COAL. 107 



v 



KOTTTKUK REGION. 



Koyukuk River. — On Koyukuk River, in what was formerly supposed to be the 

 Kenai" series, lignite and coaly material in small amount is common in the sandstone, 

 grit, and especially in the conglomerate. The best occurrence is just above Tram- 

 way Bar, where there is a vein nearly 12 feet thick, of which the middle 9 or 10 feet 

 seems to be relatively pure fuel. Its analysis is given under No. 187 in the table on 

 page 111, which shows it to be a low grade of bituminous coal. There seems to be 

 no reason why with development this vein should not prove serviceable for local use. 



John Rimer. — Coal detritus in considerable quantity and of a character to suggest 

 the probable occurrence of coal of economic value somewhere in the region north of 

 this locality was seen in the John River gravels near the base of the Endicott Moun- 

 tains. This coal may apparent^ with safety be called a good grade of bituminous. 

 It breaks with a couchoidal fracture and has a bright shiny or glossy black surface. 



AECTIC SLOPE. 



Coal has been found also at several points on the Arctic slope, notably on 

 Anaktuvuk and Colville rivers. 



AnoMuvuk River. — Coal was first encountered by our party on the Anaktuvuk, 

 in the east bank, about 5 miles above the mouth of Tuluga River, about 130 miles 

 from the Arctic coast, in latitude 69° 11', longitude 151° 4'. This coal is of Upper 

 Cretaceous age, forming part of the Nanushuk series, from which the fossils at this 

 locality were collected. As shown in PI. XII, B, the rocks here dip steeply south, 

 at an angle varying from about 80° to nearly vertical, and rise to a height of 100 or 

 more feet above the river flats. The coal is conformable with the rocks of the series 

 of which it forms members and occurs in several beds, each a foot or more thick. It 

 is laminated parallel with the bedding, apparently denoting pressure. Though in 

 the weathered state it has the appearance of lignite, it is shown by No. 607 in the 

 table of analyses on page 114 to be a bituminous coal, having a fuel ratio of about 

 1.20. The quantity thus far observed, however, is hardly sufficient to lead to the 

 belief that the bed will prove of economic value in so remote a region. 



( ',,1 rill. R'n-er. — At about 30 miles north of the above locality and at a distance 

 of 100 miles from the coast, on the Colville, in the region of the mouth of the Anak- 

 tuvuk, in latitude approximately 69° 32', longitude 151° 30', lignitic coal appears in 

 considerable quantity. It is found in the Colville series, which underlies the Arctic 

 Coastal Plain in this region, and here rises 200 feet above the river nearly to the sur- 

 face of the plain, forming bluffs along the left or west side of the river for 10 miles 

 both above and below the mouth of the Anaktuvuk. (See PI. VIII.) 



a Sehrader, F. C, Reconnaissance along Chandlar and Koyukuk rivers, Alaska: Twenty-first Ann. Eept. U. S. Geol. 

 Survey, pt. 2, 1900, pp. 477 and 485. 



