Western U.S. (Great Basin)
Fieldwork in the eastern Great Basin (Nevada, Utah) is focused on
obtaining high-resolution carbon (carbonate and organic mattter) and strontium isotope trends and relative
sea level history for the Ordovician (with graduate student Seth Young) and Carboniferous Greenhouse-Icehouse transition (with graduate students Kate Tierney and Brad Cramer).
I have worked in detail on a spectacularly exposed
succession in the Arrow Canyon Range of southeastern Nevada (pictured below) which is well-dated using biostratigraphy. This work is in collaboration with Ken Foland at Ohio State (Sr isotopes), Ben Gill and Tim Lyons (sulfur isotope stratigraphy) at Univ California - Riverside, and Lee Kump at Penn State. This work is currently supported by NSF and will build upon the Great Basin composite carbon isotope curve published in Geology in 2005 (see Paleozoic2005 link above).
Northern Rocky Mountains (Wyoming and Montana)
The Paleozoic geology of Wyoming and surrounding areas of Utah and Montana has been
an active area of research because of its transtional paleotectonic
setting between the rapidly subsiding Great Basin and the cratonal
sequences in the midcontinent (see work with Tony Runkel and Clint Cowan below). Projects in the Late Cambrian and Mississippian
(Madison Limestone) are aimed at evaluation of roles of eustasy versus
tectonics as drivers of relative sea level changes in the region.
Western europe (Dinant Basin)
Field study in southern Belgium, in collaboration with Luc
Hance, Eric Groessens, and Francois-Xavier Devuyst, looked at the chemo-, bio- and sequence stratigraphic
signatures to compare with Nevada.
Midcontinent, U.S. (Upper Mississippi Valley)
Cambrian mass extinctions of trilobites (biomere boundaries) occur
within meters of major sequence boundaries in the western U.S. and I am
working with Clint Cowan (Carleton College) and Tony Runkel (Minnesota
Geological Survey) to compare signals in nearshore environments of Minnnesota,
Iowa and Wisconsin.