CRETACEOUS

Some links to interesting web sites on the Cretaceous are provided at the bottom of this page... The Cretaceous Period, which lasted for some 80 million years (144.2 to 65.0 mya), saw a number of important geological changes, including the opening of the Atlantic Ocean which commenced in the Jurassic, and the closing of the Tethys Ocean in the course of the Alpine orogeny. The global climate was warmer than today and the earth had no significant ice caps. Thus oceanic circulation triggered by cold water formation in the polar regions was largely lacking... Unconformities in the Upper Cretaceous sedimentary sequence attest to a changeable morphology due to salt migration in the underground. Faunistic studies (e.g. Christensen, 1997) have demonstrated that the shallow (50 to 100 m) Campanian seas in the Hannover region were connected to the northern (boreal) ocean, but had little exchange with the tropical Tethys in the south.