National Geographic : 1898 Apr
ALASKA AND ITS MINERAL RESOURCES ing rocks. Such conglomerates have been observed in both the Mission creek and Kenai series of beds, and if future study shows them to have been formed under favorable conditions they may prove to be an important source of gold. According to Mr Spurr's observation, the modern placers of Napoleon creek in the Forty mile district, have been enriched by gold derived from the basal conglomerate of the Mission creek series, which is made up of materials derived from the Birch creek, Fortymile, and Ram part series. PROBABLE EXTENT OF GOLD-BEARING DEPOSITS In a new country gold is first sought in the stream gravels, and thence traced up to its source. Very fine gold may be carried long distances by river waters ; hence it is only when it becomes relatively coarse, or at any rate carries coarse particles, that the source may be considered necessarily near at hand. Fine gold is found in almost all the rivers of Alaska, even the silts of the Yukon yield it in places. Gold has been found along the whole length of the Lewes, the Teslin, the Big Salmon, the Pelly, the Stewart, and the Selwyn, and on the Yukon river almost con tinuously from the junction of the Lewes and Pelly downward. Still further east, Frances and Dease rivers, the main branches of Liard river, which flows into the Mackenzie, carry gold. In the Cassiar district, on the Dease river, gold was discovered as early as 1861. The district was actively worked as a placer camp from 1873 to 1887, during which time it yielded about five mil lion dollars' worth of gold dust. These upper regions are dis tant about 1,000 miles in a straight line from the known outcrops of gold-bearing rocks in the Rampart mountains on the Lower Yukon, and are within areas either in which exposures of the gold-bearing rocks as defined above are actually known to exist or in which the similar lithological character of rocks described renders it probable that in some part of the area they may be exposed. There is also some evidence of the extension of rocks of the gold-bearing series to the northwest of the Lower Yukon, though it is as yet impossible to determine whether the primitive gold bearing rocks of the Birch creek and Fortymile series there come to the surface, or whether it is simply the fossil placers or gold bearing conglomerates of later formations, where made up of fragments of these older rocks, that have furnished the gold of modern streams.