Results of our investigation of foot-by-foot sections from drill cores of two North Slope coals of Cretaceous age from Cape Beaufort and Kukpowruk River indicate drastic changes in environment during formation of the seams. Indicative of these changes are unusually wide variations in the petrographic composition and ash characteristics within the seam. For instance, the Kukpowruk samples showed an increase in semi-fusinite from 1.3% at the bottom to 32% at the top. Furthermore, the concentrations of Fe₂O₃ + CaO + MgO in the Kukpowruk seam ranged from a low of 7.2% to a high of 80.9%. Similar changes were found in the samples from Cape Beaufort.

The variability in these coals was further identified by changes in the swelling behavior of the coal and to a lesser extent by rank characterization. Changes in the coal structure and its low temperature ash were also studied by means of Fourier transform infrared spectroscopy.

End_of_Article - Last_Page 683------------