A late-glacial to early Holocene record of pollen, plant macrofossils, and charcoal has been obtained from two cores from Browns Pond in the central Appalachians of Virginia. An AMS radiocarbon chronology defines the timing of moist and cold excursions, superimposed on the overall warming trend from 14,200 to 7500 C-14 yr B.P. This site had cold, moist conditions from ca. 14,200 to 12,700 C-14 yr B.P., with warming at 12,730, 11,280, and 10,050 C-14 yr B.P. A decrease in deciduous broadleaved tree taxa and Pinus strobus (haploxylon) pollen, simultaneous with a reexpansion of Abies, denotes a brief, cold reversal from 12,260 to 12,200 C-14 yr B.P. A second cold reversal, inferred from increases in montana conifers, is centered at 7500 C-14 yr B.P. The cold reversals at Browns Pond may be synchronous with climate change in Greenland and northwestern Europe. Warming at 11,280 C-14 yr B.P. shows the complexity of regional climate responses during the Younger Dryas chrono-zone. (C) 1999 University of Washington.
182MVTimes Cited:13Cited References Count:92