ILLUSTRATIONS. 
Page. 
Plate I. Map of Alaska, showing mineral deposits so far as known 14 
II. Sketch map of southwestern Alaska 152 
III. Sketch map of Kachemak Bay, Cook Inlet 156 
Fig. 1. Sketch map showing geology near Tread well mines 71 
2. Cross section through Alaska-Treadwell mine and northern side of 
Douglas Island 74 
3. Ideal sketch showing manner in which faults of low dip may displace an 
inclined dike, giving appearance of alternate swelling and pinching. . 76 
4. Dike of albite-diorite in open cut of Ready Bullion mine SO 
5. Sketch map of the Turnagain Arm placer gold field 91 
6. Sketch map of the Rampart placer region 105 
7. Diagram showing field relations of the tin-bearing lodes on Cassiter- 
ite Creek 122 
8. Sketch map of Bering River coal field 141 
9. Sketch map of Bering River coal field, showing location of openings 
from which samples of coal analyzed were obtained 142 
10. Section of coal seams on Queen Creek 144 
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