Genesis, Mineralogy and Related Properties of West Indian Soils: I. Bauxitic Soils of Jamaica
1966
Ahmad, N. | Jones, Robert L. | Beavers, A. H.
The red and brown bauxite soils of Jamaica occurring over hard, pure white limestone are strongly aggregated, freely drained soils of almost pure clay texture. They are of low fertility, nitrogen and potassium being very deficient. The red bauxite is deficient in available phosphate but not responsive to phosphorus fertilization. Phosphorus fractionation data show both soils to be adequately supplied with phosphorus. The brown bauxite is much higher than the red in total phosphate and in aluminum- and calcium-bonded forms. Both soils are very high in iron-bonded phosphate with the red bauxite having a greater percentage of the total phosphate in reductant soluble form. Chemical analysis shows the soils to be very high in Al₂O₃ content with little or no difference between the two soils. Silica content is very low. Iron is high and virtually all of it is present in dithionite extractable form. No minerals containing potassium seem to be present in the soils. Mineralogical study shows the Al₂O₃ to be present as gibbsite and boehmite in a ratio of 2:1 for both soils. The soils had less than 10% kaolinite, the brown bauxite being higher. Traces of chlorite were identified in both soils, and traces of montmorillonite were found in the deeper layers of the brown bauxite. Titanium was present as rutile and anatase in the brown bauxite but only as anatase in the red. The red bauxite is richer in goethite. The low content of silicates in the bauxites is associated with a low SiO₂ content of the insoluble residue of the limestone and this is evidence for possible genesis of the bauxites from the underlying limestone.
显示更多 [+] 显示较少 [-]