RT Journal Article
T1 Root calcret formation on Quaternary karstic surfaces of Grand Cayman.
A1 Alonso-Zarza, Ana María
A1 Bones, B.
AB The rugged karst terrain developed on the dolostones of the Miocene Cayman Formation (Fm) on Grand Caymanincludes numerous large cavities that formed through the activity of tree roots. The surfaces of those cavitiesare coated with laminated calcrete crusts up to 8 cm thick that are formed of an alteration zone, an accretionaryzone, and final infill of the cavities. These crusts are formed of various laminae, including dolostonewith root traces, alveolar septal structures, peloids, micritic and microsparitic laminae, micrite with bioclasts,and pisoliths. Features such as microborings, spores, needle-fiber calcite and micro-rods are common in allparts of the calcrete crust. Calcrete formation was initiated as the roots and associated microorganisms generatedthe cavities. Later on trapping and binding processes and organically induced precipitation of carbonateallowed the formation of the accretionary (mostly laminar) part of the calcrete. The last phases of crust formationtook place when ponded waters filled the cavities. The calcrete crusts developed on the Cayman Formationdolostones record a very specific setting for calcrete formation and constitute a good example of non-horizontalcalcrete crusts.
PB Instituto de Ciencias de la Tierra "Jaume Almera" (Barcelona)
SN 1695-6133
YR 2007
FD 2007
LK https://hdl.handle.net/20.500.14352/50431
UL https://hdl.handle.net/20.500.14352/50431
LA eng
DS Docta Complutense
RD 8 may 2024