Current Research Interests
Aqueous geochemistry, Geochemical kinetics, Biogeochemistry
Susan L. Brantley is Professor of Geosciences and Director of the Center
for Environmental Chemistry and Geochemistry. Brantley's career as a
geochemist has taken her from the deserts of Peru to the glaciers of
Iceland. In contrast to many geologists who are strictly interested in rocks
and their formations, her work focuses on the chemistry of natural waters
both at the surface of the earth and deeper in the crust. Much of her
research is an attempt to understand what controls the chemistry of
natural water, and how water interacts with the rocks through which it
flows.
In laboratory experiments Brantley and her students measure how fast
reactions proceed between minerals and water, and in their field work they
attempt to document that the laboratory simulations can indeed predict
processes in the field. Support for Brantley's research has been provided
by the National Science Foundation, which awarded her a Presidential
Young Investigator Award in 1987, and by the David and Lucile Packard
Foundation, which awarded her a Packard Fellowship in the same year.
Brantley is currently funded by the National Science Foundation, the
Department of Energy, NASA, and the Petroleum Research Fund..
Several graduate students studying under Brantley have focused on the hydrogeochemistry of active volcanoes: Volcan Poas in Costa Rica, Grimsvotn in Iceland, and Ol'Doinyo Lengai in Tanzania. Currently, Brantley is supervising an investigation in Yellowstone National Park to measure the flux of carbon dioxide into the atmosphere from the park's geothermal features. Another graduate student is completing a project to investigate degassing in California on the San Andreas fault.
These field projects are all complemented by ongoing studies in the laboratory in which Brantley and her students simulate natural processes in controlled systems so as to
predict the rates and mechanisms of processes in the field. Measuring the
dissolution rate of feldspar, the most common mineral in the Earth's crust, is
enabling other earth scientists to better predict the rate of erosion of the
continental masses. Such rate measurements have never before been
applied successfully to any natural system, and Brantley's students are
focusing on questions concerning why laboratory measured rates always
appear slower than field measured rates. Of particular interest to members
of Brantley's group are questions concerning mineral surface area and
porosity, and questions concerning interactions between soil microbes and
mineral grains. Laboratory research in these areas exploits the rich
endowment of analytical facilities on campus including state-of-the-art
instrumentation for solid, liquid, and interface characterization maintained as
part of the Material Characterization Laboratory and the Center for Environmental Chemistry and Geochemistry/CECG). Brantley supervises the CECG-sponsored High Resolution Inductively Coupled Plasma Mass Spectrometer. Much of the research of Brantley's group is summarized at: www.essc.psu.edu/~brantley.
The newest educational initiative spearheaded by Brantley and the CECG is the Biogeochemical Research Initiative for Education. BRIE is an NSF-funded initiative to support up to 5 post docs, 30 graduate and 30 undergraduate students to investigate the interface of microbiology and geochemistry at Penn State. Grad and undergrad applicants are encouraged to apply. Brantley's interests within BRIE focus upon investigations of bacteria-enhanced mobilization of trace metals and organics from weathering minerals.