4 CONTENTS. 
Analyses — Continued. Page- 
Igneous and crystalline rocks — Continued. 
Lake Superior region — Continued. 
3. Menominee River 82 
First. Sturgeon Falls gabbro 82 
Second. Lower Quinnesec Falls 83 
Third. Upper Quinnesec Falls 84 
Fourth. Schist from the Aragon iron mine 84 
4. Penokee-Gogebic region 85 
5. Rocks of Pigeon Point, Minnesota 88 
6. Mesabi district, Minnesota 93 
7. Miscellaneous rocks from Minnesota 95 
South Dakota 98 
Wyoming 99 
Yellowstone National Park and the Absaroka Range 103 
1. Electric Peak 103 
2. Sepulchre Mountain 1 06 
3. Absaroka Range 108 
First. Crandall Basin 108 
Second. Sunlight intrusives Ill 
Third. Ishawooa intrusives 112 
Fourth. Dikes in breccia 113 
4. Absarokite-shoshonite-banakite series 115 
5. Miscellaneous rocks 120 
Montana 127 
1. Madison and Gallatin valleys - 127 
2. Butte district 132 
3. Boulder batholith 135 
4. Crazy Mountains 137 
5. Little Belt Mountains 141 
6. Castle Mountain district 145 
7. ■ High wood Mountains 147 
8. Little Rock Mountains 151 
9. Bearpaw Mountains 152 
10. Elkhorn mining district 154 
1 1. Bitterroot Range 155 
12. Marysville district 155 
Idaho 156 
Colorado 159 
1. Denver Basin 159 
2. Pike's Peak district 160 
Granite 160 
Rocks of Cripple Creek district 162 
Miscellaneous rocks 164 
3. Silver Cliff and Rosita 166 
4. Buffalo Peaks 172 
5. Leadville region 173 
6. Tenmile district 176 
7. Elk Mountains 178 
8. West Elk Mountains 179 
9. San Juan region 180 
10. Miscellaneous rocks 1 85 
Utah 188 
1. Rocks from Tintic district 188 
