124 ' GEOLOGICAL SURVEY OF THE TERRITORIES. ' 



12. Sandstone. 

 11. Drab clay. 

 10. Coal, (No. 3.) 



9. Drab clay. 



8. Sandstone, 25 feet. 



7. Drab clay. 



6. Coal, (No. 2,) 8 feet. 



5. Drab clay. 



4. Sandstone, about 25 feet. 



8. Drab, fire-clay, 4 feet. 



2. Coal, (No. 1,) 11 to 14 feet. 

 1. Sandstone. 



" In bed No. 22 there are three layers of sandstone, which contain a 

 great variety of impressions of leaves. Below coal-bed No. 6 there is a 

 bed of drab clay, 7 feet thick, with a coal-seam at the outcrop, 3 feet 

 thick ; but the coal appears to give out or pass into clay as the bank is 

 entered, so that there are 10 feet of clay above coal-bed No. 6. Much of 

 the iron-ore is full of the impressions of leaves in fragments, stems, grass, 

 &c. The ore is mostly concretionary, but sometimes it is so continuous 

 as to give the idea of a permanent bed. Above coal-bed 5 there is a 

 seam of iron, with oyster- shells, apparently Ostrea suMrigonalis.''^ 



Professor Lesquereux estimates, allowing for wastage, &c., that 

 90,000,000 tons of lignitic coal are probably obtainable from beneath 

 twenty-five square miles of the Bowlder Valley region. In arriving at 

 this amount, he considers the total thickness of coal obtained over this 

 area as being only 9 feet. For analysis see Table A, Nos. 16, 17. 



Fullerton bank ; range 70 west, township 1 south, section 21. 



Coal Creek openings : range 70 west, township 1 south, section 33. 

 These are about three miles south of the Marshall and Fullerton mines, 

 and are separated from them by a plateau twelve to fi.fteen hundred feet 

 high. They were first opened in 1860, when a drift of 150 feet was driven. 

 The bed opened probably corresponds with the sixth coal-bed, or bed No. 

 23, of the Marshall-mine section, and was here 7 feet thick. Six other 

 beds have also been found, all dipping eastward at an angle of about 43°, 

 but steepening in dips to 68° north of the stream. Underneath the 

 third bed is a layer of excellent fireclay, 6 or 7 feet thick, having in it 

 nodules of iron-ore containing impressions of leaves of deciduous trees. 

 The bed that was opened had but little clay on either side between it 

 and the usually inclosing sandstones, while above the upper sandstone 

 is another bed of coal and more fire-clay. "Above the coal the clay is 

 very irregular, sometimes thinning out entirely, so that the sandstone 

 comes directly upon it." All the beds of coal are so badly crushed to- 

 gether that they are rendered somewhat obscure. 



From Coal Creek the sandstone ledge above the coal can be easily 

 traced south about four and one-half miles over a broad and highly ele- 

 vated plateau to the Leiden mine, range 70 west, township 2 south, 

 section 28. 



The bed here appears on the western side of a sandstone ridge, and is 

 bent over slightly beyond the vertical, and appears dipping at a high 

 angle toward the mountains. The owner in September, 1870, lost his 

 life by entering the mine when the air was foul in consequence of its 

 having been left unworked for some time. 



Following on still south about a mile, we come to the Murphy 

 mine: range 70 west, township 2 south, section 33, on Kalston Creekj 

 about five miles north of Golden City, and but twelve or thirteen 

 miles from Denver, with which it will shortly be directly connected by 



