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Episodes of low dissolved oxygen indicated by ostracodes and sediment geochemistry at Crystal Lake, Illinois, USA

Limnology and Oceanography

By:
,
DOI: 10.4319/lo.2010.55.6.2403

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Abstract

Low dissolved oxygen during the summer and early fall controls profundal continental ostracode distribution in Crystal Lake (McHenry County), Illinois, favoring Cypria ophthalmica and Physocypria globula at water depths from 6 to 13 m. These species also thrived in the lake's profundal zone from 14,165 to 9600 calendar year before present (cal yr b.p.) during the late Boiling, Allerod, and Younger Dryas chronozones, and early Holocene. Characterized by sand, cemented tubules, large aquatic gastropod shells, and littoral ostracode valves, thin (1-6 cm) tempestite deposits punctuate thicker deposits of organic gyttja from 16,080 to 11,900 cal yr b.p. The succeeding 2300 yr (11,900-9600 cal yr b.p.) lack tempestites, and reconstructed water depths were at their maximum. Deposition of marl under relatively well-oxygenated conditions occurred during the remainder of the Holocene until the arrival of Europeans, when the lake returned to a pattern of seasonally low dissolved oxygen. Such conditions are also indicated in the lake sediment by the speciation of phosphorus, high concentrations of organic carbon, and abundant iron and manganese occluded to mineral grains. Initial low dissolved oxygen was probably caused by the delivery of dissolved P and Fe in shallow groundwater, the chemistry of which was influenced by Spodosol pedogenesis under a spruce forest. The triggering may have been regionally warm and wet conditions associated with retreat of the Lake Michigan lobe (south-central Laurentide Ice Sheet). ?? 2010, by the American Society of Limnology and Oceanography Inc.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Episodes of low dissolved oxygen indicated by ostracodes and sediment geochemistry at Crystal Lake, Illinois, USA
Series title:
Limnology and Oceanography
DOI:
10.4319/lo.2010.55.6.2403
Volume
55
Issue:
6
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Limnology and Oceanography
First page:
2403
Last page:
2423
Number of Pages:
21