indp:x. 
151 
i. 
Page. 
Igneous slates, analyses of 18 
origin of 5 
Ijamsville, Md., slate deposits at 33,69 
Imports of slate, table of 132-133 
Iron, color of slates due to 7 
J. 
Jackson (Stephen) &, Co., slate quarry of... 79 
Jamesville, N. Y., slate quarries at 32-33 
Janiesville-Hampton, Vt., section through. 95 
Jannetaz, E., experiments by 8,27 
Joints, description of 27-29 
occurrence of 27-29 
relations of dikes, shear zones, and 28,44 
Joints, curved, occurrence of 28 
Joints, plicated, occurrer.ee of 28 
Jones (Foulk) & Sons, quarry of, structure 
in 86 
slate deposits of 28 
K. 
Kansas City Slate Quarrying Co., slate quar- 
ry of 52 
Kaolin in slates, occurrence of 12 
Keith, Arthur, on Tennessee slates 88 
Keyes, C. R., section by 67-68 
King, Moses, orbicular granite in quarry of . 90 
Knots in slate, occurrence of 11-12, 14 
L. 
Lake Bomoseen, Vt., section at 97 
Lake Bomoseen Slate Co., slate of 15-16, 97 
Lebanon Springs, N. Y., slate quarry near.. 74 
Lehigh Gap, Pa., slates of 10 
Leith, C. K., on cleavage 9-10 
Lenses in slate, occurrence of 11-12, 14 
Lime in slate, occurrence of 46 
Limonite in slates, occurrence of 11, 12 
Lindgren and Turner, on California slates. . 56 
Little Missouri Creek, slate deposits of 52 
Lloyd, E. E., slate quarry of, shear zone in, 
plate showing 30 
Lobb, Wm., & Sons, slate quarry of 79 
Loretz, on slip cleavage 24 
Lost Hannah bed, Arkansas, slate from... 54,124 
Lowell Slate Co., slate quarries of 65 
M. 
McCulloch, Gilbert, analyses by 88 
Magnesia, color of slate due to 67 
Magnetite in slate, occurrence of 14, 27, 11, 46 
Maine, slate deposits of, description of 61-67 
slate deposits of, location of 60 
location of, map showing 61 
slate of, characteristics of 123-125 
grain in 34 
luster of 10 
prices of 125 
production of . . 126-131 
structure of 27 
Mammoth Red Beds, Arkansas, slate from. 51, 124 
Map of Arkansas slate localities 52, 54 
of Maine slate region 61 
of Maryland slate region 68 
of Maninsburg, W. Va., slate region ... 120 
Page. 
Map of New York and Vermont slate belt. . 88 
of Slatington, Pa., quarries 80 
of United States, showing location of 
slate deposits 5 
of Virginia slate region 112 
Map, geologic. See Geologic map. 
Marcasite, occurrence of 46 
Martinsburg, W. Va., clay-slate deposits 
near t;, 111, 1 L9, 124 
clay-slate deposits of, location of. map 
showing 120 
Martinsburg shale, slates of 119 
Maryland, slate deposits of, description 
of r,7-7n 
slate deposits of, location of 67-69 
location of, map showing 63 
slate of, characteristics of 6, 124 
geology of 6, 34 
production of 126-131 
veins in 33 
weathering of 34 
See also Peach Bottom region. 
Massachusetts, slate deposits of, production 
of 126-131 
Mathews, E. B., on talc in Maryland 
slate 69 
Mathews Consolidated Slate Co., slate 
quarry of 74, 95, 1 23 
Maw, George, on ribbons in Welsh slate 17 
Meadow Slate Co., slate quarry of 101 
Mena, Ark., slate deposits at 53-54, 124 
Merrill. G. P., on slate weathering 37 
on waste in slate manufacture 42 
Merrill-Brownville Slate Co., quarry of, 
view of 66 
slate quarries of 65-67, 1 2:; 
Mernman Mansfield, on slate characteris- 
tics 47-49, 73-74, 77, 79, 88 
recent tests of slates by 122-124 
Metamorphism, effects of 7 
Mica, formation of 8 
Mica slates, classification of 6 
origin of 5, 7-8 
See also Slates. 
Michigan, slate production of 126-131 
Middle Granville, Vt., section at 95-97 
Millstock slate, description of 108-109 
Minerals in slate, character and occurrence 
of 5-6,11-15 
classification of 14 
Mineralsingreen and purpleVermontslate, 
occurrence of 109-110 
Mineral analyses. See Analyses. 
Minnesota, slate deposits of, bibliography 
of 70 
slate deposits of, location of 70 
slate of, production of 126-131 
Monson, Me., slate deposits at 10,61-64,125 
Monson Consolidated Slate Co., slatequarry 
of 61,64,123 
Monson Maine Sla'e Co., slate quarry of . . . 61-63 
Monson Pond, Me., quarry at, section of . . . 62 
quarry at, slates of 61-63, 124 
Montpelier, Vt.. slate quarry at 90,93 
Mount Ephraim, Md., slate prospect near. . 70 
Moyer (J. S.) & Co., quarry of, machinery 
of, view of 78 
