The Carboniferous Geological Period
 360 to 285 Million Years Ago

The Carboniferous Period occurred from about 360 to 285 million years ago during the late Paleozoic Era. The  term "Carboniferous" comes from England, in reference to the rich deposits of coal that occur there. These  deposits of coal occur throughout northern Europe, Asia, and midwestern and eastern North America.

The term "Carbonif- erous" is used throughout the world to describe this geological period, although this period has been separated into the Mississippi (Lower Carboniferous) 360 to 325 million years ago, and the Pennsylvanian (Upper Carboniferous) 325 to 285 million years ago, in the  United States. This system was adopted to distinguish the coal bearing layers of the Pennsylvanian from the  mostly limestone Mississippi, and is a result of differing stratography on the different continents.

The picture above represents what a majority of the land mass of  the world looked like 300 million years ago. For more information, click on the picture.

illustration from the web pages of Dr. Ronald Blakey, Professor of Geology, Northern Arizona University.


Information from the University of California, Museum of Paleontology
Carboniferous : Stratigraphy
The stratography of the Lower Carboniferous (Mississippian Period) can be easily distinguished from that of the Upper Carboniferous ( Pennsylvanian Period). The environment of the Mississippi period in North America was heavily marine, when seas covered parts of the continents. As a result, most of the mineral found  in the Mississippi is limestone, which are composed of the remains of crinoids, lime encrusted green algae,  or calcium carbonate shaped by waves. 

The North American Pennsylvanian environment was alternately terrestrial and marine, with the transgression and regression of the seas caused by glaciation. These environmental conditions, with the vast amount of plant material provided by the extensive coal forests, allowed for the production of coal. Plant material did not decay when the seas covered them and pressure and heat eventually built up over the millions of years to transform the plant material to coal.

The amount of land exposed to the air increased during the Carboniferous. This increase is probably due to plate tectonics and to the thickening of the crust. This trend towards increasing elevation of land masses can be seen by the different types of rock deposits that are found in different locations. The Mississippi period is marked by marine deposits leading to the conclusion that shallow seas covered large areas, but by the Pennsylvanian Period, there was an uneven but progressive trend towards elevation of land masses and marginal marine and continental environments became dominant.

The restriction of oceans to the margins of the continents and the fluctuating sea levels led to the unconformity of the strata associated with the Carboniferous period. These changes to a less marine environment led to the terrestrial radiation of animals that started during the Carboniferous. Terrestrial radiation also occurred because of drying trends that were the result of large glaciers, most of which originated in the South Pole of the time. 

Source: Eicher, Don L & A. Lee McAlester. 1980. History of the Earth. 
Prentice Hall Inc.

Information from The University of California, Berkeley, Museum Of Paleontology.
 
A large amount of the technical information presented on this and other pages was borrowed from 

PAGE LAST UPDATED: MARCH 3, 2002