GEOSCAN Search Results: Fastlink


TitleAn occurrence of cadmiferous phosphorite soil concretions in Jamaica
AuthorGarrett, R G; Porter, A R D; Hunt, P A
SourceApplied Geochemistry vol. 25, 2010 p. 1047-1055,
Alt SeriesEarth Sciences Sector, Contribution Series 20090426
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf
AreaManchester Parish; Jamaica
Lat/Long WENS-77.5000 -77.2500 18.1667 18.0000
Subjectssoils 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
Illustrationssketch maps; photomicrographs; geochemical analyses
AbstractBauxite 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.

Date modified: