Gold in Placers.— Wood. 375 
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into the Missouri, the detritus and wash from the gulch extends 
out in a broad fan-shaped sloping terrace for two or three miles. 
The gold is disseminated to a greater or less extent throughout 
the whole of this bed, but only in workable quantities in certain 
localities noticeable at the immediate entrance to the gulch. As we 
proceed up the gulch the gold bearing’ strata gradually sink to a 
depth of 60 feet or more, to which shafts have been sunk to the 
gold bearing zone, ‘Towards the head of the gulch which is six 
or seven miles in length the gold belt rises till it merges on the 
surface and at the extreme head of the gulch splits into finger- 
like streams which have been traced to the veins in situ from 
which the gold came, 
Fig. 1 represents a longitudinal section of the gulch, in which 
the dots show the deposition of the gold in the detritus gravels 
from the mountains. A A Aare veins, B the exit and fan-shaped 
— Seven Miles — 
bed of gravels, C the surface line of detritus, D the line of de- 
position of gold. The veins consist of one very large vein of 
nearly pure iron pyrites, associated with some quartz as a gangue, 
It is about forty feet in width, and has been mined to a depth of 
90 feet, to which depth the pyrites was decomposed into oxides of 
iron. 
In the vicinity of this vein are numerous small veins of a few 
inches in width up to which the gold streaks lead in the gravels. 
The country rock is an eruptive trap-like rock. At the head of 
the gulch near the veins the large nuggets were obtained. This 
is easily explained by the great weight of these large nuggets, 
which are deposited first as the detritus was laid down by the 
running water. The veins vary in their direction, one vein pene- 
trating the east side of the gulch for 1,500 feet, and being 
enly two or three inches in width, assaying $2 to the ton. As to 
