The
Pennsylvanian is a
geologic (sub)period lasting from roughly 325 million years before the present to 286 million years before the present. As with most older geologic periods, the rock beds that define the start and end are well identified, but the exact date of the start and end of the period are uncertain by a few million years. In
North America where the early
Carboniferous beds are primarily marine limestones, it is treated as a full fledged
geologic period between the
Mississippian and the
Permian. The Pennsylvanian is the upper part of the
Carboniferous in North America. In Europe, the
Mississippian and Pennsylvanian are one more or less continuous sequence of lowland continental deposits and are lumped together as the
Carboniferous Period. Refer to the
Carboniferous Period article for further information on faunal stages and climate.
