GEOLOGICAL SURVEY OF THE TERRITORIES. 107 



tlie particles of quartz in this granite which points to a mechanical 

 origin. The rock is quite uniform in its structure. A mile or two in 

 the caQon we came to a small village called Graniteville. It is near 

 here that the granite, of which the Mormon temple is being built, is 

 quarried. Instead of working into the rock on the sides of the canon, 

 the quarrying is confined to the huge blocks of granite which are scat- 

 tered over the bottom on both sides of the creek. Some of these blocks 

 are immense, measuring 30 feet square. They aresplitinto the required 

 size. Our road for about five miles leads us between the granite walls 

 that tower far above us, surmounted by dome-like masses, whose summits 

 are covered with snow, giving origin to the numerous falls and cascades 

 which abound on the sides of the canon. The Little Cottonwood Creek 

 flowing i^ast us falls about 500 feet to the mile. It rushes along furiously 

 over its rocky bed, seeming to be at war with the immense bowlders that 

 dispute its right of way. As we proceed we leave the granites behind 

 us, and above us project the sharp, jagged edges of quartzite beds. 

 These quartzites have a reddish color, and are followed by slates upon 

 which rest thick beds of white limestone. The lower beds are crystalline 

 and probably Silurian, although I was unable to find any fossils in them. 

 The upper layers are dolomitic, and are Carboniferous in age. It is in 

 these limestones that the ores occur. The principal mine is the Emma. 

 Unfortunately, owing to a disturbance at the time of our visit, I was 

 unable to see tbe Emma mine, but visited the Flagstaff and the Silver 

 Star. I quote the following analysis and remarks ujion the ore of the 

 Emma mine from an article by Professor Silliman:* 



I am able to preseut an analysis of an average sample of 82 tons (=183,080 pounds) 

 of first-class ore from the Emma' mine, made by James P. Merry, of Swansea, April, 

 1871, which is as follows : 



Per cent. 



Silica 40.00 



Lead 34.14 



Sulphur 2. 37 



Antimony 2. 27 



Copper 0. 83 



Zinc 2.92 



Manganese 0. 15 



Iron 3. 54 



Silver 0.48 



Alumina 0. 35 



Magnesia 0. 25 



Lime ^ 0. 72 



Carbonic acid 1.50 



90. 42 

 Oxygen and water by difference ^ 9.58 



100. 00 



The quantity of silver obtained from this lot was 156 troy ounces to the gross ton of 

 2,240 pounds. 



This analysis sheds important light on the chemical history of this remarkable 

 metallic deposit, and ■\^fll aid us in the study of the paragencsis of the derived species; 

 It is pretty certain that all the heavy metals have existed originally as sulphides, aud 

 we may, therefore, state the analysis thus, allowing 8.52 per cent, sulphur to convert 

 the heavy metals to this state: 



Silica 40.90 



Metallic sulphides 52.60 



Al, .35,Mg, .25;Ca, .72; Mu- Jsin, .20 1.52 



95. 02 

 Water, carbonic acid, and loss , .' 4. 95 



^American Journal of Science and Arts, vol. iii, page 198. 



