Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Clechenko, E. R. Articles by Stiles, C. A. Search for Related Content GeoRef GeoRef Citation

Terrestrial records of a regional weathering profile at the Paleocene-Eocene boundary in the Williston Basin of North Dakota

Elizabeth R. Clechenko^,1, D. Clay Kelly^,1, Guy J. Harrington^,2 and Cynthia A. Stiles^#,3

¹ Department of Geology and Geophysics, University of Wisconsin–Madison, 1215 W. Dayton Street, Madison, Wisconsin 53706, USA
² School of Geography, Earth and Environmental Sciences, University of Birmingham, Aston Webb Building, Birmingham B15 2TT, UK
³ Department of Soil Science, University of Wisconsin–Madison, 1525 Observatory Drive, Madison, Wisconsin 53706, USA

The "orange zone" within the Bear Den Member of the Golden Valley Formation (Williston Basin, North Dakota) represents a terrestrial weathering profile formed by intense pedogenesis during an ancient (ca. 55 Ma) global warming event referred to as the Paleocene-Eocene thermal maximum. Distinctive features of the orange zone include: (1) high abundances of kaolinite, (2) a strongly leached character with a bright orange iron-enriched horizon, (3) poor organic carbon preservation, and (4) ferric pans/pisoliths at its basal contact, equivalent to modern lateritic materials. Though conclusive evidence, such as a distinctive Paleocene-Eocene thermal maximum flora and/or definitive carbon isotope excursion, is lacking, the stratigraphic succession of palynofloral datums preserved within the upper part of the Bear Den orange zone is similar to that associated with the later stages of other terrestrial Paleocene-Eocene thermal maximum records from the U.S. Western Interior. Bulk ¹³ C_org ratios decrease through the orange zone as well, but the magnitude of this isotopic decrease is less than that of the carbon isotope excursion. Thus, the collective evidence indicates that the early initial stages of the Paleocene-Eocene thermal maximum are either preserved within the barren, condensed interval of the lower orange zone or are missing altogether from the Williston Basin stratigraphy, and that the orange zone likely developed during the later recovery stages of the Paleocene-Eocene thermal maximum. The Williston Basin records generally agree with the tenet that continental weathering intensified during the Paleocene-Eocene thermal maximum. Moreover, these records indicate that the paleohydrology of the basin varied markedly and that sequestration of terrestrial organic carbon was greatly reduced as this transient global warming event unfolded.

Key Words: Paleocene-Eocene thermal maximum • Williston Basin • kaolinite • Golden Valley Formation

This article has been cited by other articles:

				E.H. Gierlowski-Kordesch, A.D. Jacobson, J.D. Blum, and B.L. Valero Garces Watershed reconstruction of a Paleocene Eocene lake basin using Sr isotopes in carbonate rocks GSA Bulletin, January 1, 2008; 120(1-2): 85 - 95. [Abstract] [Full Text] [PDF]