COAL GEOLOGY INFORMATION: COAL CORE DESCRIPTION AND MINING GEOLOGY

Although coal production is declining in Kentucky and the United States, the need for information concerning coal geology and mining continues. The Kentucky Geological Survey has recently increased the amount of coal information it provides through its web pages. Two new sections include overviews of core description using a three-digit descriptive code, and a coal mining geology section which includes information about seam discontinuities and the geology of roof falls in underground mines.

The core description section includes information about coring, rock properties, the history of the popular Ferm coding system, and a step-by-step walk through the logging method. Step 1 includes pages on major rock types. Step 2 considers aspects of mineral composition and color. Step 3 highlights aspects of bedding, cements, fabric, and pebbles. Quick guides, glossaries, numerical-to-English conversions, and online core books in are included to aid both visitors who are familiar with the system and those who are not. Example images are provided for all rock types, and in many cases, comparisons are made between rocks in core and the same types of rock in outcrop exposures.

The mining geology section describes clay veins, coal balls, coal riders, claystone roofs, concretions, cutouts and rolls (including sandstone, gray shale, and limestone examples), cutout and roll margins, faults, fractures, kettlebottoms, paleoslumps, unusual partings, seam splits, stackrock, weak sandstone, and weak shale. For each of these geologic features, (1) definitions and explanations of formation mechanisms are provided; (2) potential to cause a discontinuity or interruption in a seam are examined; (3) potential roof-fall hazards are discussed; (4) known trends including common geologic facies associations are shown; (5) known occurrences in Kentucky, and in some cases, elsewhere are provided; (6) published methods for planning and mitigation are summarized; and (7) the potential for roof-falls and methods of roof support are summarized. All sections include references to additional information.

The new web pages can be found at www.uky.edu/KGS/coal/ and include hundreds of photographs and diagrams, which should aid researchers, educators, and the general public in better understanding these aspects of coal mining geology.