India's Cretaceous deposits include the Deccan traps, a large, thick sequence of volcanic rocks east of Bombay. There are Cretaceous rocks in west Africa and Mozambique. Russia and the southwestern Asian republics have Cretaceous rocks. Other deposits are in Denmark, north and central Germany, central and southern France, the Pyrenees Mountains, the Alps, Italy, Slovenia, coastal Croatia, Bosnia and Hercegovina, and Yugoslavia. In Europe, Cretaceous chalk also crops out around the Paris basin. A vast volcanic province in the ParanÃ¡ River basin of Uruguay and Brazil is mirrored across the Atlantic Ocean in the Etendeka province of western Africa, regions that were joined before South America and Africa separated. Cretaceous outcrops cover parts of central and southeastern South America. This group extends along the Andes Mountain belt from Colombia to Cape Horn, and onto Antarctica. Cretaceous rocks crop out on several Caribbean islands. Volcanoes in the western United States spread layers of volcanic ash, now turned into bentonite, in the center of the continent. They extend throughout the Rocky Mountains and western Plains states, around the north edge of the Mississippi embayment, and along the southern and eastern sides of the Appalachian Mountains. Thick Cretaceous sedimentary deposits form a narrow belt of outcrops from British Columbia to Central America. Because of the great extent of their outcrop area and presence in drill cores, Cretaceous rocks are the most intensively studied part of the Phanerozoic rock column.Īt one time Cretaceous seas covered 50% of the present North American continent. These names, based on type localities where rocks at a given stratigraphic level were first studied, are widely used to refer to rock units or chronological times.Ĭretaceous rocks make up nearly 29% of the total area of Phanerozoic deposits on the Earth's landmasses. The Cretaceous System is subdivided into the following stages from youngest to oldest: Upper Cretaceous includes Maastrichtian, Campanian, Santonian, Coniacian, Turonian, and Cenomanian Lower Cretaceous includes Albian, Aptian, Barremian, Hauterivian, Valanginian, and Berriasian.

Tectonic plates moved apart, causing major mountain building, and continents began to resemble those existing today. During the Cretaceous more land was submerged than at any time since the Ordovician Period.

In 1822, Omalius d'Halloy termed the chalky rocks (Latin: 'creta') found on the English and French sides of the English Channel 'Cretaceous.' The name is now applied to all materials deposited above Jurassic Period rocks but below Tertiary Period rocks.

The Cretaceous Period is the most recent period of the Mesozoic Era, spanning 77 million years, from 142 million to 65 million years ago.

Earth during the cretaceous period