FAIRBANKS AND RAMPAKT QUADRANGLES. 29 
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ECONOMIC GEOLOGY. 
FAIRBANKS REGION. 
(JEN ERAL STATE M EN T. 
The Fairbanks region includes the gold placers of the Xanana 
Valley about 2(>0 miles above the mouth of the river. They comprise 
parts of the valle} 7 s of small streams, most of which are within 25 
miles of the navigable water of the Tanana. The location of a trad- 
ing post in this part of the Tanana Valley in 1901 was followed in 
1902 by the discovery of gold. The region began to attract attention 
and by the end of 1903, with a production of at least $40,000. had be- 
come of prospective importance. The work of 1904 resulted in a 
production. of about $000,000. which was increased in 1905 to about 
$0,000,000, and in 1906 to over $9,000,000. 
The Fairbanks region was visited by A. H. Brooks a in 1900 and 
1907, and the condition of the creeks is thus described by him : 
Cleary, Fairbanks, Dome, Vault, Esther, Coldstream, and Pedro creeks and 
their tributaries are the chief producing creeks of the district. Cleary continues 
to stand first in production, with Fairbanks in second place. The finding of 
values on Cripple and Treasure creeks definitely extends the producing area 
to the southwest, and reported discoveries of gold in the upper Chena may show 
a northeasterly extension of the same belt, though this is not yet established. 
The facts in hand are, however, sufficient to determine that there is a gold 
bearing zone, at least 10 miles wide, running northeast and southwest, which 
has been traced for about 30 miles. Its northeastern extension would intersect 
the upper Chena basin, while to the southwest it runs out into Tolovana tlats. 
A logical deduction from these facts would suggest that the prospector could 
turn his attention to the Chena basin and to the streams draining the upland 
which bounds the Tolovana fiats on the east. It should be remembered, how- 
ever, that the investigations so far made indicate that the conditions which 
bring about mineralization are local, and hence the formation of placers proba- 
bly does not persist over any great distance. 
Worthy of special note are the rich placers found last year on Vault ('reck. 
which had previously been unproductive. On nearly nil the producing streams 
which are tributary to the Chatanika the pay streak' has been traced wed down 
to the main river. In fact, the origin of the rich gravels found in various 
places at inn to 200 feet depth under the vallev floor of the Chatanika is among 
the most puzzling of the phenomena connected with the placers of this district. 
Interest in Goldstreani ('reek was revived during last summer by some rich 
placer discoveries, and as a result, though the creek was alniosl abandoned in 
the early part of the summer, later it was studded with operators for several 
miles. 
Of the outlying districts tributary to Fairbanks the Tenderfoot probably 
made the largest production, estimated at $300,000. The gravels on Tender- 
foot Creek are deep, but in the smaller -reeks are said not to exc l S to L0 
feet in depth. It would appear thai these deposits lie in a different /.one from 
those of Fairbanks. 
"Brooks, A. IT., report on progress of investigations of mineral resources of Alaska, 
I'.mh;: Pull. r. s, Ceol. Survey .\... ;;ih 1907, pp. 36-37, 
