Influence of a basic intrusion on the vitrinite reflectance and chemistry of the Springfield (No. 5) coal, Harrisburg, Illinois

✍ Scribed by A.K. Stewart; M. Massey; P.L. Padgett; S.M. Rimmer; J.C. Hower

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 574 KB
• Volume: 63
• Category: Article
• ISSN: 0166-5162
• DOI: 10.1016/j.coal.2005.02.005

✦ Synopsis

The Springfield (No.5) coal, a Pennsylvanian-age high volatile B bituminous rank coal in the Carbondale Formation, is mined in the southeastern section of the Illinois Basin. Intruded into this coal is a 10.1-m-wide basic dike that is near vertical through the extent of the mined coal bed, and strikes N 228 W. The intrusion and the effects it had on the coal were studied petrographically and geochemically. Using a published heat flow model by Carslaw and Jaeger (1959) [Carslaw, H.S., Jaeger, J.C., 1959. Conduction of Heats in Solids. Oxford University Press] in conjunction with thinsection microscope analysis, a contact temperature of ~600 8C was determined. Vitrinite reflectance was measured for a suite of coal samples collected distal to the intrusion. Vitrinite reflectance values rose uniformly from the ambient reflectance values of ~0.69%, at just greater than one-dike thickness away, to ~5% at the dike/coal contact. The increase in reflectance values for samples within ~1.2 times dike thickness is concordant with data published by Bostick andPawlewicz (1984) [Bostick, N.H., Pawlewicz, M.J., 1984. Paleotemperatures based on vitrinite reflectance of shales and limestones in igneous dike aureoles in the Upper Cretaceous Pierre shale, Walsenburg, Colorado. In: Woodward,