Interior Plains

Interior Plains

The Interior Plains is a vast physiographic region that spreads across the Laurentian craton of North America. This area was originally formed when cratons collided and welded together 1.9–1.8 billion years ago in the Trans-Hudson orogeny during the Paleoproterozoic.

Precambrian metamorphic and igneous rocks now form the basement of the Interior Plains and make up the stable nucleus of North America. With the exception of the Black Hills of South Dakota, the entire region has low relief, reflecting more than 500 million years of relative tectonic stability. USGS description of the U.S. Interior Plains region]

The Great Plains region of the United States and Canada falls within this area. The interior Plains were often covered by shallow inland sea. Sediments from the shield and the Rocky Mountains were deposited in these seas over millions of years. Eventually the sediments were compressed by the weight of the layers above into sedimentary rock. Part of the sedimentary rock deposited in these areas consists of coral reefs that formed close to the surface of seas during the Paleozoic era.

Geology and physiography

The Interior Plains are a vast physiographic division encompassing 8 distinct physiographic provinces, the Interior Low Plateaus, Great Plains, Central Lowland, Mackenzie Delta, Manitoba Lowlands, Northern Boreal Plains, Prairie Grasslands, and the Southern Boreal Plains And Plateaux.cite web |title=Physiographic divisions of the conterminous U. S. |publisher=U.S. Geological Survey |url= |accessdate=2007-12-06 ] [cite web |last=|first=| authorlink = | coauthors = |title=The Atlas of Canada |publisher=Natural Resources Canada |date=|url= |accessdate=2007-12-27 ]

Paleozoic and Mesozoic

Throughout the Paleozoic and Mesozoic eras, the mostly low-lying Interior Plains region remained relatively unaffected by the mountain-building tectonic collisions occurring on the western and eastern margins of the continent. During much of the Mesozoic Era, the North American continental interior were mostly well above sea level, with two major exceptions. During part of the Jurassic, rising seas flooded the low-lying areas of the continent, forming the Sundance Sea; in the Cretaceous, much of the Interior Plains region lay submerged beneath the Western Interior Seaway.


The Interior Plains continued to receive deposits from the eroding Rocky Mountains to the west and Appalachian and Ozark/Ouachita Mountains to the east and south throughout the era. The flatness of the Interior Plains is a reflection of the platform of mostly flat-lying marine and stream deposits laid down in the Mesozoic and Cenozoic eras.


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  • Interior Plains — Auf der Karte von Nordamerika sind die Interior Plains rot markiert. Die Interior Plains sind eine große physiogeographische Region des Urkontinents Laurentia im heutigen Nordamerika. Sie entstanden als Kratone vor 1,8 bis 1,9 Millionen Jahren in …   Deutsch Wikipedia

  • Interior Plains — Canada’s great plains …   Eponyms, nicknames, and geographical games

  • Interior Plains — noun A large region of North America formed by the collision of cratons in the Paleoproterozoic …   Wiktionary

  • Plains Indian — a member of any of the American Indian tribes, as those of the Algonquian, Athabascan, Caddoan, Kiowa, Siouan, or Uto Aztecan linguistic families, that formerly inhabited the Great Plains. All were more or less nomadic, following the buffalo, and …   Universalium

  • Interior Lowlands — ▪ region, North America       the broad, generally flat areas of the central part of the North American continent. The name is used in regional geologic and physiographic descriptions of North America and the conterminous United States. From the… …   Universalium

  • Great Plains — For other uses, see Great Plains (disambiguation). Coordinates: 37°N 97°W / 37°N 97°W / 37; 97 …   Wikipedia

  • Geography of the Interior United States — the games at the great lake are held in the winter so none can live they realy dont want otters or bubble gum to live either. so just go die Physiographic regions of the U.S. Interior See:legend For purposes of description, the physical geography …   Wikipedia

  • Osage Plains — The Osage Plains extend through five U.S. states. The Osage Plains are a physiographic section of the larger Central Lowland province, which in turn is part of the larger Interior Plains physiographic division.[1] The area is sometimes called the …   Wikipedia

  • Dissected Till Plains — Continental U.S physiographic regions. Region 12e identifies the Dissected Till Plains. The Dissected Till Plains are physiographic sections of the Central Lowlands province, which in turn is part of the Interior Plains physiographic division of… …   Wikipedia

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