Action at the Geosphere-Biosphere Interface: New Messages from Cyanobacteria and Stromatolites
THURSDAY, NOVEMBER 10, 2011 - 3:30 PM TO 4:30 PM IN EIT 3142 AT THE UNIVERSITY OF WATERLOO
Abstract:
Laminated structures in the rock record constitute some of the oldest evidence for life on Earth, but the processes involved in the formation of stromatolitic lamination are still poorly understood. In this study, we investigated modern stromatolitic structures, which are growing in a hypersaline coastal lagoon, Lagoa Vermelha, Brazil. To determine if a metabolic signal is possibly preserved in the Lagoa Vermelha stromatolites, we have applied a high spatial resolution approach to characterize the organic matter enclosed in the carbonate laminae. Analytical transmission electron microcopy, plus electron energy loss spectroscopy (TEM-EELS), X-ray microscopy and scanning electron and laser microscopic studies were used to gain information about the biomineralization processes and associated metabolic mechanisms, such as photosynthesis, aerobic and anaerobic respiration, methanogenesis and fermentation.