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Geological Observations^ — 1. On Alluvial Rocks: 2. On For- 

 mations: 3. On the Changes that appear to have taken 

 place during the different periods of the EartV s formation 

 on the Climate of our Globe, and in the nature and the phy^ 

 sical and the geographical disti'ibution of its Animals and 

 Plants. By A. Boue', M. D. Member of the Wernerian 

 Society, &c. Communicated by the Author. 



I. — On Alluvial Rocks. 



1. Old Alluvium y syn. Diluvium. 



jL his series of alluvial deposits, in the regular succession, 

 immediately follows the newest tertiary rocks. We do not be- 

 lieve that it is always distinctly separated from the modern al- 

 luvium, although Cuvier, Professor Buckland and others, main- 

 tain that such is the case. When a distinct separation takes place, 

 it only occurs accidentally here and there. On the contrary, there 

 is in general a transition from the one to the other, as in all the 

 preceding formations ; so that the two would seem to be nothing 

 else than the product of the same and still existing causes, al- 

 though the effects of these causes would appear to have dimi- 

 nished from the older to the more recent epochs. When both 

 alluvia are well separated, it indicates that the causes to which 

 the old alluvium has owed its existence had suddenly ceased to 

 operate. Thus, in a great basin, it would be thought that the 

 water has rapidly subsided by a rupture or debacle, &c. 



In this deposit we find remains of vegetables still existing ; 

 also of marine, fluviatile, and terrestrial shells, of species still 

 living ; likewise remains of extinct and living quadrupeds, but 

 no human bones. 



Old Deposites of the Sea. 



Accumulations of sand^ rolled stones^ and decayed vegetables^ along the coast, 

 more or less elevated above the present level of the sea, at high-water, 

 (Britam). 

 Banks of sand and shelly marl, with bones and remains of marine animals, 

 (East coast of England, Forth, Clyde, Norway, Oyster Bank near Ro- 

 chelle, and at the mouth of the Gironde, Boston in the United States). 

 Sandy calcareous matter deposited by the sea, in holes and fissures in 

 calcareous rocks of the Mediterranean ; compact limestone, with 

 still existing marine shells (Nice), Mediterranean of M. Risso. 



