Paleocene paleogeography

Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around (Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pangaea, drifting further north after the split and finally broke apart with the opening of the North Atlantic Ocean 56 Mya. The name is a portmanteau of Laurentia and Eurasia.

large inland sea during the mid- to late Cretaceous and the very early Paleogene; split North America into Laramidia and Appalachia; stretched from the Gulf of Mexico to the Arctic Ocean; at its largest, it was 760 m deep, 970 km wide, 3200 km long

historic ocean