166 ALASKAN MINERAL RESOURCES TN 1906. 
north, the longest being Noxapaga and Kougarok rivers and Garfiel 
Creek. (See fig. 9.) A number of smaller streams heading in the 
Bendeleben Mountains are confluent from the south, but these ar|| 
outside of the province here discussed. The northern tributaries, 
find their sources in the upland region, through which they meander in j 
valleys which have tortuous courses and whose walls are in many places « 
broken by well-defined benches, many of them covered with gravel. 
Though the topographic features described show no great variety mi 
character of the relief, there is abundant evidence that the physio- 
graphic history of the region was far more complex than this simple 
analysis would indicate. There were no doubt at least two and prob- 
ably more epochs of planation. Moreover, the benches along the< 
valley walls bear evidence that the uplift which brought about the 
incision of the present valleys was intermittent. 
As elsewhere in the peninsula, the dominant vegetation is moss. 
Timber is entirely absent, but thick growths of alder and willow are 
found along the watercourses. Grass, though not abundant, occurs 
in favored localities along the valley floors. The hill slopes are 
usually moss covered, with here and there some grass. Only on the 
highest summits and in sharply cut valleys is bed rock exposed, a> 
feature of the region which makes it exceedingly difficult to decipher 
its geology. ' 
GEOLOGY. 
The stratigraphic units described in the reports referred to — the* 
Kigluaik and the Nome series, including a subordinate member of 
the latter, known as the Port Clarence limestone— are represented im 
the Kougarok region. The limestone, schists, and granites of the< 
Kigluaik series go to make up the Bendeleben Mountains, which 
stretch along the southern margin of the field here described. So far 
as known, these rocks have not been found to he gold bearing and 
ueed no further mention here. 
This older series is separated by a broad belt of alluvium, flooring 
the Kuzitrin Valley, from the schists and limestones of the Nome 
series, which form the country rock of the uplands and are also the 
source of the placer gold. Here the Nome series is clearly divisible 
into two groups — (1) limestone and (2) a succession of graphitic 
phyllites and mica and greenstone schists, with some beds of semi 
crystalline limestone. The schist series is closely folded and faulted 
and its stratigraphic relation to the massive limestone has not bee 
definitely established. Collier's interpretation of the known fac 
leads him to the opinion that the limestone is the younger formation 
while, on the other hand, the writer is inclined to the belief that thj 
schists overlie the limestone. The latter view finds support in tin 
