Title | An occurrence of cadmiferous phosphorite soil concretions in Jamaica |
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Author | Garrett, R G; Porter, A R D; Hunt, P A |
Source | Applied Geochemistry vol. 25, 2010 p. 1047-1055, https://doi.org/10.1016/j.apgeochem.2010.04.010 |
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Year | 2010 |
Alt Series | Earth Sciences Sector, Contribution Series 20090426 |
Publisher | Elsevier BV |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf |
Area | Manchester Parish; Jamaica |
Lat/Long WENS | -77.5000 -77.2500 18.1667 18.0000 |
Subjects | soils science; mineralogy; Oligocene; concretions; bauxite; phosphate; phosphates; phosphorites; zinc; cadmium; silver; beryllium; uranium; weathering; geochemical analyses; Miocene; Pliocene;
Walderston-Brown's Town Formation; White Limestone Supergroup; Tertiary |
Illustrations | sketch maps; photomicrographs; geochemical analyses |
Abstract | Bauxite exploration drilling revealed the presence of phosphate minerals through the chemical and XRD analysis of recovered drill hole samples at Spitzbergen, in Manchester Parish, Jamaica. A subsequent
pit led to the discovery of phosphorite concretions composed of hard competent masses of finely crystalline fluorapatite, with some minor crandallite. The phosphorite contains anomalously high levels of Zn (>5000 mg kg\'021), Cd (>1.1%), Ag (>20 mg
kg\'021), Be (>80 mg kg\'021) and, to a lesser extent, U. Textural and geochemical evidence indicates that the phosphorite concretions were most likely formed by the replacement of limestone by secondary deposition proximal to fossil guano deposits,
postulated to be Late Miocene or Pliocene sea-bird colonies. Mechanical dispersion of the phosphorite concretions through karst weathering processes has led to their wider spatial distribution than the original guano deposits. Subsequent weathering
of the concretions and the admixture of their decomposition products into the bauxitic and Terra Rossa soils is postulated to be the cause of the widespread anomalous levels of Zn, Cd and Be in these soils in central Jamaica, and the elevated levels
of P in the bauxite. |
GEOSCAN ID | 261751 |
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