Tin ores and associated minerals-Continued.

Page.

Conditions and methods in the large tin mines of the world.

46

ILLUSTRATIONS.

Page.

PLATE I. Outline map of Seward Peninsula, showing position of York region,

Alaska.....

II. Topographic map of York region..
III. Valley of Lost River from the coast

IV. Cape Mountain

V. A and B, Thin sections of altered porphyritic dike near Tin Creek.. VI. A and B, Thin sections of porphyritic dike on Ear Mountain................ VII. A, Thin section of luxulianite from Ear Mountain; B, Polished surface of tin ore from Lost River

FIG. 1. Sketch of the coast from Cape York to Cape Prince of Wales.. 2. Geologic sketch map of York region.......

3. Sketch map of Lost River.....

4. Sluice boxes used in washing placer tin in York region

5. Box used in washing stream-tin concentrates.