i mil I i: 
DEEW MINE. 37 
in a sandstone series which, from its fossil plant remains, has been 
assigned to the Kenai. These beds are found in a small area near the 
town of Rampart, where they are over 5,000 feet thick and rest 
uneon formably on indurated cherts and tuff's belonging to the Ram- 
part (Devonian) series. Some of the beds are compact sandstones and 
conglomerates, while others are almost unconsolidated. Several other 
small areas of Kenai beds have been found in this part of the Yukon 
Valley, as is indicated on the map, PI. II. An unsuccessful attempt 
has been made at mining a lignite seam which occurs in unconsolidated 
beds that contain Pleistocene fossils. 
Drew mine. — The Drew mine is situated on the left bank of the 
Yukon, 25 miles above Rampart and opposite the mouth of Hess 
Creek. It is probably the oldest coal mine on the Yukon, and has 
been known, at different times, as the Miller mine and the Pioneer 
mine. It is the only coal mine that has been operated in the Rampart 
province, and there are no promising deposits of coal known along the 
main river within 300 miles either above or below it, so that it is 
probably the most important point for coal mining on the Yukon. A 
view of this mine, as it is seen from the river, is shown in PI. V, A. 
The coal-bearing formation at this place is confined to a great bend 
of the Yukon, and its known extent is not over 4 square miles. (See 
fig. 3.) Opposite the Drew mine the banks of the Yukon are low, 
and a broad flood plain extends for several miles up the valley of Hess 
Creek. The coal-bearing sandstones are probably continued beneath 
these flood-plain deposits, and may be connected with the coal-bearing 
formations exposed near Rampart, which have been described. 
From Fort Hamlin to within a mile of this mine the Yukon flows 
in a canyon cut in a system of diabases and tuffs interbedded with 
the more or less cherty slates of the Rampart series. One mile above 
the Drew mine the rocks of the Rampart series are succeeded \>y a 
great thickness of sandstones, carrying fossil plants which have been 
referred to the Kenai series. Near the point of contact of these for- 
mations the Rampart rocks are hard, siliceous slates, with interbedded 
tuffs, striking N. 30° E. and dipping southeast at an angle of 70°, but 
the immediate contact is not exposed. The strike and dip of the sand- 
stones appear to agree with those of the slates. Sandstone beds stand 
at a high angle, dipping away from the underlying rocks. From this 
point to the coal mine, a distance of 1 mile, there are frequent though 
not continuous exposures of sandstone standing at high angles. At 
the coal mine the sandstones are nearly vertical. If there is no close 
folding or faulting, with consequent repetition of these beds, their 
thickness should exceed 5,000 feet. The areal distribution and strati- 
graphic relations are shown in the sketch map and section, fig. 3. 
In the lower 4,000 feet of this section no coal seams have yet been 
found. This portion is made up of fine-grained sandstones and shales 
