120 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bttll. 213. 
earlier channel have been preserved. The only possibility for placer 
mining on a large scale is in the gravels which cover the bed rock of 
the main canyon in its lower extent to a great depth. 
Values. — Values, as a rule, have been good. While some of the 
high-lying patches panned rather low, rich bars were not uncommon. 
Gravel from the bottom of main Bingham Canyon in this same vicinity 
is reported to have brought 18 to 20 cents a yard. The pay levels of 
the West Mountain gravel are said to yield 8 to 10 cents a pan, and 
some of them 6 and 9 and 15 cents a yard. A recent sampling of the 
gravel in the Arganaut cut shows that the lower 30 feet of gravel 
averages 6 cents per cubic yard, and that the lowest G feet averages 
18 cents. 
In general the gold is coarse, varying from half an ounce downward. 
A nugget reported to be the largest ever found in Utah was discov- 
ered in the Clays bar near the mouth of Damphool Gulch by Daniel 
Clays. This is stated to have weighed 17 ounces 15 pennyweight, 
and to have been valued at $128. The fineness is generally considered 
to range from 850 to 875. In round numbers the total known output 
of placer gold from Bingham is about $1,500,000, while the entire 
output would undoubtedly aggregate about $2,000,000. 
( '< >MMEROIAR CONSIDERATIONS. 
Although in the economic work of the Geological Survey "the 
fundamental principle * * * has been that its primary object is 
to determine the general laws which govern the foundation of ore 
deposits," a matters come to notice on which suggestions have been 
given which have frequently proved of immediate commercial value. 
During the progress of the work in Bingham, several points have 
appeared in which it would seem that some improvement would be 
advantageous. It, is hoped to develop some of these suggestions in 
the complete report. At present they may be barely stated. 
The geology of Bingham presents many extremely discouraging 
difficulties. A great thickness of rocks of similar physical character 
and structure have been intruded, crushed, and faulted to a degree 
of complexity which might reasonably have been considered impos- 
sible. Instances are known in which good miners and able experts 
have been thoroughly baffled by this complexity, and so it is not 
strange that mining men familiar with the camp should believe that 
successful mining in Bingham requires, to an unusual degree, thor- 
ough practical geological experience. One familiar with these prob- 
lems appreciates the significance of the common saying among miners, 
that to direct underground work in Bingham successfully one must 
have ' ' grown up with the camp. " 
The irregular porphyry bodies have led to unwise exploration 
through failure to comprehend their origin, and thus their form and 
« Emmons, S.F., Eng. and Min. Jour., Vol. LXXIV, p. 48. 
