LEAD AND SILVER. 189 



BRUNTON. 

 Archaean. 



1. Cambrian quartzite, 400 feet. 



2. Silurian quartzite and limestone, 460 feet. 



3. Lower Carboniferous dolomite, 225 feet. 



4. Lower Carboniferous blue limestone, 110 feet. 



5. Middle Carboniferous (Weber) shales, 50 to 450 feet. 



6. Intruded diorite, maximum 400 feet. 



7. Middle Carboniferous limestone, 10 to 160 feet. 



8. Jura-Trias sandstone. 



E M M o N s . 

 Archaean. 



1. White quartzite of Upper Cambrian, 200 feet. 



2. Silurian limestone and sandstone, 340 feet. 



3. Lower Carboniferous brown and blue limestone, 240 feet. 



4. Middle Carboniferous clays (Weber shales), 425 feet. 



5. Middle Carboniferous green and red sandstone, of the 

 Weber grits, with thin limestone. 



6. Jura-Trias sandstone. 



2.08.13. Two other sections by different writers (Lakes and 

 Henrich) have been published; but as fossils are almost unknown, 

 the strata can be divided more or less at will. The blue lime- 

 stone is certainly Lower Carboniferous, for fossils gathered by 

 J. F. Kemp from the same horizon on Lime Creek, twenty-five 

 miles north, where they are plentiful, were pronounced by authori- 

 ties in the East to be such. 



2.08.14. On Smuggler Mountain the same section is shown, 

 but it is not broken by igneous rocks; and although there is a 

 faulting along planes striking parallel with the beds and cutting 

 the dip at a sharp angle, the geology is less complicated. 



2.08.15. On Aspen Mountain the ore bodies favor the contact 

 between the blue limestone and the brown dolomite. The former 

 is a very pure limestone, while the latter contains from 20 to 28$ 

 magnesium carbonate. The ore replaces and impregnates the blue 

 limestone, often with very little change in its appearance, but it 

 fills the numerous cracks in the more broken dolomite, coating 

 larger and smaller blocks. The ore occurs also in minor fissures. 

 On Smuggler Mountain the ore especially follows the fissure veins. 



