OCEANIC BASINS 



MARINE WATERS (EPICONTINENTAL) [s^ 



SEA OR LAND. MORE LIKELY SEA V/r'//7, 



LAND OR SEA. MORE LIKELY LAND L _ T — Z 



LANDS 



^DETERMINATE AREAS 



POLAR 



MARINE CURRENTS 



EQUATORIAL 



Fig. 45 



Paleogeographic map of North America during Middle Ordovician time. 



(Slightly modified after Bailey Willis, courtesy of The Journal of Geology.) 



