Extraterrestrial demise of banded iron formations 1.85 billion years ago

52Citations
Citations of this article
104Readers
Mendeley users who have this article in their library.
Get full text

Abstract

In the Lake Superior region of North America, deposition of most banded iron formations (BIFs) ended abruptly 1.85 Ga ago, coincident with the oceanic impact of the giant Sudbury extraterrestrial bolide. We propose a new model in which this impact produced global mixing of shallow oxic and deep anoxic waters of the Paleoproterozoic ocean, creating a suboxic redox state for deep seawater. This suboxic state, characterized by only small concentrations of dissolved O2 (∼1 μM), prevented transport of hydrothermally derived Fe(II) from the deep ocean to continental-margin settings, ending an ∼1.1 billion-year-long period of episodic BIF mineralization. The model is supported by the nature of Precambrian deep-water exhalative chemical sediments, which changed from predominantly sulfide facies prior to ca. 1.85 Ga to mainly oxide facies thereafter. © 2009 Geological Society of America.

Cite

CITATION STYLE

APA

Slack, J. F., & Cannon, W. F. (2009). Extraterrestrial demise of banded iron formations 1.85 billion years ago. Geology, 37(11), 1011–1014. https://doi.org/10.1130/G30259A.1

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free