Special Section: Paleoceanography of Paleozoic Midcontinental Seaways
Bryozoan bathymetric gradients within a Late Ordovician Epeiric Sea
Article first published online: 4 MAY 2010
Copyright 1987 by the American Geophysical Union.
Volume 2, Issue 2, pages 165–176, April 1987
How to Cite
1987), Bryozoan bathymetric gradients within a Late Ordovician Epeiric Sea, Paleoceanography, 2(2), 165–176, doi:10.1029/PA002i002p00165., , and (
- Issue published online: 4 MAY 2010
- Article first published online: 4 MAY 2010
- Manuscript Accepted: 26 DEC 1986
- Manuscript Received: 27 MAY 1986
The large-scale spatial zonation of the Late Ordovician epeiric sea in North America is reflected in the distributions of bryozoans and other invertebrates. Their major life zones (biomes) reflect changing patterns of sedimentation across the platform, from major siliciclastic to carbonate lithotopes. Deeper water within the epeiric sea most likely existed in an area centered on the Michigan Basin and between the clastic wedges of the Taconic Orogen and the extensive cratonic carbonate platform. Stratigraphic gradients in the Cincinnati Arch area indicate a first-order cycle of transgression-regression throughout the Late Ordovician, on which second-order fluctuations in sea level have been superimposed. The second-order fluctuations indicate three transgressive-regressive subcycles, closely corresponding to the Eden, Maysville, and Richmond stages.