PLACERS OF THE RAMPART REGION. 97 
placers of the region probably belong to the first class, although 
there may be some reconcentrated gold in Thanksgiving and Quail 
creeks. 
The gold of the .reconcentrated placers is generally smoother and 
brighter than that from the others, contains less quartz and iron, owing 
to abrasion and oxidation, and is thus higher in value per ounce, 
though the higher value of the gold of the Minook group is princi- 
pally due to its containing less silver than the gold of other creeks. 
There is much crystallization in the gold, particularly of the Baker 
Creek group, where the gold contains a large percentage of silver. 
It is notable that along Minook Creek, where the gold contains so 
little silver, native silver nuggets are found in the placers, while in 
the Baker Creek group, where the placer gold contains about 20 per 
cent of combined silver, there are no silver nuggets. The only other 
minerals known in the concentrates with the gold are hematite, a 
small amount of magnetite on Thanksgiving Creek, pyrite, garnets 
on Ruby Creek, barite on a few other creeks, and copper on Hunter, 
Little Minook, and Slate creeks. 
In all cases the origin of the gold has probably been in the imme- 
diate neighborhood of the placers, though it may be the result of the 
concentration of many hundreds of feet of bed rock. There seems 
to be no indication that the gold has been derived from any great 
" mother lode," and it has probably come from comparatively small 
veins distributed through the country rock. 
All of the creeks at present known to be gold bearing to a paying 
extent, except Slate and Ruby creeks, take their rise in the Minook- 
Baker-Troublesome divide. Along this divide are dikes of monzo- 
nitic, dioritic, and acid igneous rocks, and it may be that these were 
associated with causes that introduced gold-bearing solutions into 
the rocks. The large mass of diabasic rocks in the Minook group 
may have been related in some way with the mineralization of that 
area. 
As to the origin of the silver and copper nuggets with the gold in 
the creeks of the Minook group, little can be said. On all the creeks 
hi which they are found, except Slate Creek, both limestones and 
diabases occur. On Slate Creek diabase was not seen, although there 
is much of it on Ruby Creek. It is likely that the silver and copper 
nuggets come from the oxidation of contact minerals resulting from 
the diabasic intrusions. 
The average depth of gravel worked is probably between 10 and 20 
feet. The gravels are mostly frozen, but much trouble in working 
them is sometimes had on account of live water. Hydraulicking has 
been introduced and apparently works well in the frozen gravels. 
This form of mining will probably become of considerable importance 
24304— Bull. 337— OS 7 
