CONTENTS. 
J*age. 
introduction 11 
Lnalyses — 19 
Igneous and crystalline rocks 19 
Maine 19 
1 . Rocks from Aroostook County 19 
2. Litchfieldite and associated minerals 21 
New Hampshire 23 
Vermont 24 
1 . Rocks of Mount Ascutney 24 
2. Miscellaneous rocks 27 
Massachusetts 28 
1. Rocks of the Connecticut Valley 28 
2. Miscellaneous rocks 33 
Connecticut : 35 
New York 36 
1. Rocks of the Adirondack region 36 
2. Peridotite from near Syracuse 38 
New Jersey 39 
Pennsylvania 40 
Delaware 41 
Maryland, District of Columbia 42 
1. Peridotite and pyroxenite 42 
2. Gabbro and diorite 44 
3. Granite and gneiss 46 
4. Miscellaneous rocks 50 
Virginia 51 
North Carolina 52 
Georgia 55 
Kentucky 56 
1. Elliott County dike 56 
2. Crittenden County dike 58 
Tennessee 59 
Missouri 59 
Arkansas 60 
Texas 60 
Lake Superior region 64 
1. Marquette region, Michigan 64 
2. Crystal Falls district, Michigan 66 
3. Menominee River 70 
First. Sturgeon Falls gabbro 70 
Second. Lower Quinnesec Falls 71 
Third. Upper Quinnesec Falls 72 
Fourth. Schist from the Aragon iron mine 72 
5 
