172 ALASKAN MINERAL RESOURCES IN 1906. 
This amount is, however, only an approximation. It should be 
noted that this does not include the output of the entire Kougarok 
precinct, but only that part of the precinct which is described in this 
paper. The production of 1906 a was very small, owing to the lack of 
water. 
DISTRIBUTION OF AURIFEROUS GRAVELS. 
To speak broadly, the auriferous gravels thus far discovered in the 
district fall into two zones which converge from lower Kougarok 
River. (See map, fig. 9, p. 165.) The larger zone, here termed the 
"Koug-arok belt," stretches northward and embraces much of the 
Kougarok basin; the smaller zone, which appears less well defined, 
extends eastward to the Noxapaga, embracing the streams tributary 
to Kuzitrin River. This second zone will here be called the " southern 
belt." The Kougarok belt lies in a zone of schistose rocks, bounded 
on either side by the massive limestones. It furnishes, therefore] 
further evidence for the general law that the gold has its source at or 
near the limestone and schist contacts. Nor does the southern belt, 
so far as known, offer an exception to this rule. Each of these two 
belts embraces placers of the various types to be described below. 
SOUTHERN BELT. 
GENERAL DESCRIPTION. 
The auriferous gravels forming a broken fringe along the southern 
margin of the highlands which bound the Kuzitrin basin on the north 
and west have certain features in common which justify the descrip- 
tion of them as a unit. This belt includes the placers of Quartz and 
Garfield creeks, as well as those of the Noxapaga basin. 
The bed-rock geology of this belt is obscured, both by the extensive 
alluvial deposits and by the products of deep rock decay. It appears 
however, that a belt of graphitic phyllites and schists, including some 
calcareous matter, stretches across the upland lying between Kaviruk 
and Kuzitrin rivers. In many places these rocks carry quartz veins, 
some of which arc stained wil h mica and quartz. Schists occur north 
of the graphitic rocks, and still farther north these give way to a lime- 
stone. Though it is impossible to delineate these formations exactly 
because of the deeply weal hered character of the rocks and the absence 
of outcrops, yet it appears that most of the gold-bearing creeks cross 
the contact of the limestone and schist. 
The unconsolidated formations embrace (1) the present stream 
gravels, (2) the deposits flooring the Kuzitrin lowland, and (3) the 
bench gravels. Of the first group, which embraces most of the Work- 
er Not a single operator in the district responded to a requesl for information in reference to pro- 
duction. 
