CAVE AND PALEOSOL MINERALOGY FROM ELEUTHERA, THE BAHAMAS

Cave minerals and paleosols on Eleuthera were sampled to determine their mineralogy. Paleosol samples were processed to remove carbonates and organics before fractionating by size. Treatments (K-saturation, Mg-Saturation, Heating, and Gylcolnation) were used to determine the specific clay mineralogy of each sample. Cave mineral samples were powdered and analyzed using powdered X-ray Diffraction (XRD).

The dominant clay mineral present in the paleosols present with Hatchet Bay Cave on Eleuthera was Fe-rich chlorite and Illite. Non-clay materials include low-Mg calcite and quartz. Cave minerals included carbonates (calcite and aragonite), sulfates (gypsum), phosphates (hydroxyapatite, fluorapatite, chlorapatite, and woodhouseite), and Mn-oxides. All minerals except woodhouseite have previously been reported from Bahamian caves. Woodhouseite formation represents phosphate-rich leachate derived from the combination of seawater and bat guano interacting with the various aluminum-rich phases found within the clay fraction of the paleosol exposed in Hatchet Bay cave. Previous Bahamian cave mineral studies did not sample exposed paleosols within caves, making this an interesting addition to the diverse cave mineral inventory of The Bahamas.