Century-scale paleoclimatic reconstruction from Moon Lake, a closed-basin lake in the northern Great Plains

Authors

• Kathleen R. Laird, University of Minnesota, MinneapolisFollow
• Sherilyn C. Fritz, University of Nebraska-LincolnFollow
• Eric C. Grimm, Illinois State Museum, Research and Collections Center, Springfield
• Pietra G. Mueller, Illinois State Museum, Research and Collections Center, Springfield

Document Type

Article

Date of this Version

February 1996

Comments

Published in Limnol. Oceanogr., 41(5), 1996, 890-902. Copyright 1996, by the American Society of Limnology and Oceanography, Inc. Used by permission.

Abstract

Estimates of past lake-water salinity from fossil diatom assemblages were used to infer past climatic conditions at Moon Lake, a climatically sensitive site in the northern Great Plains. A good correspondence between diatom-inferred salinity and historical records of mean annual precipitation minus evapotranspiration (P - ET) strongly suggests that the sedimentary record from Moon Lake can be used to reconstruct past climatic conditions. Century-scale analysis of the Holocene diatom record indicates four major hydrological periods: an early Holocene transition from an open freshwater system to a closed saline system by 7300 B.P., which corresponds with a transition from spruce forest to deciduous parkland to prairie and indicates a major shift from wet to dry climate; a mid-Holocene period of high salinity from 7300 to 4700 B.P., indicating low effective moisture (P - ET); a transitional period of high salinity from 4700 to 2200 B.P., characterized by poor diatom preservation; and a late Holocene period of variable lower salinity during the past 2,200 yr, indicating fluctuations in effective moisture.