THE BRANDY CITY AND EUREKA RIDGE 



463 



It is a favorite idea with many of the miners that there is an old gravel channel underlying the 

 volcanic capping between Brandy City and Eureka, and the claim is made that the ridge has 

 " never been half prospected." I was told, however, of several tunnels that had been driven at 

 different points, both on the Canon Creek and on the Fiddle Creek side of the ridge, in which 

 gravel was found, but in which, for some good reason or other, further operations had to be 

 suspended. I did not have time to examine the ridge in detail, but from all that I could see or 

 learn, I am led to the conclusion that no continuous channel exists there. 



The gravel deposits at Eureka and Mugginsville cross the ridge at a gap where the volcanic cap- 

 ping has been almost entirely removed ; and, were it not for the cap at Chaparral Hill, it would 

 be easy to believe that the gravel channel is of more recent origin than the lava-flow. The dia- 

 gram (Plato V, Fig. 2), representing a section across the Eureka gravel from northeast to south- 

 west, gives the general features of the topography as they were sketched by me at the time of my 

 visit ; there was no time for detailed measurements of altitudes and distances. My observations 

 for altitude in this vicinity were made under unfavorable conditions ; for I had to depend upon 

 the small aneroid alone, without any opportunity for comparison with the mercurial barometer, for 

 an interval of more than thirty-six hours. I cannot tell how great the probable error is, but there 

 is good reason for believing that my results are all too high. I am led to this conclusion by a 

 comparison of the values obtained for the altitudes of Craig's Mat and Monte Cristo, places whose 

 relative heights I was able to ascertain by observations with the hand-level. 



The town of Eureka, built originally directly upon the gravel, comprises now only a few houses, 

 and these are doomed to speedy destruction if hydraulic mining is pushed any further. The alti- 

 tude of Wolfe's Hotel I made to be 5,138 feet. The gravel extends in an unbroken mass, Mug- 

 ginsville being separated from Eureka only by the narrow water-course of Eureka Creek, in a 

 southeasterly direction for more than a mile, and with an average width of fully one thousand feet. 

 The bed-rock has been uncovered over a large part of this area, but there is still a very large body 

 of gravel left to move. 



In the Eureka mines the clean quartz gravel, carrying a little clay or sand near the bed-rock, is 

 nearly seventy feet in thickness. Above this there is a heavy deposit of pipe-clay, which in places 

 is as much as fifty feet thick. At Mugginsville the gravel has been removed from a semi-circular 

 opening, five or six acres in extent, on the northwestern slope of Chaparral Hill. The altitude of 



the bed-rock I made to be 5,090 feet, which is undoubtedly too high. The bed-rock is slate, and 

 has the usual north westerly strike and vertical dip. The most of it is yellow in color, and is quite 

 soft for at least forty feet in depth. There is also some banded clay, a few feet in thickness, 

 looking like decomposed bed-rock, and similar to that previously described as occurring at Plug 

 Ugly Hill and at Secret Diggings. The highest bank is nearly two hundred feet in height, and 

 consists of twenty-five feet of gravel at bottom, covered by pipe-clay, which in places is as much as 

 thirty feet in thickness, fifteen feet of a liner sandy gravel, twenty feet of clay and loam, and a 

 hundred feet of a very easily moved volcanic dirt. About one half of the quartz pebbles are bluish 

 in color. They are also considerably coarser than the pebbles at La Porte or Morristown. Large, 

 worn boulders are also found in abundance. There is some petrified wood in the gravel, but there 

 are no impressions of leaves and no animal remains. The gold is coarse and like shot, and, accord- 

 ing to the statement of Mr. W. A. Morse, lias a fineness of .930-. 934. A small fault of about 

 eight inches was observed in the face of the bank, where the break in the strata of differently 

 colored clays made it easy to detect the slight movement. 



• The altitude of the top of Chaparral Hill I made to be 5,275 feet. According to the hand-level 

 observation, this should be the same as that of a point near the base of the bank at Monte Cristo, 

 on the opposite side of Goodyear Creek. The hydraulic banks on the southeastern slope of the 

 hill I did not have time to visit. I went as far as the mouth of Hardee's tunnel, where I deter- 

 mined the altitude to be 5,038 feet. The course of this tunnel is S. 45° W. (magnetic) for 400 

 feet, and then more westerly for 200 feet farther. The rise in the tunnel is two inches in twelve 

 feet for 300 feet, and for the rest of the way ten inches to twelve feet. Cravel lies about twelve 



