Elemental analysis of the geothermic microecology of the Los Azufres (Mexico) volcanic complex

Three geothermal microecologies, constituted of fumaroles, hydrothermal springs and the native volcanic superstratum at the Los Azufres (Mexico) volcanic complex, have been analysed for the concentrations of Cd, Hg, Pb, Th and U in the tissues and rhizospheric soils of the extremophilic plants that colonise the fumaroles, as well as in the sediments and volcanic stratum, using Polarised Energy Dispersive X-ray Fluorescence spectrometry and supplementarily, by Inductively Coupled Plasma Mass Spectrometry and Neutron Activation Analysis. The plants are found to sequester high concentrations of these heavy elements in their tissues and are more effective at their immobilization in the rhizosphere than are the hydrothermal chemistries for the sediment. Inferences are drawn regarding their roles in, in the biogeochemical recycling of these heavy elements in the Paleozoic era whose ecology these geothermal niches 'mimic', as well as their potential for phytoremediation. (author)