Currently Funded Projects

NSF-EAR Geobiology and Low-temperature Geochemistry

"Assessing the role of methanogens in driving earth oxygenation using Ni isotopes."

For this project we are measuring Ni isotope compositions of banded iron formation samples of all ages. Our aim is to determine whether these rocks record a shift in the biogeochemical cycle of Ni that may have been caused by a precipitous drop in seawater Ni concentrations just prior to the Great Oxidation Event (Konhauser et al., 2009, Nature 458:750.) Such a shift may represent the onset of enzymatic Ni limitation of methanogens, the organisms that likely sustained the Earth’s anoxic atmosphere for over a billion years.

NASA Exobiology

"Investigating the role of methanogens in the Great Oxidation Event using Ni isotopes."

This grant supports experimental work that complements the NSF-EAR project described above, by aiding interpretation of our data from banded iron formations. We are investigating experimentally how Ni isotopes fractionate during adsorption and co-precipitation with substrates relevant to incorporation of dissolved Ni into marine sediments.

NSF Major Research Instrumentation

"Acquisition of a multi-collector ICP-MS for Indiana University." (Co-investigators Lisa Pratt and Ed Ripley, Indiana University)

This grant supports the purchase of an instrument to measure very precisely the ratios of stable and radiogenic isotopes of almost any element. An ambitious, multi-disciplinary team of investigators uses the instrument for a wide range of investigations in geological, environmental, and biological contexts. The grant also provides partial support for a lab manager.