INDEX 



167 



Marcellus shale, exposures, 56 a , 72\ 



Medina sandstone, outcrops and 

 contacts, 6 6 . 



Merrill, F. J. H., cited, 100 2 . 



Merrill, G. P., cited, 93 1 . 



Microcline, 115 5 . 



Microperthite, 107 T , 115 5 , 142 s , 142 a , 

 144 5 , 150 6 , 154 8 , 159 5 . 



Minerals, in anorthosite, 99 9 -105 2 ; in 

 diabase, 117 4 -22 3 ; of economic val- 

 ue, in Franklin county, 125 2 -26 4 ; 

 in gabbros, 109 5 -14 9 ; in gneiss, 96 7 - 

 99 4 ; in granite, 114 9 -17 4 ; of Gren- 

 ville series, 92 s -95 4 ; in syenitic 

 rocks, 105 3 -9 5 ; table, 120-22. 



Muscovite, 154 7 . 



Newark rocks of Rockland county, 

 5 7 , 9-50; reptile and other verte- 

 brate tracks, 14 2 ; thickness, 21 u ; 

 conditions of formation, 49 3 -50 9 . 



Newland, D. H., Report on progress 

 made, during 1898, in mapping 

 the crystalline rocks of the west- 

 ern Adirondack region, 129-35; 

 Preliminary report on the geolo- 

 gy of Hamilton, Warren and 

 Washington counties, 137-62; 

 cited, 141 4 . 



Niagara limestone, exposures, 66*, 

 68 2 ; illus. facing p. 70. 



Norites, 101 8 , 102 2 , 111 2 . 



Nyack, sandstone exposures, 17 2 ; 

 trap rock exposures, 26 5 , 33 s . 



Oligoclase, 98 5 , 107 1 , 107 3 , 107 T , 115\ 



Olivine, 119 3 . 



Onondaga limestone, exposures, 56 1 , 

 61 9 , 63 2 , 65 7 , 72 4 . 



Ontario county, revised geologic 

 map, 6 5 . 



Ophicalcites, 93 1 . 



Oriskany fauna of Becraft moun- 

 tain, 6 9 . 



Oriskany sandstone, exposures, 55", 

 59 s , 60 6 , 61 7 , 63 1 , 65 3 , 72 2 . 



Orthoclase feldspars, 93 6 , 96 9 , 98 2 , 

 98 5 , 99 4 , 100 5 , 107 1 , 107 6 , 114 3 , 142 9 , 

 142 9 , 144 3 , 144 5 , 154 6 , 154 8 , 159"'. 



Orthoclase gneisses, 78 6 , 90 2 , 96 7 -97 9 , 

 99 4 , 116 1 , 116 s , 125 7 . 



Oswego sandstone, outcrops and 

 contacts, 6 6 . 



Paleontologic investigations, 6 2 , 6 7 . 



Paleozoic rocks of Adirondacks, 

 thickness, 76 9 ; of Franklin coun- 

 ty, 123 4 -25 1 ; of Warren county, 

 161 5 ; near Wells, 145 5 -52 8 . 



Palisades, 22 6 -39 3 ; causes of eleva- 

 tion, 38 4 ; illus. facing p. 10, 22, 

 26. 



Pegmatite, 97\ 144 3 , 145 3 , 154 7 , 155 8 . 



Pentamerus limestone, exposures, 

 53 4 , 54 2 , 57 7 , 58 2 , 59 3 , 60 8 , 62 3 , 63 4 , 

 64 5 , 66 5 , 70 6 , 71 s ; illus. facing p. 54, 

 60, 68; quarries, 67 3 , 71 2 ; analysis, 

 71 4 . 



Phlogopite, 92 9 , 155 9 . 



Piermont, sandstone exposures, 16°; 

 trap rock exposures, 25 9 -26 3 , 36\ 



Plagioclase feldspars, 96 9 , 98 2 , 98% 

 107 c , 111 2 , 115 5 , 144 3 , 144 5 , 150 5 , 

 154°, 154 s , 159 5 . 



Porphyrites, diabase, 119 1 . 



Porphyritic gneisses, 103 1 , 143 2 . 



Porphyry, syenite, 117 3 , 118 6 , 118 8 . 



Portage fauna, investigations, 6 3 , 6 9 . 



Portage formations, report on strat- 

 igraphy and paleontology, T. 



Portland cement, manufacture, 71 s . 



Potsdam sandstone, exposures, 75°- 

 76 2 , 145 7 , 147 3 -48 1 ; building stone, 

 126 5 ; road material, 127 s ; boul- 

 ders, 161°. 



Precambrian rocks of Franklin 

 county, 89 5 -123 4 . 



Prosser, C. S., Sections of the for- 

 mations along the northern end 

 of the Helderberg plateau, 7 2 , 51- 

 72. 



Pyrite, 93 7 , 100 5 , 107 3 , 114 2 , 144°, 150 6 . 



