
| Â | 1963-sect . | 3342.6 | 3455.2 | 3062.7 | 2906.8 | 2975.0 | 2797.7 | 2544.0 | 2677.4 |
Rb(ppm) | Mixed-core | 102.4 | 98.0 | 104.3 | 112.5 | 113.1 | 100.5 | 95.7 | 101.3 |
| Â | 1963-sect. | 97.9 | 98.0 | 103.4 | 129.9 | 117.4 | 116.2 | 94.8 | 92.5 |
Sr(ppm) | Mixed-core | 354.7 | 400.0 | 618.0 | 726.1 | 805.3 | 772.1 | 832.4 | 869.0 |
| Â | 1963-sect . | 385.3 | 449.5 | 662.6 | 700.4 | 648.6 | 782.8 | 920.9 | 824.1 |