First steps on land: Arthropod trackways in Cambrian-Ordovician eolian sandstone, southeastern Ontario, Canada
- Robert B. MacNaughton1,
- Jennifer M. Cole2,
- Robert W. Dalrymple2,
- Simon J. Braddy3,
- Derek E.G. Briggs3 and
- Terrence D. Lukie4
- 1Geological Survey of Canada, 3303-33rd Street NW, Calgary, Alberta T2L 2A7, Canada
- 2Department of Geological Sciences and Geological Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada
- 3Department of Earth Sciences, University of Bristol, Bristol, Queens Road BS8 1RJ, UK
- 4Nexen Canada Ltd., 801-7th Avenue SW, Calgary, Alberta T2P 3P7, Canada
Abstract
Basal terrestrial deposits in the Cambrian-Ordovician Nepean Formation (Potsdam Group) near Kingston, Ontario, contain arthropod-produced trackways that extend the record of the first arthropod landfall back by as much as 40 m.y. The presence of large, simple cross-beds and of wind-produced structures, including adhesion ripples and wind-ripple lamination, indicates that the host strata were deposited in an eolian dune field, probably in a marginal-marine setting. The trackways were preserved mainly as undertracks and record the activities of large, amphibious arthropods, possibly euthycarcinoids.
Footnotes
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↵*Present address: Department of Geology and Geophysics, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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- Accepted January 14, 2002.
- Received June 18, 2001.
- Revision received December 26, 2001.
- Geological Society of America
