INDEX 



The superior figure shows the exact place on the page in ninths; e. g. 1217 

 means seven-nintbs of the way down page 121. 



Acadian group, 143 1 , 144 2 . 



Actinolite, 1215. 



Adirondack^, Plutouic rocks, 124 5 , 139 2 ; 

 Archaean rocks, 140 9 -41 3 ; limestone, 

 1428; sandstone, 1428, 1447; j r0Il 

 ores, 218 6 . 



Aeous, see Geologic time. 



Aguotozoic series, 135 9 , 141*. 



Air, 119 s ; geologic changes produced 

 by, 128*, 1792, 2395. 



Albany county, Hudson river group, 

 149 6 ; lower Helderberg group, 157 8 . 



Albite, 1212. 



Amphiboles, 121 5 . 



Andesite, 1212, 1252. 



Animals, classification, 130-31. 



Auorthite, 1212. 



Auorthosite, 141 1 . 



Authony's Nose, 124 5 . 



Antwerp red hematites, 219 6 . 



Apatite, localities producing, 233 8 . 



Aragonite, 120 6 . 



Archaean series, 138 5 -40 6 ; term defined, 

 138 5 ; exposures, 138 8 -41* ; typical 

 localities, 1406-41*. 



Archaean time, 135 9 . 



Archaeopteryx, 172 7 . 



Argillite, 196*. 



Aristotle, geologic observations of, 

 1137. 



Arrow-heads, material, 173 7 . 



Arsenic, localities producing, 231 8 . 



Asbestus, 121 7 . 



Ashburner, C : A., articles on produc- 

 tion of oil, 228 2 . 



Asphalt, 122 7 . 



Atmosphere, see Air. 



Augite, 1218, 1252. 



Barite, localities producing, 233 9 . 



Basalt, 1252 ; constituents, 121 8 . 



Beaver, fossil, 178 9 . 



Beck, L. C, mineralogist, 241 s . 



Biotite, 1222. 



Birds, of Jurassic period, 172 7 ; of 



Tertiary period, 175 6 . 

 Birdseye limestone, 147 5 , 147M8*, 200 5 . 

 Bishop, I. P., photographs by, 110 9 . 

 Black lead, 122 7 . 

 Black marble, 148 5 . 

 Black river limestone, 147 5 , 148 4 . 

 Blue Kidge, formation, 151 6 . 

 Bluestone, 192*-933. 

 Boundary line, resurvey, 245 s . 

 Breakneck mountain, 124 5 . 

 Brouze age, 179 7 . 

 Bronzite, 1222. 



Brown hematite ore, see Limonite. 

 Brownstone, 195*. 

 Building stones, 148 s , 149 s , 152 7 , 160«, 



181-204. 

 Burden iron mines, 222 1 . 



Calcareous tufa, 120 7 , 203 2 ; localities 

 producing, 234 2 . 



Calciferous group, 146 8 -47*. 



Calciferons saudrock, 199 6 . 



Calcite, 120 6 ; localities producing, 

 2342. 



Cambrian system, 138*, 142 2 -46 3 ; origin 

 of name, 142*; depth in Washington 

 county, 145 9 ; life of, 146 1 . 



Cannon's Point, 124 6 . 



Carbonate of lime, localities produc- 

 ing, 2342. 



Carbonate ores, 221 9 -22*. 



Carbonic acid gas, 228 8 . 



