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)[1], Bohacs and Suter (1997)[2], and Heckel (2008)[3], 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. (1995)[1] further held that most economic coal deposits developed in domed or raised mires, which excluded 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[4]; Eble et al. 2001[5]; Greb et al. 2002[6], 2003[7]; Neuzil et al. 2005[8]). 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.
Primary Source
References
- ↑ a b Flint, S., J. Aitken, and G. Hampson, 1995, Application of sequence stratigraphy to coal-bearing coastal plain successions: Implications for the UK Coal Measures, in M.K.G. Whateley and D.A. Spears, eds., European coal geology: Geological Society, London, Special Publications 82, p. 1–16.
- ↑ Bohacs, K., and J. Suter, 1997, Sequence stratigraphic distribution of coaly rocks: Fundamental controls and paralic examples: American Association of Petroleum Geologists Bulletin, v. 81, p. 1612–1639.
- ↑ Heckel, P.H., 2008, Pennsylvanian cyclothems in Midcontinent North America as far-field effects of waxing and waning of Gondwana ice sheets, in C.R. Fielding, T.D. Frank, and J.L. Isbell, eds., Resolving the Late Paleozoic Ice Age in time and space: Geological Society of America, Special Paper 441, p. 275–289.
- ↑ Cecil, C.B., R.W. Stanton, S.G., Neuzil, F.T. Dulong, L.F. Ruppert, and B.S. Pierce, 1985, Paleoclimate controls on Late Paleozoic sedimentation and peat formation in the central Appalachian basin: International Journal of Coal Geology, v. 5, p. 195–230.
- ↑ Eble, C.F., S.F. Greb, and D.A. Williams, 2001, The geology and palynology of Lower and Middle Pennsylvanian strata in the Western Kentucky Coal Field: International Journal of Coal Geology, v. 47, p. 189–206.
- ↑ Greb, S.F., C.F. Eble, and D.R. Chesnut, 2002, Comparison of the Eastern and Western Kentucky coal fields (Pennsylvanian), USA—Why are coal distribution patterns and sulfur contents so different in these coal fields?: International Journal of Coal Geology, v. 50, p. 89–118.
- ↑ Greb, S.F., W.M. Andrews, C.F. Eble, W.A. DiMichele, C.B. Cecil, and J.C. Hower, 2003, Desmoinesian coal beds of the Eastern Interior and surrounding basins: The largest tropical peat mires in Earth history: Geological Society of America, Special Paper 370, p. 127–150.
- ↑ Neuzil, S.G., F.T. Dulong, and C.B. Cecil, 2005, Spatial trends in ash yield, selenium, and other selected trace element concentrations in coal beds of the Appalachian Plateau region, U.S.A.: U.S. Geological Survey, Open-File Report, 2005-1330.