DAVID JOHNSTON

Graduate Student
Department of Geology
University of Maryland
College Park, Maryland 20742, USA
Tel: (301) 405-7056
Fax: (301) 314-9661
dtj@geol.umd.edu

Research Interests
The isotopic study of the activity and evolution of sulfur utilizing prokaryotes as it pertains to the evolution of the surface sulfur cycle and rise of atmospheric oxygen. In particular, I utilize the stable sulfur isotopes (32S, 33S, 34S, and 36S) in the experimental study of microbial fractionations, in the geochemical evaluation of Proterozoic sediments (CAS and shales), and finally as a constraint on global and microbial scale sulfur models. My interests also involve the general evolution of the biosphere and questions pertaining to astrobiology.

CV

Johnston et al. 2005a

Johnston et al. 2005b

Johnston et al. 2006

Farquhar et al. 2003

Ono et al. 2006