288 Basin- like Plains of Chile. part n. 



ing low represented water,) and the creeks and fiords 

 now intersecting the southern and western shores of 

 the continent. We can on this view of the sea, when 

 the land stood lower, having long and tranquilly 

 occupied the spaces between the mountain-ranges, un- 

 derstand how the boundaries of the separate basins 

 were breached in more than one place ; for we see that 

 this is the general character of the inland bays and 

 channels of Tierra del Fuego ; we there, also, see in 

 the sawing action of the tides, which flow with great 

 force in the cross channels, a power sufficient to keep 

 the breaches open as the land emerged. We can 

 further see that the waves would naturally leave the 

 smooth bottom of each great bay or channel as it be- 

 came slowly converted into land, gently inclined to as 

 many points as there were mouths, through which the 

 sea finally retreated, thus forming so many water-sheds, 

 without any marked ridges, on a nearly level surface. 

 The absence of marine remains in these high inland 

 plains cannot be properly adduced as an objection to 

 their marine orio-iD : for we mav conclude, from shells not 

 being found in the great shingle beds of Patagonia, 

 though copiously strewed on their surfaces, and from 

 many other analogous facts, that such deposits are 

 eminently unfavourable for the embedment of such 

 remains ; and with respect to shells not being found 

 strewed on the surface of these basin-plains, it was 

 shown in the last chapter that remains thus exposed in 

 time decay and disappear. 



1 observed some appearances on the plains at the 

 eastern and opposite foot of the Cordillera which are 

 worth notice, as showing that the sea there long acted 

 at nearly the same level as on the basin-plains of Chile. 

 The mountains ' on this eastern side are exceedingly 

 abrupt ; they rise out of a smooth, talus-like, very 



