INDEX 
A. 
Acabonnick marshes, page 18. 
Acantholoma, 345. 
Achnanthes, 50, 52, 241. 
Acid carbonic, 241. 
Actinocyclus, 50, 52, 69. 
Actynolite, 562. 
Adit level, 358, 359, 360. 
Adsett, Mr. 393. 
Adularia, 539. 
Advantages of the lead mines of the 
Shavpangunk, 361. 
Agaric mineral, 236. 
Agate, 282, 412. 
Age of limestone of Westchester co. 
627. 
— quartz rock, 627. 
Age of rocks of Bellevale mountain, 
Skunnemunk mountain & Pine 
hill, 362, 365, 626. 
— drift, 627. 
— Hudson river rocks, 377,405, 626. 
— Long-island division, 627. 
— limonite, 495. 
— metamorphic limestones, 627. 
— quaternary, 468, 476, 486, 627. 
— red sandstone, 627. 
— laconic rocks, 438, 626. 
— trap, 627. 
— upper drift, 627. 
Ages of various rocks, 626-628. 
Alabama, 2. 
Alabaster, 483. 
Albany land-slips, 33. 
— mineral springs, 101. 
Alluvial depositions, 5. 
— more abundant now than formerly, 
5, 9, 10. 
— consequent obstructions at the 
Overslaugh, 5. 
— dredging or elongation of dykes 
only means of obviating, 5. 
Alluvial division as part of the quater¬ 
nary system, 2. 
Geol. 1st Dist. 
Alluvial division as part of the quater¬ 
nary system, definition of, 4. 
— sandstones and conglomerates, 
122, 236. 
— causes of, 122, 236. 
— supplement to, 229. 
— chemical agencies, 37. 
— disintegration, 37. 
— causes of, 39. 
Alluvial changes ; encroachments of 
the sea, 19 to 23. 
— connection of islands with each 
other, 19-23. 
— effects of streams damming up 
larger ones, 90. 
— effects of frost, 36, 
— effects of lightning, 38. 
— excavating action of water, 42. 
— formation of beaches, spits, bars, 
etc. 24 - 30. 
— islands along south coast of Long 
island, 20. 
— sandunes, 30. 
— sinks, 36. 
— slides, 32. 
— transport by ice, 39. 
— transport by ground ice, 41. 
Alluvial deltas, 5, 9. 
Alluvial marsh, 12. 
Alluvions, fluviatile, 4. 
— of the Battenkill, Catskill, Hoo- 
sick, Hudson, Mohawk, 4, 5. 
— Lake Champlain, 6. 
Alluvions, lacustrine, 10. 
— infusorial, 48-77. 
— marine, 17. 
— of Long island, 25. 
Alluvions from solution, 79. 
Allanite,478,484. (VideHighlandite.) 
Alum, 84, 85. 
Alum slate, 84, 85, 429. 
Amianthus, 284, 481, 483, 577. 
Amenia gas spring, 106. 
Amphiphora, 49. 
84 
Amphibole, 465. 
Amygdaloid, 279, 281, 282. 
Anatomy (comparative), its use in geo¬ 
logy, 45. 
Ancram creek delta, 8. 
Anhydrous sulphate of lime, 84, 
Animal secretion of lime, silex, etc. 78. 
Anthony’s Nose flats (alluvial), 9. 
Anticlinal axis, etc. 331 - 336, 356 - 
357, 367, 373, 374, 375, 377, 381, 
382, 390, 405, 424. 
Anthophyllite, 461, 518, 521, 582, 592, 
596. 
Anthracite used in making bricks, 144. 
— lime, 319, 411, 453, 455. 
Anthracite, 372,373, 390,392,415, 421, 
448, 449. 
Apatite, 467. 
Aqueduct, Croton, 147. 
Arctic character of quaternary shells, 
277 - 278. 
Argillaceous iron ore (columnar), 261. 
Argillite (transition), 367, 370, 377. 
Arkansas river, coal of, 3. 
— cretaceous formations, 3. 
Arragonite, 577. 
Arched strata (inverted), 352, 367, 
380, 388. 
Argentiferous galena, 498 - 500. 
Arseniate of iron, 115, 119, 468. 
Arsenical iron, 577. 
Arsenic, compounds of, 115, 119. 
Arthrodesmus, 52, 56, 60. 
Asaphus, 338, 339, 345, 350. 
Asbestus, 456, 480, 481, 577. 
Ascidopsis, 345. 
Astrocrinites, 346, 347, 349. 
Athens tufa, 81. 
Atrypa, 337, 339, 341, 343, 345, 346, 
349. 
Augite, 456, 459, 465, 466, 487, 531, 
538 - 539, 577. 
Augite rocks east of the Hudson, 441, 
466, 531 - 532. 
