The history of Great Plains climate and the responses of the physical and biologic systems to climate changes in the last 10,000 yrs. need to be well understood if we are to make accurate predictions of the consequences of global warming for this region. Several global climate models have projected the Great Plains as the most likely region in the U.S. to experience prolonged drought conditions in the next decades. In this light, the chronology and paleoclimatic interpretations of sand dune formation and activity in the now-stabilized dunes which occupy some 50,000 km of west- central Nebraska--the Nebraska Sand Hills-- take on considerable importance. Although some workers believe that the major period of dune activity coincided with the maximum advance of continental glaciers (about 18,000 years ago) and the most of the dunes have been stable since that time, evidence is accumulating that much of the dune field, although possibly formed during the Ice Age, has been remobilized several times in the last 10,000 years. The organic-rich lake or marsh sediments that formed between stabilized dunes can be radiocarbon-dated. If only one or two samples from a single interdune area are dated, the history of deposition appears simple. Additional dated samples may show that the filling interdune swales was episodic, not gradual; gaps in the record should coincide with periods of moving dunes. Many more radiocarbon dates from strategically-located core and drill holes across interdunes and dunes to settle the controversy surrounding the history of the Sand Hills.
