Enigmatic Structures on Upper Pleistocene Laminar Caliche Surfaces of the Bahamas: Animal, Vegetable, or Mineral?
Proceedings of the 14th Symposium on the Geology of the Bahamas and Other Carbonate Regions
Trace fossils are a common and important component of most Quaternary carbonate rock units of the Bahamas and other, similar tropical carbonate regions. In the Bahamas, the Pleistocene-Holocene boundary is typically marked by a calichified paleosol horizon that formed on the exposed limestone surfaces of the islands during the time of lowered sea level of the Last Glacial. On the north coast of San Salvador Island, an extensive horizontal surface of laminar caliche is exposed at Singer Bar Point and to the west. This surface formed on carbonate eolianite of Late Pleistocene (Eemian) age and is overlain by Holocene eolianite. The surface bears numerous and distinctive large, meandering structures that typically are preserved in half relief, with sharp, parallel ridge-like edges that slope inward to form a smooth, medial 'trough.' Widths of these trough shaped structures mostly range between 1 to 3 cm, although some are wider, and individual structures commonly can be traced for lengths of several meters, with one specimen having a length of greater than 5m. Patterns formed by the structures can be quite complex and unusual, with crossovers common but branching only occasionally present.
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Curran, H. Allen, "Enigmatic Structures on Upper Pleistocene Laminar Caliche Surfaces of the Bahamas: Animal, Vegetable, or Mineral?" (2010). Geosciences: Faculty Publications, Smith College, Northampton, MA.
Reprinted with permission from: Frederick D. Sievers & Jonathan B. Martin (eds.), Proceedings of the 14th Symposium on the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Gerace Research Centre