In other places the rock is solid and smooth in its lower
portion, and only scaly and scragly in its upper parts, yet
always presenting a type, or idiosyncrasy of structure that
could be very readily recognized, and the seam traced with-
out difliculty. It extends throughout the upper half of the
Blackburn Fork basin, and is found in the Locust Fork
basin, and probably extends through the divide between
them. Towards the western end of the Blackburn Fork
basin, this seam either becomes small and insignificant or is
divided into two seams. Near the western side of S. 20, T.
13, R. 2 R, the characteristic cap-rock of this seam is found
about 40 feet above Seam No. No, 20, with a thin six inch
seam of poor coal beneath it This is at least 20 feet below



THE BLOUNT MOUNTAIN COAL FIELD. 51

its normal position, and more than 80 feet below the Woodward
Seam next above it, yet no evidence of an intervening seam
was found between them, where the upper member of the
Armstrong Seam properly belonged. It is probable that
this seam either divides or terminates near this place. It
was not traced or recognized southwest of the range line
between ranges 1 and 2 east.
