56* FORTYMILE, BIRCH CREEK, AND FAIRBANKS PLACERS, t bull. 251. 
vicinity of the Seventymile. The bed rock at its mouth is a calcare 
ous and graphitic schist, with a strike N. 80° W. and a vertical 
dip. Some work has been done near the mouth. The average depth 
to bed rock is about 8 feet, and the mantle of sand and gravel is about 
2 feet thick. The gravels contain bowlders of schist, conglomerate, 
greenstone, and granite. The gold occurs in thin pieces, which some- 
times have quartz attached. At the time of examination little work 
had been done for five weeks on account of low water. 
Barney Creek. — Barney is a small creek entering Seventymile from 
the north, about 5 miles west of Sonickson Creek and 30 miles north- 
west from Eagle. It is formed by two tributaries, one from the 
north and the other from the east, and flows south about a half mile 
through a very narrow canyon to the Seventymile. The bed rock 
includes closely folded conglomerate and plant-bearing shales, as on 
the Broken Neck. The strike is N. 65° W. and the dip varies from 
55° south to vertical. 
The gravels in the creek are 1J to 3 feet thick, composed of pebbles 
from the conglomerate, pieces of the conglomerate, and bowlders of 
vitreous quartzite up to 3 feet in diameter. The gold occurs in thin 
plates up to one- fourth inch in diameter. 
At a level about 50 feet above the mouth of the creek, on the west 
side of the stream, and also between the forks about one-half mile 
upstream, is a deposit about 6 feet thick on the upturned edges of the 
conglomerate. This deposit consists of 3 feet of gravel and 3 feet of 
sand and muck. The gravels contain large quartzite bowlders, and 
on the point between the creeks have been found to carry gold. 
The fact that similar bench gravels occur on both Broken Neck and 
Barney creeks indicates a considerable distribution of these gravels, 
and the fact that gold has been found in them at Barney Creek points 
to them as a possible source of the placer gold. The quartzite is en- 
tirely massive, vitreous, with no evidence of shearing or schistosity. 
The nearest locality w T here similar rock was found in place is on the 
ridge east of Glacier Mountain and north of Seward Creek. Farther 
west the ridge south of the Seventymile contains many metamorphosed 
quartzose sediments and granular intrusives. No evidence could be 
obtained as to whether gold had ever been found in the conglomerates 
themselves. The creek was first prospected in 1895, and is said to 
have been a good producer in 1896. 
Nugget Creek. — This creek is small, entering the Seventymile 
about 10 miles above Barney Creek. The bed rock is a gneissoid 
granite, and the gravels mostly of the same material, their average 
thickness being about 4 feet. The gold occurs in plates up to one- 
fourth of an inch in diameter, and has garnets associated with it. 
The quantity of black sand is very small. Pay is found over a 
width of 20 feet from rim to rim and for a length of about four 
