9321910 Biscaye This award is for support for a one year project to apply a variety of natural tracer techniques to the varying concentrations of dust in the Greenland Ice Sheet Project Two (GISP2) ice core, during the period from the Older Dryas to the Pre-Boreal, and to the varying dust concentrations deposited during the stadials and interstadials which correspond to Heinrich Events H4 and H3. Several natural tracers including mineralogical analysis, isotopic analysis of aluminosilicates (Strontium, and Neodymium) and of soluble minerals such as calcite and gypsum (Oxygen, Sulfur and Carbon), and pollen analysis are proposed to help determine the origins of this material. Preliminary work on ice core samples from the last glacial maximum (LGM) have demonstrated significant mineralogical variation, indicating a southward shift in dust source area between samples from a lower-dust, interstadial period and a higher-dust, stadial period about 700 years apart. With this information, net airmass transport pathways can be used to aid in the modeling of atmospheric paleocirculation patterns. ***