Northeastern Section (39th Annual) and Southeastern Section (53rd Annual) Joint Meeting (March 25–27, 2004)
Paper No. 40-14
Presentation Time: 8:00 AM-12:00 PM


CHESNUT, Donald R. Jr, Kentucky Geol Survey, 228 MMRB, University of Kentucky, Lexington, KY 40506-0107,

The Hell For Certain flint clay bed or tonstein is a new name for the flint clay parting of the Fire Clay coal and the coal's lateral equivalents in the central Appalachian basin. The bed has been mapped in Tennessee, Kentucky, Virginia and West Virginia where it was known as "the flint clay parting" or the "jackrock parting" of the coal. The coal name changes from valley-to-valley or county-to-county, but the names are widely recognized to represent the same coal bed and the flint clay, the same flint clay bed. In practice, the bed is a key stratigraphic horizon used in all these states. "Jackrock" is a mining term and refers to the suitability of the hard flint clay as a floor for mining jacks and other roof support systems.

Numerous researchers in the last two decades have reached the consensus that the widespread bed is an altered volcanic ash, most of the ash altering to kaolinite in the mire environment. The suite of included volcanic minerals and the lack of common resistate sedimentary minerals has been used, among other observations, to support a volcanic origin. Sanidine in the tonstein has been dated by several laboratories and all provide an Ar/Ar date of 311-312 ma, the only confirmed radiometric date for Carboniferous strata in the basin.

The Hell For Certain flint clay or tonstein takes its name from Hell For Certain Creek in northern Leslie County, Kentucky. The Fire Clay (Hazard No. 4) coal was extensively mined in this area. The creek is located in the northern part of the Hyden West 7.5-minute Quadrangle. Outcrops have now been overgrown and access is limited, the creek being the only road in many places. A nearby reference section is a roadcut at mile-marker 40 on the Daniel Boone Parkway reported in Cobb et al, 1981. The name Hell For Certain is appropriate because conditions must have been very difficult during the heavy ash fall.

Northeastern Section (39th Annual) and Southeastern Section (53rd Annual) Joint Meeting (March 25–27, 2004)
General Information for this Meeting
Handout (.ppt format, 1035.0 kb)
Session No. 40--Booth# 14
Sedimentation and Stratigraphy I (Posters)
Hilton McLean Tysons Corner: Ballrooms A and B
8:00 AM-12:00 PM, Friday, March 26, 2004

Geological Society of America Abstracts with Programs, Vol. 36, No. 2, p. 89

© Copyright 2004 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.