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GEOREF RECORD

Surface sample analogues of Elk Lake fossil diatom assemblages

Richard B. Brugam
Surface sample analogues of Elk Lake fossil diatom assemblages (in Elk Lake, Minnesota; evidence for rapid climate change in the north-central United States, J. Platt Bradbury (editor) and Walter E. Dean (editor))
Special Paper - Geological Society of America (1993) 276: 189-214

Abstract

Abundance maps of diatom percentages from 174 Minnesota lakes sediment surface samples show that many diatom species have centers of abundance in lake types from particular regions of the state. Small Stephanodiscus species characterize lakes in the southwestern prairies and in urbanized areas where trophic status is high. Aulacoseira granulata and Stephanodiscus niagarae are most abundant in the shallow, eutrophic lakes of southwestern Minnesota. These geographic associations result from environmental optima for species. Although correlations between particular species and environmental factors show high variance, clear relations can be demonstrated. In particular, the DECORANA program for ordination analysis shows that many species have clearly defined optima either in low- or high-alkalinity lakes. The relations discovered from the surface sample data set can be used to understand the fossil assemblages from Elk Lake, Minnesota. The dominance of small Stephanodiscus species in Elk Lake suggests that the lake has been somewhat eutrophic for most of its history. The appearance of Aulacoseira ambigua and Aulacoseira granulata during the prairie period at Elk Lake implies that the lake was shallower or more turbulent at that time. DECORANA ordination shows that the fossil diatom assemblages of Elk Lake have not changed much since the lake was formed. Thus, environmental changes at Elk Lake were probably very subtle.


ISSN: 0072-1077
EISSN: 2331-219X
Coden: GSAPAZ
Serial Title: Special Paper - Geological Society of America
Serial Volume: 276
Title: Surface sample analogues of Elk Lake fossil diatom assemblages
Title: Elk Lake, Minnesota; evidence for rapid climate change in the north-central United States
Author(s): Brugam, Richard B.
Author(s): Bradbury, J. Platteditor
Author(s): Dean, Walter E.editor
Affiliation: Southern Illinois University, Department of Biological Sciences, Edwardsville, IL, United States
Affiliation: U. S. Geological Survey, Denver, CO, United States
Pages: 189-214
Published: 1993
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 0-8137-2276-4
References: 46
Accession Number: 1993-033223
Categories: Paleobotany
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 7 tables, sketch maps
N47°08'60" - N48°01'60", W95°34'60" - W95°10'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1993
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