ALASKA COAT, FIELDS. 43 
rather indefinite, the evidence being incomplete and conflicting. The 
Tertiary coal-bearing recks on the Yukon rest upon the Cretaceous 
with an apparent conformity, thus suggesting that the lower beds 
are basal Eocene or even transitional from the Mesozoic t > the Ceno- 
zoic. Other evidence, including the relation of the floras of the 
Kenai formation to those of other regions and the relation of these 
beds to the overlying Miocene, indicates that the Kenai coal is upper 
Eocene or Oligocene. The coal floras on Bering River include forms 
suggesting those of the Kenai and other forms which are strangers 
to those beds and which Knowlton considers possibly Miocene. Still 
younger coal occurs at Yakutat Bay, where there are no rocks of 
Kenai age and where the floras belong very high in the Tertiary. 
The total evidence thus suggests that the Tertiary coal of Alaska 
occurs at several distinct horizons. 
OCCURRENCE OF COAL.« 
PACIFIC COAST REGION. 
The Pacific coast coal fields are of moderate area but of wide dis- 
tribution. They include both Mesozoic anil Tertiary coals, with the 
complete range in ^composition from a good quality of anthracite, 
through high-grade semibituminous steam and coking coals and ordi- 
a The following references include the latest and most complete reports on each region. Earlier 
reports of importance, when referred to in later ones, are not mentioned here. 
PACIFIC COAST REGION. 
Martin, G. C, The distribution and character of Bering River coal: Bull. r. s. Geol. Survey No. 284, 
1906, np. 65-77. 
A reconnaissance of the Matanu ska coal f> eld, Alaska, in 1905: Bull. U. S. Geol. Survey No. 289, 
1906, 36 pp. 
Geology and mineral resources of the Controller Bay region. (In preparation.) 
Paige, Sidney, The Ilerendeen Bay coal Held: Bull. U. S. Geol. Survey No. 284, 1906, pp. 101-106. 
Paige, Sidney, and Knopf, Adolpji, A reconnaissance in the Matanuska and Talkeetna basins. (In 
this volume, pp. 104-115.) 
Stone, R. W., Coal resources of southwestern Alaska: Bull. V. S. Ceo!. Survey No. 259, 100."., pp. 
151-171. 
— Coal fields of the Kachemak Bay region: Bull. U. S. Geol. Survey No. 2."7, 1906, pp. 53-73. 
Wright, C. W., A reconnaissance of Admiralty Island, Alaska: Bull. U. S. Geol. Survey No. 287. 1907, 
pp. 151-154. 
INTERIOR REGION. 
Collier, A. J., Coal resources of the Yukon basin, Alaska: Bull. t'. s. Geol. Survey No. 218, ion:;, 
71 pp. 
Mendeniiall, YV. C, Geology of the central Copper -River region, Alaska: Prof. Paper U. s. Geol. Sur- 
vey No. 41, 1905, pp. 123-125. 
PRINDLE, L. M., The Bonnifield and Kantishna regions. ( in I his volume, pp. 221-220. i 
BERING SEA AND ARCTIC SLOPE. 
BROOKS, A. II., Coal resources of Alaska: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 1902, 
pp. 515-57L 
Collier, A. .1., Geology and coal resources of the Cape Lisburne region: Bull. U. S. Geol. Survey No. 
278, 1906, 51 pp. 
Moffit, F. II., The Fairhaven gold placers, Seward Peninsula, Alaska: Bull. U. s. Geol. Survey v 
247, 1905, p. 67. 
Schrader, F. c, Reconnaissance in northern Alaska, across the Rocky Mountains, along Koyukuk, 
John, Anaktuvuk, and Col ville rivers and the Arctic coasl to Cape Lisburne, in 1901: Prof. Paper 
U. S. Geol. Survey No. 20, 1904, pp. 106-114. 
