COAL PRODUCTION CYCLE FOR KENTUCKY.
HANEY, Donald C., COBB, James C., and CHESTNUT, Donald, R., Jr., Kentucky
Geological Survey, University of Kentucky, Lexington, KY 40506-0107.

In the 203 years that coal production has been recorded in Kenlucky, aopproximately 6 X 10-9 metric
tons have been produced. The coal production curve for Kentucky resembles half of an idealized
production cycle for an exhaustible natural resource. A production cycle for an exhaustible natural
resource can be summarized in three phases: growth, peak, and decline, and ideally may be
represenled by a bell-shaped curve. The hypothetical production cycle that is based on the Gaussian
distribution function wilh adequate qualifications is useful for predicting future production.
	Kentucky produced 1.5 X 10-8 metric tons of Carboniferous-age coal in 1993, which was
one-third of the coal mined in the eastern U.S. The coal industry in Kentlucky has undergone
significant changes in the past 25 years, as evidenced by the large increase in production and decline
in the number of mines and miners. The current price per ton of coal is nearly the same as it was in
1970, in constant dollars, demonstrating that available resources, competition, and increased
efficiency in the coal industry have produced relatively low-cost coal. If the demand for coal does
not decrease, then how long can the high level of production be maintained? This is essentially a
question about the mineability and recoverability of the remaining resources.
	The original resource of coal greater than 71 cm in thickness in the measured and indicated
classes is 35 X 10-10 metric tons. Production has removed 6 X 10-9 metric tons, and a very rough
estimale of coal left in pillars and barriers is another 6 X 10-9 metric tons. Therefore, approximately
2.3 X 10-10 metric tons of the original resource remains. At current production ratles the next 6 X 10-9
metric tons will be produced in only 38 years. Factors such as mineability, coal quality, technical
and environmental restrictions, and mined-out areas make identifying a reserve base for the next 38
years difficult. Estimates are being made on a 7.5-minute quadrangle basis for the amount of
available and recoverable coal resources in Kentucky. Estimates of the availability of original
resources for mining range from 41 to 71 percent. 0f this remaining coal, the estimates for
recoverability range from only 4 to 26 percent. The Gaussian distribution, estimates of original
resources, availability and recoverability factors, and the production curve appear to predict
declining production in the near future rather than in the distant future.