Table 1.
The F, ca and mg levels in soils and rocks (mg/kg).
| Stratum | Lithology | Non-farmland area | Farmland area | Bedrock | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Surface soil | Soil in the mineral horizon | Surface soil | |||||||||||
| F | Ca | Mg | F | Ca | Mg | F | Ca | Mg | F | Ca | Mg | ||
| Baota Formation of the Mid-Ordovician (O2b) | Silty limestone | 595.72 | 63,693 | 8490 | 699.55 | 11,492 | 9751 | 468.77 | 28,555 | 9096 | 79.05 | 137,547 | 1785 |
| Wufeng Formation of the Late-Ordovician (O3w) | Argillaceous limestone | 880.44 | 5641 | 12,514 | 1419.28 | 14,083 | 12,933 | 1303.11 | 2462 | 10,634 | 131.45 | 291,528 | 3611 |
| Maokou Formation of the Early-Permian (P1m) | Bioclastic limestone | 585.94 | 6599 | 8373 | 682.37 | 8448 | 10,881 | 322.46 | 12,398 | 14,749 | 74.25 | 258,746 | 2467 |
| Emeishan Formation of the Mid-Permian (P2β) | Basalt | 567.04 | 2300 | 2134 | 476.34 | 8492 | 8858 | 481.4 | 3225 | 2662 | 964.11 | 54,474 | 18,618 |
| Longtan Formation of the Mid-Permian (P2l) | Shale | 433.95 | 823 | 6591 | 480.2 | 2147 | 8232 | 399.7 | 6914 | 16,807 | 648.34 | 1551 | 8425 |
| Changxing Formation of the Mid-Permian (P2c) | Limestone interbedded with shale | 936.09 | 6773 | 12,180 | 1278.01 | 5830 | 12,897 | 1216.95 | 4647 | 18,102 | 121.89 | 192,235 | 3547 |
| Feixianguan Formation of the Early-Trias (T1f) | Siltstone | 157.9 | 1678 | 13,844 | 334.58 | 7334 | 3718 | 227.52 | 5122 | 11,339 | 744.28 | 25,094 | 27,091 |
| Guanling Formation of the Mid-Trias (T2g) | Dolomite | 1076.76 | 2891 | 15,967 | 709.4 | 7372 | 8969 | 880.27 | 2668 | 13,217 | 46.05 | 215,647 | 4382 |
| Xujiahe Formation of the Late-Trias (T3x) | Siltstone and sandstone | 548.5 | 1722 | 10,932 | 465.47 | 4668 | 9125 | 527.81 | 393 | 5103 | 223.44 | 4601 | 5473 |