670 
INDEX 
Irondequoit and Genesee, relative elevation of, 422. 
Ischua stone quarries, 492. 
Isotelus, 29. 
Ithaca group, 250. 
J. 
Jackson, Dr. C. T., surveys in Maine, Rhode-Island and 
New-Hampshire, 22. 
Java lake, 407. 
Joints, 163, 168, 192, 237, 239 ; their effect on vegetation, 
169 ; in the vicinity of uplifts, 300 ; cause of, 301; inter¬ 
rupted by interstratified sandstones, 304 ; dividing fossils, 
302; useful in quarrying, 302 ; vertical and striated, 331. 
Jointed structure of the rocks in the Fourth district, 299; 
of the limestones, 302; of the shales and sandstones, 303 ; 
of the conglomerate, 307. 
K. 
Knowledge of the rocks of New-York at the commencement 
of the survey, 7. 
17 . 
Lakes, 405 ; tables of elevation, length, breadth, etc. of, 411, 
412, 413 ; in Chautauque county, former elevation of, 496 ; 
elevation and depression of water in the Great lakes, 408; 
their relative elevation, 384; extent of the valley of St. 
Lawrence, 407. 
Lake, Bear, 407 ; Canadice, 407; Canandaigua, 121, 189, 
407; Cassadaga, 407; Cayuga, 121, 188, 212, 406; 
Chautauque, 407 ; Conesus, 405, 407 ; Crooked ( Keuka), 
188, 213, 220, 406 ; Hemlock, 407; Honeoye, 407 ; Java, 
407 ; Loon, 482; Seneca, 188, 212, 221, 227, 406 ; Silver, 
407. 
Lake Erie, future drainage of, 400. 
Lake levels, annual fluctuation of, 410 ; effect of winds on, 
410. 
Lake marl and tufa, 360. 
Lake ridges and beaches, 348 ; modern, 354 - 356. 
Lake shore in Monroe county, 423 ; in Niagara county, 442 ; 
and streams in Orleans county, 434; above Buffalo, 472. 
Lateral movements of strata, evidences of, 296. 
Lead, sulphuret, 86, 134, 194, 221. 
Lead ores of Wisconsin, Illinois and Iowa, 512. 
Lenticular clay iron ore, 60. 
Lewiston terrace, grooved rocks of, 329. 
Lighthouse at Portland harbor, 498. 
Lignilites, 95, 130; see Epsomites. 
Lima, 264. 
Lime, 466, 472, 484; sulphate (see Gypsum), 99,120-128, 
134, 311, 477 ; carbonate in crystals, 65, 67, 84, 96, 131, 
214, 239. 
Limestone, Birdseye, 28; Black-river, 28; Carboniferous, 
19, 179,411,508,511; Chazy,28; Corniferous, 161,450, 
508; Delthyris shaly, 144; Encrinal, 145; Niagara, 84; 
Onondaga, 151; Pentamerus, 144; Trenton, 29; Tully, 
212 ; Upper Pentamerus, 145. 
Limestone, of Clinton group, 62, 65; argillaceous and en- 
crinital, 481 ; concretionary, 480 ; oolitic, 508 ; vermicular 
or porous, 128; carboniferous, its absence in the Eastern 
States, 8 ; of Black-Rock and Niagara, considered as the 
same, 8 ; Blue of Ohio, its identity with the Hudson-river 
group, 503, 504; Cliff, 503, 506, 511 512. 
Lines of deposition, 230. 
Lingula, 28, 29, 48, 52, 76, 77, 108, 222; one of the earliest 
known fossils, and existing in our present seas, 10. 
Lithological changes accompanied by fossil changes, 33. 
Lithological characters of strata, value of, 501. 
Little ridge, 350. 
Littorina, 72, 142. 
Livingston county, rocks of, etc. 459. 
Llandeilo flags, equivalent to the Utica slate, 29. 
Local geology, 414, 422, 433, 440, 449, 453, 458, 459, 464, 
469, 475, 477, 480, 484, 488, 493. 
Localities of the Chemung group, 258, 276 ; of the Clinton 
group, 66 ; Genesee slate, 220; Hamilton group, 193,211; 
Marcellus shale, 179, 183; Medina sandstone, 42; Nia¬ 
gara group, 96; Old Red sandstone, 280; Onondaga 
limestone, 156 ; Onondaga-salt group, 118 ; Portage group, 
237, 248 ; Tully limestone, 214. 
Locke, Dr., report on the geology of Ohio, 23. 
Lockport, 83, 88, 99, 100. 
Lockport limestone, 80. 
Long pond, 356. 
Lower falls of the Genesee, 382. 
Lower green shale, 59, 60. 
Lowest position of remains of fishes, 145. 
Loxonema, 137, 200, 256. 
Lucina, 245. 
Ludlow formation, equivalent to the Chemung group, 278. 
Ludlowville shales of Hamilton group, 187. 
Lymnea, 361, 396, 479. 
M. 
Mackinaw, 118 ; rocks at, 512. 
Maclure, Mr., his labors on the geology of the U. States, 4. 
Maclurea, 28. 
Madison, Indiana, rocks at, 506. 
Magnesia, 63, 96, 98, 130. 
Magnesian deposit, 117, 128, 141. 
Magnesian character of the Niagara limestone, 84, 85. 
Magnetic iron sand, 426. 
Manchester sulphur springs, 313. 
Manganese, oxide, 44, 260, 490. 
Manures, their application, 240. 
Maple ridge, 434. 
Marble’s quarry, waterworn rock at, 415. 
Marble, variegated of Lockport, 448. 
Marcellus shale, general characters and subdivisions, 177; 
localities and thickness of, 179; minerals and springs, 
179; agricultural characters, 179; organic remains, 180 ; 
localities of superposition, 183 ; local details of, 451, 457, 
461, 466, 472, 503, 508. 
Marl, .. 360, 487, 446, 453, 457, 464, 468, 477, 479, 484, 
490, 496; gypseous, 418 ; its origin, 360; great deposit in 
Livingston county, 463 ; and tufa, 360, 428, 491. 
Marshes, elevation of, 357 ; and swamps, 416; Cayuga, 359, 
416. 
