This coal-forming period of geologic time is split into Mississippian & Pennsylvanian periods
..... Late in the Devonian Period and continuing into the Mississippian 
Period,... [DOC] [TLE] Carboniferous Period: Overview [Uploaded 100306] - Timism [PAR] The Carboniferous Period occurred from about 354 to 290 million years ago 
during the ... into the Mississippian (Lower Carboniferous) and the 
Pennsylvanian (Upper ... the Carboniferous Period witnessed periods of 
significant ice cap formation over ... Earth's climate and atmosphere have varied 
greatly over geologic time.