This grant supports acquisition of a stable isotope ratio mass spectrometer (SIRMS) for environmental and paleoclimate research as well as modern ecological studies, hydrology, limnology, and aqueous geochemistry at the University of Minnesota. A continuous flow (CF) mass spectrometer with on-line peripheral devices that prepare samples automatically and introduce the purified gases directly into the ion source will be purchased, replacing a 20-year old Finnigan MAT delta E that was decommissioned in 2001. The CF-SIRMS will reduce the size of samples needed to be processed and therefore allow higher resolution studies of sample sequences to take place and increase sample throughput and precision. Research that will immediately benefit from the capabilities of the requested SIMRS include: 1) studies of modern interactions between surface and groundwaters in the mid-continental U.S. as recorded in the isotopic composition of the remains of lacustrine dwelling planktonic microflora and fauna and related paleorecords studies with implications for understanding past climate variability in the mid-continent; 2) carbon balance investigations in lakes and wetlands; 3) investigations of Cenozoic mammalian paleodiets through stable isotopic analysis of fossil biogenic apatite with implications for elucidating the paleoenvironments of extinct organisms; and 4) regional Quaternary paleoclimate investigations based on stable isotopic analysis of speleothem calcite. The instrument will be also used to train postdocs and graduate students from a variety of departments. To foster interdisciplinary work, a seminar will be offered every two years where faculty and students will talk about their research, focusing on the role of isotope analyses. Undergraduate students participating in the university's REU program will be involved in research that uses the new instrumentation. Indian reservations will also be visited where talks on the food web and hydrologic/sediment cycle will be presented.
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