COLLINS, STEVEN L., University of North Carolina, Chapel Hill, NC

ABSTRACT: Relative Trace-Element Concern Indexes for Eastern Kentucky Coals

Coal trace elements that could affect environmental quality were studied in 372 samples (collected and analyzed by the Kentucky Geological Survey and the United States Geological Survey) from 36 coal beds in eastern Kentucky.

Relative trace-element concern indexes are defined as the weighted sum of standardized (subtract mean; divide by standard deviation) concentrations. Index R is calculated from uranium and thorium, index 1 from elements of minor concern (antimony, barium, bromine, chlorine, cobalt, lithium, manganese, sodium, and strontium), index 2 from elements of moderate concern (chromium, copper, fluorine, nickel, vanadium, and zinc), and index 4 from elements of greatest concern (arsenic, boron, cadmium, lead, mercury, molybdenum, and selenium). Numerals indicate weights, except that index R is weighted by 1, and index 124 is the unweighted sum of indexes 1, 2, and 4.

Contour mapping indexes is valid because all indexes have nonnugget effect variograms. Index 124 is low west of Lee and Bell counties, and in Pike County. Index 124 is high in the area bounded by Boyd, Menifee, Knott, and Martin counties and in Owsley, Clay, and Leslie counties. Coal from some areas of eastern Kentucky is less likely to cause environmental problems than that from other areas.

Positive correlations of all indexes with the centered log ratios of ash, and negative correlations with centered log ratios of carbon, hydrogen, nitrogen, oxygen, and sulfur indicate that trace elements of concern are predominantly associated with ash. Beneficiation probably would reduce indexes significantly.

AAPG Search and Discovery Article #90995©1993 AAPG Eastern Section Meeting, Williamsburg, Virginia, September 19-21, 1993.