6 ALASKAN MINERAL RESOURCES IN 1905. 
As will be shown below, the gold-bearing terranes of southeastern Alaska are made up 
of metamorphic rocks, chiefly of Permian age; those of the Yukon are of undetermined, 
probably Lower Paleozoic age, while the terranes of Seward Peninsula find place in the 
Silurian or in older sediments. In all these districts there appears to be a rather intimate 
connection between the occurrence of the quartz veins, whence the gold has been derived, 
and the intrusives. If the very incomplete data should permit one to venture an opinion, 
it would be that the period of mineralization in both the coastal and the Yukon provinces 
occurred during Lower Cretaceous time. In Seward Peninsula the mineralization may 
have taken place at a later date. The copper deposits of the Mount Wrangell region, 
associated with rocks of Permian age, appear to be the result of a distinct type of mineral- 
ization not yet found elsewhere in Alaska. 
Coal-bearing strata, chiefly of Eocene or Oligocene age, find a wide distribution through- 
out Alaska. Both Carboniferous and Jurassic coal measures have been found at Cape Lis- 
burne. The most extensive coal fields of the Territory probably lie in the Arctic slope 
region, but those of the Pacific seaboard and the Yukon River basin are of the most import- 
ance. The high-grade bituminous coals of the Controller Bay region and of the Matanuska 
Valley, described elsewhere in this bulletin, are at present of the most commercial import- 
ance. Good coal has also been found in the Alaska Peninsula, but the extent of the deposits 
has not been determined. 
AURIFEROUS LODE MINING. 
Southeastern Alaska continues to be the only important district of lode mining in the Ter- 
ritory, but considerable prospecting has been done in other fields. The Panhandle, with its 
strong relief, abundant water power and timber, accessibility, and salubrious climate is 
undoubtedly the ideal mining region of Alaska and compares favorably with any other on 
the continent. The success of the famous Treadwell group of mines is an example of what 
can be accomplished in this field under scientific management. This great enterprise, 
though a magnificent object lesson, has dwarfed other important plants in the same field. 
It has also led to the inauguration of a number of unsuccessful ventures, because promoters 
have been only too ready to designate every low-grade ore body as "another Treadwell." 
The auriferous lode mining of this part of Alaska is fully described by F. E. Wright and 
C. W. Wright on pages 30-54. 
Westward from the Panhandle there is no lode mining until Prince William Sound is 
reached. The copper deposits of this district are described by Mr. Grant (see p. 78). 
These ore bodies carry more or less gold, and hence deserve a passing mention here. The 
Kenai Peninsula has been the scene of considerable prospecting for quartz during the past 
year. Some encouraging results are reported near the line of the Alaska Central Railway 
and also at Port Dick and Port Chatham, near the extreme south end of the peninsula. 
Copper- and gold-bearing lodes have also been found on the west side of Cook Inlet, near 
Iliamna Bay, but their commercial importance remains to be proved. 
Kodiak Island has been the scene of prospecting for quite a number of years, but so far 
no extensive ore bodies have been found there. Mr. Paige, who visited some points on this 
island during the past summer, reports that the bed rock consists primarily of slates and 
sandstones, with some conglomerate. The entire rock series is closely folded and jointed and 
is cut by an intricate system of quartz stringers. These stringers, in some cases, are large 
enough to be called veins and carry some sulphides and are probably the source of the 
beach gold which has been mined at several localities. A five-stamp mill has been at work 
at Uyak Bay, on the west side of the island, for several years. In the extreme southwest- 
ern portion of Alaska lode mining is on the decline, for the Apollo Consolidated mine, which 
has been operated on Unga Island for many years, has been closed down. 
The Yukon region, though it continues to be the scene of extensive gold-placer discov- 
eries, so far has not yielded any auriferous lodes. The same holds true in Seward Peninsula , 
where, with the exception of the Big Hurrah quartz mine, no lode deposits have been devel- 
oped. It is to be said for both these fields, however, that but little attention has thus far 
