collier.] CANTWELL RIVER. 45 
blv deposited in an isolated fresh-water basin. No fossils have been 
obtained from these rocks, but they are believed to belong to the 
upper part of the Kenai series or to a younger Tertiary horizon. 
What promises to be workable coal beds were found at two localities 
during the hasty reconnaissance on which these notes are based. The 
most important of these are on Heal} 7 Fork, an easterly tributary of 
Cantwell River, which it joins from the east about 40 miles from the 
Tanana. The coal beds are well exposed in precipitous bluffs along 
the north valley wall of this stream. The strong contrast between 
the white sandstone and the black coal seams makes them very con- 
spicuous features even from a distance. While the beds are largely 
made up of sandstone, yet the layers lying immediately adjacent to 
the coal are most often clay and sandy shales. One bluff about 2 
miles from the Cantwell was examined in some detail. In this section 
200 feet of sandstone and conglomerates formed the basement member, 
and rested unconformable on the phyllites of the metamorphic series. 
This bed was overlain by about 250 feet of soft sandstone shales and 
coal. In the entire section the coal aggregated about 125 feet in 
thickness, contained in about fifteen seams. Of this 125 feet probably 
60 feet were of a fairly good grade of lignite. The largest seams 
were 20 feet in total thickness, but included considerable bone and 
shale. In character the coal varied from a fibrous, impure lignite, 
which is entirely worthless, to lignites which may have commercial 
value. The lignite of better grade is of a lustrous black color, and 
has a conchoidal fracture. The seams w 7 ere accessible only along the 
outcrop, where they were made up of noncoherent lignite. A sample 
taken almost at random from one of the larger seams was analyzed 
by Dr. E. T. Allen, of the United States Geological Survey, with the 
following result: 
Analysis of coal from Healy Fork of Cantwell River. 
Per cent. 
Moisture 13. 02 
Volatile matter 48. 81 
Fixed carbon 32. 40 
Ash 5.77 
100. 00 
Fuel ratio 0. 66 
This analysis shows that the coal is a fairly good lignite. In con- 
sidering it, it should be borne in mind that the short time given to the 
study of the locality makes it quite possible that seams of better grade 
were overlooked. 
The second locality where lignites were found is on Lignite Creek, 
so-called, a few miles north of Healy Fork. At this place the crop- 
pings show fewer seams and these are of less thickness. These lignites, 
as far as determined, were of no higher grade than those of Healy 
