why is the ancient coral reefs of the interior plains impor
The Interior Plains is a vast physiographic region that spreads across the Laurentian craton of central North America.his area was originally formed when cratons collided and welded together 1.8â1.9 billion years ago in the Trans-Hudson orogeny during the Paleoproterozoic Era. Precambrian metamorphic and igneous rocks now form the basement of the Interior Plains and make up the stable nucleus of North America.