Environmental Sciences, Geological Sciences, Geology and Geochemistry
University of Pittsburgh
We use a combination of organic and stable isotopic biogeochemical techniques to investigate the biogeochemical record of environmental change preserved in aquatic sedimentary systems – especially lake and ocean sediments. Specific organic compounds called biomarkers, or molecular fossils, can be traced to the organism that produced them. Thus, from looking at organic remains in sediments, we can identify variations in the surrounding vegetation (trees and grasses), the aquatic phytoplanktonic community, as well as the micobial community (bacteria and archaea) that have occurred in the past, and use this information to understand global climate and environmental change. Current projects include sulfur isotope biogeochemistry in sulfidic lakes in the USA and Canada considered modern analogs of the Precambrian ocean, development of Pleistocene paleoclimate reconstructions and their link with human societies in southwestern North America (New Mexico, Arizona, Mexico), western South America (Chile, Peru) and East Africa (Malawi, Kenya, Ethiopia), and the development of molecular isotopic proxies for past temperature and hydrology.