WARMING AT 18,000-YR-BP IN THE TROPICAL ANDES

Palynological, paleopedological, and glacial geomorphological evidence from the area of the high plain of Bogota in the Colombian Eastern Co rdillera indicates a significant climatic warming around 18,000 C-14 y r B.P. Comparison of dated vegetation changes, pedogenic episodes, and glacier fluctuations provides the basis for defining the so-called '' La Laguna Interstadial'' that lasted from 19,500 to 17,000 yr B.P. Dur ing this interstadial period, mean annual temperatures in the tropical Andes were up to 4 degrees C higher than during the preceding and fol lowing stadial periods, when full-glacial conditions prevailed and tem peratures were up to 8 degrees C colder than at present. (C) 1996 Univ ersity of Washington.