SMARTSVILLE AND VICINITY. 



381 





Mooney Flat there is some uncertainty, and, in the opinion of the captain at the mine, the difference 

 of level between the blacksmith-shop in the mine and the month of the tunnel at Deer Creek is 

 greater than I made it to be with the small aneroid. The error, however, cannot amount to more 

 than a few feet, and it will not affect materially the estimate of grade above given. 



A cross-section of the old gravel channel taken at any point between Smartsville and Timbuctoo 

 would show that the deepest parts are a little to the north of the central line of the deposit, or that 

 the rim on the northern side has on the average a steeper pitch than that on the southern side. 

 The pitch is not uniform on either side, but increases very rapidly as the deepest portion of the 

 channel is approached, which, taken by itself, is comparatively narrow. The diagram (Plate N 

 Fig. 1) is intended to represent a section across the gravel near the line between the old Pactolus 

 and Cement claims. The top of the original gravel hill above the deep channel is reported to have 

 been three hundred feet above bed-rock. 



The bed-rock, where exposed, exhibits many irregularities of grade with high and low places, 

 but nothing that can be called a fault, or that would cause cascades or waterfalls. It is worn into 

 a great variety of fanciful shapes. The depressions are generally from three to six inches deep 

 and are sometimes nearly circular, though more frequently elliptical, oblong, or curved, and ran<dno- 





from two to three feet in length. I did not hear of any deep pot-holes. The bed-rock is for the 

 most part compact and line-grained, changing frequently in appearance, but of a prevailing dark 

 blue color. I thought, at first, that it was probably a highly metamorphosed clay slate, with the 

 schistose characters nearly obliterated.* 



The material of the Smartsville gravel is far from being homogeneous. As a rule the upper 

 strata are reddish or grayish in color, and lighter than the lower, which are usually bluish, at least 

 when first exposed to the air. But there is a very irregular distribution of the layers ; the light 

 and the dark gravels, the clays, sands, and cements being seen to be quite differently arranged 

 even when the faces of banks quite near together are compared. This points to frequent changes 

 in the flow of the old current. The pebbles in the gravel, excluding for the present the volcanic 

 capping, represent a great variety of rocks, pure white quartz being very rare, though not absolutely 

 wanting. It is probable that rock in place corresponding to all the different pebbles could be 

 found at points not far up in the mountains if there were favorable exposures. The faces of the 

 banks which have stood exposed to the air for a few years give remarkable evidences of rapid 

 change. In some of the banks almost every surface pebble could be easily broken, if indeed it 

 were not so soft as to be crushed by the hand. This weathering or "slaking" will facilitate 

 the working of the temporarily abandoned places. Some of the bed-rock also shows si^ns of 

 easy decomposition. A rotten bed-rock is known here by the name of " callous." 



With the liner gravel there occur also many heavy boulders. Even in the upper strata boulders 

 have been met with, smooth on the surface, as if worn by the action of water which are thirty 

 forty, or even as much as sixty feet in the longest diameter. As it does not seem possible that 

 such large blocks of stone can have been brought down by the running stream, I am inclined to 

 think that they had their origin upon the sides of the canon in which the stream was Ho wing. 



At Mooney Flat the top stratum of " white cement " is as much as one hundred and thirty feet 

 thick in places. Under this there is a blue gravel, which contains heavy boulders, such as are not 



€ \ '• J* H J- J- 





unfrequently found along the rim-rock. This is one of the reasons for believing that the deep 

 channel has not yet been struck at this point. 



At the Enterprise bank, below the volcanic capping, of which more presently, there is the 

 ordinary light-colored quartzose gravel, similar to the top gravel in the adjoining mines. The total 

 height of bank here, including the volcanic material, is not far from two hundred and fifty feet. 

 The bed-rock, so far as exposed, is very irregular, and the gravel, particularly on the northwesterly 



* These specimens were examined by Mr. Wadsworth. One taken from the surface of the bed-rock underneath 

 the gravel, near the old Cement claim, proved to be n.elaphyr ; the others, from near the extremity of the new 

 tunnel in the Blue Gravel location, were diabase. Both might, however, have come from the same country-rock, 

 the latter being more crystalline and altered than the former. 



