ooO ILLOGICAL GEOLOGY. 



Earth, there are at this moment being prodaced an im- 

 mense number of strata differing from each other in litho 

 logical characters. Xame at random any one part of the 

 sea-bottom, and ask whether the deposit there taking j^lace 

 is hke the deposit taking place at some distant part of the 

 sea-bottom, and the almost-certainly correct answer will be 

 — Xo. The chances are not in favour of similarity, but 

 very greatly against it. 



In the order of superposition of strata there is occur- 

 ing a like variety. Each region of the Earth's surface has 

 its special history of elevations, subsidences, periods of 

 rest ; and this history in no case fits chronologically with 

 the history of any other portion. Kiver deltas are now be- 

 ing thrown down on formations of quite different ages. 

 While here there has been deposited a series of beds many 

 hundreds of feet thick, there has elsewhere been deposited 

 but a single bed of fine mud. While one region of the 

 Earth's crust, continuing for a vast epoch above the surface 

 of the ocean, bears record of no changes save those result- 

 ing from denudation ; another region of the Earth's crust 

 gives proof of various changes of level, with their several 

 resulting masses of stratified detritus. If anything is to 

 be judged from current processes, we must infer, not only 

 that everywhere the succession of sedimentary formations 

 differs more or less from the succession elsewhere ; but also 

 that in each place, there exist groups of strata to which 

 many other places have no equivalents. 



With respect to the organic bodies imbedded in forma- 

 tions now in progress, the like truth is equally manifest, if 

 not more manifest. Even along the same coast, within 

 moderate distances, the forms of life differ very considera- 

 bly ; much more on coasts that are remote from each other. 

 Again, dissimilar creatures that are living together near the 

 same shore, do not leave their remains in the same beds of 

 sediment. For instance, at the bottom of the Adriatic. 



