286 NEW RED SANDSTONE FORMATION. 



like an extensive formation. We are therefore driven to the conclusion, that 

 there were at one time extensive tracts of land of primary formation where now 

 is nothing but sea. And it almost seems as if in the lapse of time a nearly total 

 change of sea and land has taken place. If a chief portion of the Continent was 

 once the bed of the sea — of which we think there is undoubted evidence — and 

 if also a chief portion of the continent of North America was once and probably 

 at the same geological era similarly situated, why may there not in the Atlantic 

 Ocean, which now rolls its vast waves uninterruptedly from continent to con- 

 tinent ? Why may there not have been large islands and tracts of land with 

 their mountains, hills, vallies, and other phenomena, which have been worn away 

 and destroyed by the powerful action of the elements which then, in all pro- 

 bability, acted with much greater intensity than now ? And at the time the 

 present dry land was gradually being raised from below the level of the sea, 

 other portions of the earth's surface may have as gradually been subsiding ; of 

 the one we have positive evidence, but of the other we can only have, from the 

 nature of the case, negative evidence. 



Immediately prior to the deposition of the New Red Sandstone formation, 

 extensive and sudden changes seem to have taken place with respect to the then 

 relative position of the sea and land. The sea seems to have acted on the land 

 with great turbulence and violence, and the turbid and muddy waters have 

 deposited with considerable rapidity the lower beds of the New Red Sandstone 

 formation. Under circumstances of this kind, where we find the hardest rocks 

 have been ground down into fine debris, there is little or no probability that 

 there would be any preservation of the delicate fabric of organized beings ; not 

 but that they may have been fully as abundant then as they were both before 

 and subsequently. The waters seem to have acted with irregular degrees o: 

 violence, often coming apparently in floods or flushes, bearing with it a quantity 

 of stones and pebbles, and then depositing upon these latter finer materials, as 

 may be seen most frequently in the strata of the New Red Sandstone, in quarries 

 and other localities, where the lower part of a stratum will be a kind of con 

 glomerate, and the upper part of it a fine-grained Sandstone. Sometimes the 

 water would come with such force as to work up what had already been deposited, 

 and redeposit it, so that we have pebbles of the New Red Sandstone itself, ai 

 well as pebbles of the older rocks occurring in its strata. At other times the 

 rock has been deposited so finely that it is laminated in seams almost as thin as 

 the leaves of a book ; in this case the pebbles are rare and very small. There 

 would also, no doubt, be partial eddies and currents of water, accompanied with 

 smoothness and stillness, to which may be owing the minute and fine grained 

 appearance of the rock in some places. In many strata of the New Red Sand 

 stone may be traced ripple marks precisely the same as those which are formed 



