A 20,000-year record of environmental change from Laguna Kollpa Kkota, Bolivia

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5578808

Seltzer, G O ^[1]; Abbott, M B ^[2]

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1. Byrd Polar Research Center, Columbus, OH (United States). Mendenhall Lab.
2. 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--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ANDES
BOLIVIA
CENOZOIC ERA
CLIMATIC CHANGE
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
GLACIERS
LAKES
LATIN AMERICA
MOISTURE
MORAINES
MOUNTAINS
PALEOCLIMATOLOGY
PALEONTOLOGY
PALEOTEMPERATURE
PLEISTOCENE EPOCH
QUATERNARY PERIOD
SEDIMENTATION
SOUTH AMERICA
STRATIGRAPHY
SURFACE WATERS