16 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



New Zealand. — According to Hutton,-* conditions favoring ac- 

 cumulation of coal existed in New Zealand at several horizons, but 

 only during brief periods. The seams are nowhere thick enough to 

 repay mining. One, 6 feet, is merely carbonaceous shale with 

 numerous streaks of coal. 



Alaska. — The Jurassic area of northeastern Alaska was ex- 

 amined by Collier,-^ who made a reconnaissance survey of the Cor- 

 win formation, probably Upper Jurassic, between meridians 163 and 

 165, beyond the 69th parallel. The formation is present at 100 

 miles farther east and notes by other explorers lead to the belief 

 that it extends far inland ; Collier's studies were confined to the 

 Arctic coast line. Lithologically, the formation consists of thinly 

 bedded shales, conglomerates, sandstones and coal seams. Shales 

 predominate, more or less calcareous, gray brown to black and vary 

 from mere mudstone to sandy shale. The sandstones and con- 

 glomerates are few and seldom exceed 10 or 12 feet. The pebbles 

 are of quartz and chert, the largest being about 4 inches in diameter. 

 The thickness is at least 15,000 feet and the coal area within the 

 district covers not less than 300 square miles. Mining operations 

 were insignificant and the studies were made almost wholly upon 

 outcrops. 



The coal seams appear to be in two groups, Corwin, above, and 

 Thetis, below, separated by a great thickness of barren measures. 



The highest seam in the Corwin, 4 feet, 6 inches and without 

 parting, is enclosed in black shale or shaly sandstone. Some thin 

 beds and impure coals were seen in the interval, 1,000 feet, to the 

 next workable seam, which is 5 feet thick and divided by two thin 

 partings of clay. Its roof is shaly sandstone and the floor is hard 

 clay. The next seam, 500 feet lower, is the Corwin, which was 

 opened many years ago, but the opening was inaccessible at the 

 time of Collier's visit, being covered by a great snowdrift. This 

 seam, about 1,000 feet above the bold conglomerate of Corwin Bluff, 

 is said to be 16 feet thick, of which 7 feet are practically clean coal, 



2*F. W. Hutton, "Geology of Otago," Dunedin, 1875, PP- 99. 100; Geol. 

 Survey of New Zealand, Reps, for 1873-74, P- 36. 



25 A. J. Collier, " Geology and Resources of the Cape Lisburne Region, 

 Alaska," U. S. Geol. Survey, Bull. 278, 1906, pp. 27, 28, 37-40. 



