Iron Formation: the Sedimentary Product of a Complex Interplay Among Mantle, Tectonic, Oceanic, and Biospheric Processes *
©2010 Society of Economic Geologists, Inc. Economic Geology, v. 105, pp. 467–508 Iron Formation: The Sedimentary Product of a Complex Interplay among Mantle, Tectonic, Oceanic, and Biospheric Processes * ANDREY BEKKER,1,† JOHN F. SLACK,2 NOAH PLANAVSKY,3 BRYAN KRAPEŽ,4 AXEL HOFMANN,5 KURT O. KONHAUSER,6 AND OLIVIER J. ROUXEL7,8 1Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada 2U.S. Geological Survey, National Center, Mail Stop 954, Reston, Virginia 20192 3Department of Earth Sciences, University of California, Riverside, 900 University Ave., Riverside, California 92521 4The Institute for Geoscience Research, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia 5School of Geological Sciences, University of KwaZulu-Natal, Durban 4041, South Africa 6Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada 7Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Mail Stop 25, 266 Woods Hole Road, Woods Hole, Massachusetts 02543 8Université Européene de Bretagne, IUEM European Institute for Marine Studies, Technopôle Brest-Iroise, Place N. Copernic, 29280 Plouzané, France Abstract Iron formations are economically important sedimentary rocks that are most common in Precambrian sedi- mentary successions. Although many aspects of their origin remain unresolved, it is widely accepted that sec- ular changes in the style of their deposition are linked to environmental and geochemical evolution of Earth. Two types of Precambrian iron formations have been recognized with respect to their depositional setting. Al- goma-type iron formations are interlayered with or stratigraphically linked to submarine-emplaced volcanic rocks in greenstone belts and, in some cases, with volcanogenic massive sulfide (VMS) deposits.
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