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Stratigraphic column showing the units mentioned in the section on channels affecting coal seams other than the Springfield.  +
Isopach map of the Francis Creek Shale.  +
Interpretive cross section of the Herrin Coal, Walshville channel, and Energy Shale.  +
Map showing the Walshville channel and sulfur content of the Herrin Coal. After Treworgy et al. (2000)'"`UNIQ--ref-00000001-QINU`"'. The four named areas of low-sulfur coal are all associated with thick Energy Shale adjacent to the channel.  +
Map showing the Winslow–Henderson channel.  +
Interpretive cross section of the Winslow-Henderson channel. BR, Brereton Limestone; HR, Herrin Coal; BH/BT, Briar Hill/Bucktown Coal; SD/AC, St. David/Alum Cave Limestone; TM, Turner Mine Shale.  +
Disruption of the Danville Coal, with the seam “split” by a thick wedge of mudstone. Note the ragged splaying of coal into mudstone, with a thin coal stringer crossing diagonally from the lower to upper “bench.” The site is the box cut at a portal of the Prosperity Mine in Gibson County, Indiana.  +
Map showing the thickness of the Murphysboro Coal near the Oraville channel in Jackson and Perry Counties, southwestern Illinois. From Jacobson (1983)'"`UNIQ--ref-00000001-QINU`"'  +
Interpretive cross section of the Oraville channel.  +
Stage 1: Deposition of the Delafield Member as a series of coalescing deltas during the onset of a glacial stage as the sea level began to fall. The product is a thick succession of clastic rocks that coarsen upward.  +
Stage 2: Channel incision of delta sediments.  +
Stage 3: The Galatia channel developed a meander belt.  +
Stage 4: The change to a humid climate caused the Springfield peat to begin to form.  +
Stage 5: Springfield peat accumulates across a large area of the basin.  +
Stage 6: A warming climate brought rapid melting of the glaciers and a sea-level rise. The Galatia channel became an estuary, subject to strong tidal currents.  +
Stage 7: Peat swamps drowned as the estuary became an embayment. Dykersburg sediments rapidly buried the peat.  +
Stage 8: As the transgression continued apace, the entire basin area was submerged in deep water, which became stratified and anoxic, and black mud (Turner Mine Shale) was deposited.  +
Stage 9: Normal marine circulation resumed near the apex of an interglacial stage (marine highstand), bringing a brief interlude of carbonate sedimentation (St. David Limestone).  +
Stage 10: Marine regression begins the next cycle.  +
Conceptual model of Pangea during a glacial episode of the Pennsylvanian. From Cecil, C.B., F.T. Dulong, R.R. West, R. Stamm, B. Wardlaw, and N.T. Edgar, 2003b, Climate controls on the stratigraphy of a Middle Pennsylvanian cyclothem in North America, in C.B. Cecil and N.T. Edgar, eds., Climate controls on stratigraphy: SEPM Special Publication 77, p. 151–180. Copyright © 2003, used with permission of SEPM; permission conveyed through Copyright Clearance Center, Inc. ITCZ, intertropical convergence zone.  +