9601577 Brown This grant provides $136,000 as partial support of the costs of acquiring an inductively coupled plasma mass spectrometer (ICP-MS) for trace elemental and isotopic ratio analyses for studies in limnology and paleoclimatology at the University of Minnesota - Duluth, Large Lakes Observatory. Specific research will focus on anthropogenic influences on heavy metal (particularly Pb and Cu) distributions and their subsequent diagenetic remobilization in sediments of Lake Superior and studies of redox sensitive metals, trace metal ratios (i.e. Mg/Ca, Sr/Ca) in ostracode tests and the Pb and Sr isotopic variations found in lithic fragments from East African Rift Lake sediments as proxies of climatic and provenance changes over time. This instrument will provide a new regional capability for trace elemental analyses of environmental samples and will benefit undergraduate and graduate students conducting limnological and geochemical research. ***