Campus Units
Geological and Atmospheric Sciences
Document Type
Article
Publication Version
Published Version
Publication Date
10-1-2018
Journal or Book Title
Journal of Geophysical Research: Biogeosciences
DOI
10.1029/2018JG004587
Abstract
To elucidate the role of (bio)geochemical processes that fueled iron and carbon cycling in early Earth oceans, modern environments with similar geochemical conditions are needed. As the range of chemical, physical, and biological attributes of the Precambrian oceans must have varied in time and space, lakes of different compositions are useful to ask and answer different questions. Tropical Lake Matano (Indonesia), the largest known ferruginous lake, and Lake Pavin (France), a meromictic crater lake, are the two best studied Precambrian ocean analogs. Here we present seasonal geochemical data from two glacially formed temperate ferruginous lakes: Brownie Lake (MN) and Canyon Lake (MI) in the Upper Midwest, USA. The results of seasonal monitoring over multiple years indicate that (1) each lake is meromictic with a dense, anoxic monimolimnion, which is separated from the less dense, oxic mixolimnion by a sharp chemocline; (2) below this chemocline are ferruginous waters, with maximum dissolved iron concentrations >1 mM; (3) meromixis in Brownie Lake is largely anthropogenic, whereas in Canyon Lake it is natural; (4) the shallow chemocline of Brownie Lake and high phosphorus reservoir make it an ideal analog to study anoxygenic photosynthesis, elemental ratios, and mineralogy; and (5) a deep penetrating suboxic zone in Canyon Lake may support future studies of suboxic microbial activity or mineral transformation.
Copyright Owner
American Geophysical Union
Copyright Date
2018
Language
en
File Format
application/pdf
Recommended Citation
Lambrecht, Nicholas; Wittkop, Chad; Katsev, Sergei; Fakhraee, Mojtaba; and Swanner, Elizabeth D., "Geochemical Characterization of Two Ferruginous Meromictic Lakes in the Upper Midwest, USA" (2018). Geological and Atmospheric Sciences Publications. 261.
https://lib.dr.iastate.edu/ge_at_pubs/261
Included in
Atmospheric Sciences Commons, Biogeochemistry Commons, Geochemistry Commons, Oceanography Commons
Comments
This article is published as Lambrecht, Nicholas, Chad Wittkop, Sergei Katsev, Mojtaba Fakhraee, and Elizabeth D. Swanner. "Geochemical characterization of two ferruginous meromictic lakes in the Upper Midwest, USA." Journal of Geophysical Research: Biogeosciences (2018). doi: 10.1029/2018JG004587. Posted with permission.