Professor Fike is interested in the detailed working of global biogeochemical cycles, their evolution over Earth history, and their impact on biological evolution. Stable Isotope Biogeochemistry involves the analysis and interpretation of the stable isotopic compositions of a variety of elements that make up minerals and organic matter. In the modern, stable isotope biogeochemistry is used to understand biological cycling within microbially-dominated environments (e.g., microbial mats, or marine sediments), reconstruct larger-scale ecosystem dynamics and food webs, and trace the development of human agriculture (e.g., the spread of maize domestication). Isotope studies of carbon and sulfur in sedimentary strata provide one of the most powerful tools for reconstructing environmental change throughout Earth history, particularly oxygenation events during both the Paleoproterozoic (~2.2-2.5 billion years ago) and the late Neoproterozoic (~635 - 541 million years ago). On a global-scale, these isotopes provide the best estimate for global biological productivity as well as the burial of both reduced carbon (organic matter) and sulfur (pyrite), which are the two dominant factors that regulate atmospheric oxygen levels (pO2). Ongoing projects include mapping the evolution of carbon and sulfur cycling during the course of the Cambrian ‘Explosion’ using sedimentary carbonates from the Anti-Atlas Mountains of Morocco, the deposition of Ediacaran and Phanerozoic sulfate evaporites, the study of modern acidic sulfates as analogs for Martian environments, and the mapping of micron-scale sulfur cycling in modern microbial mats and sedimentary environments. These projects combine a mixture of fieldwork, laboratory extractions and isotope analyses, and modeling.
Fike, D. A. 2010. Earth's redox evolution. Nature Geoscience, 3: 453 - 454.
Fike, D. A. & Grotzinger, J. P. 2010. "Reconstructing pyrite burial in evaporite basins: an example from the Ara Group, Sultanate of Oman", Geology, 38(4): 371 - 374.
Fike, D. A., Finke, N., Zha, J., Blake, G., Hoehler, T. M. & Orphan, V. J. 2009. "The effect of sulfate concentration on (sub)millimeter-scale sulfide ?34S in hypersaline cyanobacterial mats over the diel cycle", Geochimica et Cosmochimica Acta, 73: 6187 - 6204.
Fike, D. A., Gammon, C. L., Ziebiz, W., & Orphan, V. J. 2008. "Micron-scale mapping of sulfur cycling across the oxycline of a cyanobacterial mat: a combined nanoSIMS and CARD-FISH approach", International Society of Microbial Ecology Journal, 2: 749 - 759.
Fike, D. A. & Grotzinger, J. P. 2008. "A paired sulfate-pyrite ?34S approach to understanding the evolution of the Ediacaran-Cambrian sulfur cycle", Geochimica et Cosmochimica Acta, 72(11): 2636 - 2648.
Fike, D. A., Grotzinger, J. P., Pratt, L. M, & Summons, R. E.. 2006. "Oxidation of the Ediacaran Ocean", Nature, 444: 744 - 747.
Engineering the Climate, Earth History, Advanced Earth History, Sedimentary Geology