Galatia Channel:Peat Developed at Lowstand
Peat Developed at Lowstand
Our model calls for the Springfield Coal (and, by implication, other Pennsylvanian coal seams) to be formed during eustatic lowstand under ever-wet conditions. Some previous authors, such as Flint et al. (1995), Bohacs and Suter (1997), and Heckel (2008), maintained that peat developed during transgression. According to their view, preserving a thick peat deposit requires a rising water table because otherwise peat is oxidized and lost. Flint et al. further held that most economic coal deposits developed in domed or raised mires, which exclude clastic sediment derived from nearby rivers.
However, evidence from coal-body geometry, coal petrography, geochemistry of coal and enclosing strata, and fossil-plant patterns strongly suggests that Desmoinesian coal in the Illinois Basin developed as planar, not domed, peat deposits (Cecil et al. 1985; Eble et al. 2001; Greb et al. 2002, 2003; Neuzil et al. 2005). Thus, peat accumulated at grade with the Galatia channel, with plants filtering clastics through the flanking belts now preserved as shaly coal. The Galatia was a river without banks or natural levees. Perennial flooding from the channel, coupled with an ever-wet climate, ongoing basin subsidence, and ongoing compaction of underlying sediment, maintained a consistently high water table throughout the duration of Springfield peat accumulation.
W. John Nelson, Scott D. Elrick, William A. DiMichele, and Philip R. Ames xxxx, Evolution of a Peat-Contemporaneous Channel: The Galatia Channel, Middle Pennsylvanian, of the Illinois Basin FINISH CITATION