MINOOK CREEK GROUP. 
29 
the north side of the mouth of Ruby Creek. Other remnants are found on the 
north side of the mouth of Chapman Creek and at a point about 4^ miles above the 
Chapman on the same side of Minook Creek. The last two benches show no gravel. 
On the west side of the creek but few remnants of benches are found. One, about 
50 feet high, extends to a little above the mouth of Hunter Creek, and is probably 
an extension of a corresponding bench on the south side of the Yukon. It seems 
probable that all of the benches of Minook Creek may be more or less closely corre- 
lated with the benches of the Yukon. In the vicinity of the mouth of Slate Creek 
is a bench cut in the upturned slates and thin-bedded quartzites to a depth of 12 to 
16 feet and covered by 4 or 5 feet of gravel and a foot or more of muck. No gravel 
has yet been found upon the benches of intermediate height, but further investiga- 
tion may show its presence. 
In its upper course the creek flows somewhat north of east for about 2 miles, and 
here the topography of its valley is altogether different from that of the lower part. 
The north side is a long, gentle slope with a greater rise in the upper part, while the 
south side is steep and the stream flows near its base. The asymmetry of this part 
of the valley is repeated in Eureka, Pioneer, Hutlina, Omega, New York, California, 
and many other creeks of the region whose valleys lie in parallel or nearly parallel 
directions. 
The rocks in the upper part of the valley are mostly closely folded slates and lime- 
stones. Garnetiferous schists occur at Ruby Creek, and greenstones form the bed 
Fig. 1. — Diagrammatic sketch of Minook Valley. 
rock of the lower valley except near the mouth, where they are partly covered by 
the Kenai rocks. 
The alluvials of the valley are said to be 10 to 12 feet thick and consist of the usual 
muck (soil mixed with much vegetal matter), peaty soil, and gravel, with much 
angular debris at the foot of many of the hillsides. In the middle part of the valley 
they consist of about 5 to 6 feet of muck and the same thickness of gravel. The 
muck thickens toward the sides while the bed rock remains about level. The gravel 
deposits are derived from local bed rock and contain large numbers of smoothly 
rounded quartzite bowlders from a few inches to 3 feet in diameter, whose source has 
been a mystery to many. Some of these bowlders have undoubtedly descended to 
the present creek bed from the high benches already referred to, in whose gravels 
they are abundant. 
The outcrop of quartzite near the " 72 road house " would in itself seem sufficient 
explanation for the bowlders below, but above this point the thinner quartzite beds 
have added many more to the stream. The quartzites are so hard and their abrasion 
is so slow that while the other rocks wear into sand and small pebbles, or decompose 
and are swept away, the quartzite bowlders remain and make up a continually 
larger proportion of the gravels. 
Mining. — Minook Creek has not produced a large amount of gold. The wide 
valley, large stream, and heavy gravels have made mining difficult, so that men 
