Red clayey soils, which were found to be highly phosphatic, overlie relatively pure limestone in the northern part of Bermuda. X-ray diffraction of the 0.2 to 0.5 mm sand fractions of two such soils revealed a mineralogy similar to that of volcanic impurities in one outcrop of limestone, in beach sand, and in submarine red clay from Castle Harbour. The occurrence of the distinctive red soils on these islands appears to have depended on weathering of restricted deposits of limestone that contained significant proportions of minerals derived from Pleistocene volcanic rocks. These impure deposits overlaid the relatively pure limestone. The phosphate in the soil appears to have been derived from guano.

First Page Preview

First page PDF preview
You do not currently have access to this article.