REVIEWS 
Geology and Mineral Resources of Parts of the Alaska Peninsula. 
By WALLACE W. Atwoop. Bull. U.S. Geol. Surv. No. 467. 
All available material bearing upon the geology and mineral resources 
of the Alaska Peninsula have been compiled and presented in this bulle- 
tin, and a considerable body of new material secured during the season 
of 1908 by Wallace W. Atwood and H. M. Eakin while investigating the 
coal fields of the Alaska Peninsula is here presented for the first time. 
A large general map of the general geology of the peninsula and 
special detail maps of the Herendeen Bay and Unga Island region, and 
of the Chignik Bay region, are embodied in the report. 
The geologic formations exposed in the peninsula range in age from 
Upper Triassic to the present. The Herendeen section, which has been 
worked in detail, includes representatives of the Upper Jurassic, Lower 
and Upper Cretaceous, Eocene, Miocene, Pleistocene, and Recent. 
Associated with the clastic sediments of this region there are some lime- 
stones and vast quantities of volcanic material, some of which appear to 
be of late Eocene age and some post-Miocene. There are active vol- 
canoes in the region today adding to the pyroclastic rocks of the region. 
The available coal measures in the Herendeen Bay region are in the 
Upper Cretaceous formation. A poor grade of coal or lignite is also 
found in rocks of Eocene age. 
The Unga Island coal field located at Coal Harbor contains lignitic 
coal of Eocene age. 
The Chignik Bay section includes rocks of upper Jurassic age, Upper 
Cretaceous, Eocene, and later volcanic, glacial, and post-glacial forma- 
tions. The workable coal in the Chignik Bay field is also found in rocks of 
Cretaceous age. 
Mr. Atwood has included a description of the general geographic and 
climatic conditions in the Alaska Peninsula, the present status of gold, 
copper, and coal mining, and a series of suggestions to the prospector. 
The report is especially well illustrated with photographic views, 
numerous structure sections, and topographic sketches, and includes a 
somewhat full statement of the geomorphology of this portion of Alaska. 
The field work was carried on under difficult conditions and the report 
is a welcome addition to the available material on a little-known portion 
of the continent. 
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