|
The Carboniferous period was marked by vast, coal-forming swamps (see also bog) and a succession of changes in the earth's surface that, continuing into the Permian period, ended the Paleozoic era. The Carboniferous is often split into two divisions, the Mississippian and the Pennsylvanian; in the United States the break in the geologic sequence is so sharp that each division is commonly considered an independent period.
The Lower Carboniferous Period
In the Lower Carboniferous, or Mississippian, period, the submersion : on several occasions : of the interior of North America under shallow seas resulted in the formation of limestone, shale, and sandstone. In the Appalachian region, especially in Pennsylvania, great deposits of sandstone and shale were laid down by the erosion products from the eastern coastal highlands. In the far west the Rocky Mt. region was covered by shallow seas that deposited the Madison and Redwall limestones of the Grand Canyon.
as a period of submergence and great volcanic activity. E of the Rhine, shales, sandstones, and conglomerates were deposited; and in Russia, the Coal Measures formed. The close of the Lower Carboniferous was marked by mountain building in New Brunswick, Nova Scotia, the S Appalachian region, the SW United States, and Europe.
|
