ILLUSTRATIONS. 
Page. 
Plate I. Topographic map of the Iron Springs quadrangle . In pocket. 
II. Geological map and sections of the Iron Springs quadrangle In pocket. 
III. Detail maps of the iron-ore deposits on (1) Great Western claim, (2) 
McGarry claim. (3) War Eagle and Marshall claims, and (4) Granite 
Mountains In pocket. 
IV. Detail map of the iron-ore deposits on east slope of Iron Moun- 
tain In pocket. 
V. Detail maps of the iron-ore deposits at Desert Mound and between 
Crystal Springs and Oak Springs, Iron Mountain In pocket. 
VI. Detail maps of the iron-ore deposits on the Duluth group, Chesapeake 
and Excelsior claims, the summit and south and west slopes of 
Iron Mountain In pocket. 
VII. A, Iron Springs Valley and The Three Peaks; B, Cretaceous sedi- 
ments near The Three Peaks 16 
VIII. A, Erosion forms of the latest trachyte, Swett Hills; B, Erosion 
forms of the laccolithic andesite, Three Peaks; C, Concretionary 
erosion of the laccolithic andesite, Three Peaks 22 
IX. A, Graphic representation of composition of fresh limestone; B, 
Graphic comparison of composition of altered limestone "H" with 
fresh limestone 26 
X. A, Graphic comparison of composition of altered limestone "I" with 
fresh limestone; B, Graphic comparison of composition of altered 
limestone "J" with fresh limestone 26 
XI. A, Graphic comparison of composition of altered limestone " K " with 
fresh limestone; B, Graphic comparison of composition of altered 
limestone " L " with fresh limestone 30 
XII. A, Graphic comparison of composition of altered limestone "N " with 
fresh limestone; B, Graphic comparison of weathered andesite 
"B." with fresh andesite 30 
XIII. A, Graphic comparison of altered andesite "C" with fresh andesite; 
B, Graphic comparison of altered andesite "D" with fresh ande- 
site 48 
XIV. A, Graphic comparison of altered andesite "E" with fresh andesite; 
B, Graphic comparison of altered andesite "D" with altered 
andesite " C " 50 
XV. Map of mining claims in the Desert Mound and Iron Springs areas, 
Iron Springs district 66 
XVI. Map of mining claims of the Iron Mountain area, Iron Springs dis- 
trict 66 
XVII. A, Southern Cross iron-ore deposit, east of Granite Mountains; B, 
Chesapeake iron-ore fissure vein, Iron Mountain 68 
XVIII. A, Great Western iron-ore fissure vein in southern part of Three Peaks 
laccolith; B Iron-ore blowout south of Iron Mountain laccolith. . . 68 
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