112 RECONNAISSANCE IN NORTHERN ALASKA IN 1901. 



The Corwin mines, which at present seem to be by far the most important, 

 accessible, and productive, are situated farther to the southwest, near the south- 

 western limit of the coal measures referred to by Dall, and about 30 miles east 

 of Cape Lisburne (see PI. V). Coal is reported to have been obtained here by the 

 whaling vessels as early as 1879. Its occurrence, so far as observed, is in 10 or 12 

 lulls, varying from 1 to 16 feet in thickness, all being apparently quite persistent. 

 The edges of these beds are exposed for a distance of about three-eighths of a mile 

 along the coast, -which cuts them diagonally, forming a steep cliff that rises from 

 30 feet on the west to more than 100 feet above tide on the east, where it attains its 

 maximum in a low prominence known as Corwin Bluff. The coal beds, conformable 

 with the country rock in which they occur, strike N. 45° W. and dip southwestward 

 at an angle of 36°, as shown in PI. XIII, B; but eastward, in Corwin Bluff, where 

 the rocks are more disturbed, the dip steepens. 



The country rock in which the coal occurs, as shown in the above view, is 

 sandstone, shale, and slate, and is probably Jura-Cretaceous. It is more fully 

 described under the head of geology, page 72. As noted, it very much resembles 

 the rocks of the Anaktuvuk series, but is supposed to be older. 



Some of the coal in the Corwin mines has been partially crushed, but not greatly 

 damaged, by rock movement. In mining much of it is taken out in large blocks, 

 1 to 2 or more feet in diameter, and nearly all of the beds are comparatively pure. 

 Average samples collected by the writer gave the analyses under numbers 669 and 

 671 in the accompanying table, page 114, showing the product to be a bituminous 

 coal of fair grade, with a fuel ratio of 1.10 and 1.30. It Is, however, hardly satis- 

 factory for blacksmithing or steaming purposes. It was used on the steamship 

 Arctic, on which the party took passage for Nome, but with much the same results 

 as indicated by Mr. Woolfe. Though it burns readily and produces steam quickly, 

 it is of low specific gravity and not lasting. It takes about double the amount of this 

 coal as compared with Cpmax coal to maintain a given steam pressure. It burns 

 with little smoke, but produces a large amount of ash and clinker. This instance, 

 however, can hardly be considered a fair trial, as, owing to the want of timber, the 

 facilities for mining were so poor that much "bone," rock, and dirt, or foreign 

 debris found its way into the coal and thence into the furnace. The coal is reported 

 to be good for cooking and household purposes. 



Mr. Charles L. Norton," of the Massachusetts Institute of Technology, is said to 

 have made the following report to the Corwin Trading Company on "Cape Lisburne 

 coal," which was probably collected at or in the region of the Corwin mines: 



"I rind that the specimens of Alaska coal which you recently sent me have a 

 calorific power of 7,560 calories per gram. This is quite as good as the average 

 western coal, and is not more than 10 per cent inferior to the best eastern coals." 



a Brooks, A. H., The coal resources of Alaska: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 1902, p. 566. 



