About The Research Group
Professor Sheldon's research group studies paleoclimatology, global change, and
biosphere-climate interactions. The group's research investigates linkages between climate
and weathering/soil formation on a variety of spatial and temporal scales using whole
rock geochemistry, light stable isotopes, and modeling to understand past climatic
and environmental change and biogeochemical processes.
Anyone interested in pursuing any of these topics is encouraged
to check ou the research opportunities page or to e-mail Nathan directly.
Cenozoic of Montana
Cenozoic climatic and biotic changes in Montana to understand the role of climatic and environmental change in driving biotic and ecological
changes. We do this using a combination of stable isotope geochemistry, paleosol geochemistry, and phytolith extraction. Overall, we are building
a 40 Myr record of climatic and biotic changes, with a focus on critical transitions including the Eocene-Oligocene transition, the Oligocene-Miocene transition,
and the spread to ecological dominance by the grasses during the Miocene. The project website is here: Montana Project Site
. The project is currently funded by NSF Award #1024535.
Paleoenvironments of Spain
CERG works in Spain on a variety of
different problems ranging from understanding dinosaur habitats in Asturias to reconstructing high-resolution (Milankovitch-scale) paleoclimatic records in the Ebro Basin. In the Ebro Basin,
paleoichnology plays a crucial role in deciphering the paleoecology.
Soil Biogeochemistry and Proxy Development
key outstanding questions is how the terrestrial biosphere will respond to global climatic change. To address this question, CERG uses a variety of isotopic and elemental geochemical
tools to examine nutrient and element cycling. Phytoliths are also extracted to look at short-term paleoecological changes in modern soils. This combination of approaches also makes it
possible to derive proxy relationships for key environmental variables such as precipitation and temperature that can be applied to paleosols to reconstruct paleoclimate. A part of this work focused on modern microbial mat systems is currently funded by NSF Award #1035595.
Precambrian Paleoenvironments and Life on Land
Precambrian paleosols and clastic sediments
often preserve MISS (microbially-induced sedimentary structures) and organic matter that makes it possible to reconstruct what life on land was like during the Precambrian. In addition, the chemical
composition of paleosols may also be used to reconstruct the atmospheric pCO2
. These results are then put into atmospheric chemistry models to understand better
the role of both trace atmospheric gases and of physical factors such as albedo, continental growth, and water vapor. The project is currently funded by NSF Award #1050760.
Dr. Nathan Sheldon
University of Michigan
Dept. of Geological Sciences
2534 CC Little Building
1100 North University Ave.
Ann Arbor, MI 48109-1005