CHAPTER VII. 



the different formations, 8fc. Hitherto, Geolo- 

 gists, in giving a description of the different materials 

 that enter into the composition of the globe, and also 

 of its formation, have pretty much confined their views 

 to two grand divisions, (viz.) the primitive and secon- 

 dary; the first of these having a reference to such 

 rocks as are destitute of organick remains ; and the 

 last, to such as are composed in a greater or less de- 

 gree of organick remains. In these, the subject of 

 alluvial deposites, which is in itself, to a certain de- 

 gree, a formation, is left entirely out of view, or if 

 taken notice of, it is in connexion with all secondary 

 formations. But in a careful examination of the sub- 

 ject, I can see no impropriety in considering it as a 

 distinct formation, and as justly entitled to the appel- 

 lation of ternary, as the latter of the other two, to that 

 of secondary. 



The idea of alluvial formations or deposites being 

 considered as a third or ternary formation, and dis- 

 tinct from the other two, may be objected to on the score 

 of its being, in general, made up of materials already 



