A 20,000-year record of environmental change from Laguna Kollpa Kkota, Bolivia
- Byrd Polar Research Center, Columbus, OH (United States). Mendenhall Lab.
- Limnological Research Center, Minneapolis, MN (United States)
Most records of paleoclimate in the Bolivian Andes date from the last glacial-to-interglacial transition. However, Laguna Kollpa Kkota and other lakes like it, formed more than 20,000 yr BP when glaciers retreated and moraines dammed the drainage of the valleys they are located in. These lakes were protected from subsequent periods of glaciation because the headwalls of these valleys are below the level of the late-Pleistocene glacial equilibrium-line altitude. The chemical, mineral, and microfossil stratigraphies of these glacial lakes provide continuous records of environmental change for the last 20,000 years that can be used to address several problems in paleoclimate specific to tropical-subtropical latitudes. Preliminary results from Laguna Kollpa Kkota indicate that glacial equilibrium-line altitudes were never depressed more than 600 m during the last 20,000 years, suggesting that temperatures were reduced only a few-degrees celsius over this time period. Sedimentation rates and the organic carbon stratigraphy of cores reflect an increase in moisture in the late Pleistocene just prior to the transition to a warmer and drier Holocene. The pollen and diatom concentrations in the sediments are sufficient to permit the high resolution analyses needed to address whether or not there were climatic reversals during the glacial-to-interglacial transition.
- OSTI ID:
- 5578808
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BOLIVIA
PALEOCLIMATOLOGY
ANDES
CLIMATIC CHANGE
GLACIERS
LAKES
MOISTURE
MORAINES
PALEOTEMPERATURE
PLEISTOCENE EPOCH
SEDIMENTATION
STRATIGRAPHY
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
LATIN AMERICA
MOUNTAINS
PALEONTOLOGY
QUATERNARY PERIOD
SOUTH AMERICA
SURFACE WATERS
580000* - Geosciences