BONNIFIELD AND KANTISHNA REGIONS. 221 
id > construct summer trails, as most of the transportation between the 
eeks and the local supply points has been done in winter. 
The auriferous gravels thus far discovered are adapted only for 
immer work when sluicing can be done from about the 1st of June 
> the early part of September, and the rich ground first discovered 
is been largely worked out. There is some ground still remaining 
lat contains fair pay, and about 50 men intended to remain during 
le winter of 1906-7 to prospect. 
(OAL DEPOSITS. 
GENERAL DESCRIPTION. 
Deposits containing lignite coal have a wide distribution in the 
or thern foothills of the Alaska Range, but the only section to be con- 
idered here is that extending east from Cantwell River to Wood 
liver, a distance of about 50 miles, and northward to the flats, 
he low spaces within this area between the east-west ridges of old 
aetamorphic rocks are occupied by these deposits. They are for 
:ie most part but slightly consolidated, and have been so deeply 
ncised by the drainage systems that in places nearly complete sec- 
ions are exposed. That the present areas are only a part of masses 
brmerly much larger in extent is shown by small isolated patches of 
hese deposits that lie slantingly on the upper slopes of ridges and 
>y well-worn pebbles derived from them that lie scattered on the 
;ops of the highest ridges, 1,500 to 2,000 feet above the occurrences 
)f the valleys. These deposits have been folded, the flexures being for 
the most part broadly open, with dips of 30° to 35°, but locally closer, 
with resultant vertical dips attended in places by consolidation of the 
gravel beds to conglomerate; in addition, here and there parts of the 
deposits have been faulted. 
The material comprises alternating beds of sands, clays, coal, and 
gravels that are divisible into three parts — an underlying white deposit 
composed of angular and some well-worn, subangular, fine quartz 
gravels, with a large admixture of kaolinic material where the bed 
rock is feldspathic, an intermediate member of yellowish cross-bedded 
sands and fine well-worn gravels, dark plastic clays, and coal beds, 
and an upper member composed almost entirely of gravels. The 
feldspathic schists produce by weathering a large amount of white 
clay and the quartz veins which in places in these rocks are very 
numerous furnish abundant quartz material, and these characteristics 
of the old bed rock have gone over into the basal members of the 
sediments. The transition from the decomposed products of the 
schists that still retain their structural position to the same materials 
in the overlying deposits is in some places strikingly exhibited. The 
