LATE-GLACIAL STAGE AND HOLOCENE TROPICAL ICE CORE RECORDS FROM HUASCARAN, PERU

Two ice cores from the col of Huascaran in the north-central Andes of Peru contain a paleoclimatic history extending well into the Wisconsin an (Wurm) Glacial Stage and include evidence of the Younger Dryas cool phase. Glacial stage conditions at high elevations in the tropics app ear to have been as much as 8 degrees to 12 degrees C cooler than toda y, the atmosphere contained about 200 limes as much dust, and the Amaz on Basin forest cover may have been much less extensive. Differences i n both the oxygen isotope ratio delta(18)O (8 per mil) and the deuteri um excess (4.5 per mil) from the Late Glacial Stage to the Holocene ar e comparable with polar ice core records. These data imply that the tr opical Atlantic was possibly 5 degrees to 6 degrees C cooler during th e Late Glacial Stage, that the climate was warmest from 8400 to 5200 y ears before present, and that it cooled gradually, culminating with th e Little Ice Age (200 to 500 years before present). A strong warming h as dominated the last two centuries.