131 



from the sea, a succession of falls must first have been established 

 near Queenstown. The first or uppermost fall, he argues, must 

 have been of moderate height, when the land was sufficiently raised 

 to wear away the Niagara shale, and undermine the incumbent lime- 

 stone, which is of slight thickness at its termination near Queens- 

 town. This upper fall having thus cut its way backwards, while 

 the remainder of the escarpment was still protected from denudation 

 by submergence, the second fall Avould next display itself on a further 

 upheaval of the land, the river being thrown over a lower ledge of 

 hard limestone ; finally the land continuing to rise, a third cataract 

 would be caused over the hard quartzose sandstone, Avhich rests on 

 the soft red marl at Lewistown. These several falls would, at first, 

 each recede farther back than the one immediately below it, their 

 distance being greater or less in proportion to the slow or rapid 

 rate at which the land emerged, but they would all at length be 

 united into one fall, the uppermost limestone becoming thicker in 

 its prolongation up the river, and thus retarding the retrogression 

 of the highest cataract, while the two lower falls would continue to 

 recede at an undiminished pace, until each had in its turn over- 

 taken the uppermost. 



In describing the coaist sections of Massachussets, and in trans- 

 ferring our attention to the interior of Kentucky — localities already 

 rendered classic by American geologists and palaeontologists — 

 Mr. Lyell has placed before us a clear view of other leading points 

 of the changes which that great continent has undergone. 



The tertiary deposit at Martha's Vineyard, on the coast of Massa,- 

 chussets, had, indeed, been described by Professor Hitchcock, who 

 seeing the highly-inclined position of the beds, the great variety of 

 structure as well as colour of the strata, and the obscure casts of 

 shells which they contain, was much impressed with their apparent 

 similarity to the Lower Tertiary beds, or Plastic and London clay 

 of the Isle of Wight described by Mr. Webster. By a careful ex- 

 amination however of these strata, and by collecting a larger and 

 more varied suite of organic remains than was known to Professor 

 Hitchcock, Mr. Lyell has come to the conclusion, that so far from 

 being of the Eocene age, this formation is at most of no higher 

 antiquity than the iMiocene. This result has been obtained by 

 finding the teeth of several specimens of fishes which belong to species 

 obtained by Mi*. Lyell in the Miocene "Faluns" of Touraine, and 

 determined by Agassiz ; together with vertebrae, referred by Mr. 

 Owen to two species of whale, the teeth of a seal, and the skull of 

 a walrus ; an association which cannot fail to convince geologists 

 that the materials of this island, off' the coast of New England, were 

 accumulated at no very distant geological epoch. The high inclina- 

 tion of these party-ccloured sands, clay and conglomerates, and the 

 curvatures which some of them have undergone, probably through 

 great lateral pressure, are clear proofs that they have been power- 

 fully upheaved and dislocated ; whilst the gravel and boulder forma- 

 tion which covers their edges horizontally, compels us to conclude, 

 that the disturbed beds were submerged during the boulder period, 



