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The GEAT department welcomes Dr. Chad Wittkop from Minnesota State University-Mankato as our next seminar speaker.

Title: Chemical sedimentation processes in ferruginous lakes: Models for primary mineralogy in Precambrian banded iron formations

When: Tuesday, November 14 @ 4:10 pm
Where: 2050 Agronomy Hall

Abstract: The composition of Earth’s early atmosphere co-evolved with microbial life on our planet, and our understanding of this interplay informs our search for biosignatures in the solar system and beyond. Constraints on the composition of Earth’s Precambrian (4.6-0.54 billion years ago) atmosphere will be examined, including evidence from ancient sedimentary rocks such as carbonates, iron formations, and evaporites. Recent controversies regarding carbonate proxies for atmospheric CO2, and iron formation proxies for atmospheric O2 will be examined in light of new evidence from ferruginous lakes. These lakes host deep water layers enriched in dissolved iron, and are thought to closely resemble some aspects of Earth’s early ocean water chemistry. In particular, the role of manganese, methane, and oxygen cycling in the water column will be evaluated as an underrecognized process capable of creating sediment chemical and carbon isotopic signatures traditionally assigned to diagenetic processes.

Bio: Chad Wittkop’s research uses geochemical and geobiological techniques to develop a better understanding of the sedimentary record. He received a B.S. in Geology from Winona State University in 1998, and a Ph.D. in Geology from the University of Minnesota in 2004. He worked as a Quaternary Geologist at the New Hampshire Geological Survey before beginning a teaching career at the University of Wisconsin-Eau Claire. He is presently an Associate Professor at Minnesota State University-Mankato, where he has taught since 2007.