6 



Economical Geology. 



few, they ought at least to be converted into manure, and spread again 

 over those higher regions around, from which, by slow aqueous 

 agency, they have been washed away. Very many of the most bar- 

 ren regions in the State, might, by this means, be clothed with fertility 

 and plenty. 



Diluvium. 



This occupies more of the surface in Massachusetts than any other 

 formation. It is not generally distinguished from alluvium: but it is 

 usually much coarser, being made up commonly of large pebbles, or 

 rounded stones, mixed with sand and fragments of every size, which 

 are often piled up in rounded hills to a considerable height ; and un- 

 der such circumstances, as preclude the probability that it could have 

 resulted from existing streams. Indeed, it is spread over the highest 

 mountains, wherever it could find a lodgment, and appears to have 

 resulted from powerful currents of water, which, in early times, swept 

 over the globe. 



In a scientific point of view, this is one of the most interesting for- 

 mations in the State ; and in the proper place, I shall exhibit several 

 facts respecting its relations and mode of occurrence. But in an 

 agricultural point of view, it is the least interesting of all our strata ; 

 for of all the soils, it is the most unfriendly to rich vegetation. And 

 as it is spread in a good measure over every kind of rock, it often 

 prevents the formation of a good soil, from the decomposition of the 

 rock. It is in general easily recognized in the most sterile places, in 

 the form of low rounded hills, composed almost entirely of coarse 

 pebbles^ or cobble stones, and sometimes larger rounded masses of 

 rock, called bowlders, mixed with coarse sand, and covered with a 

 stinted vegetation. It was evidently deposited by currents rushing vi- 

 olently over the surface ; since only the coarser materials, which were 

 driven along, were left ; while the finer particles were kept suspend- 

 ed by the agitation of the waters. Some varieties of this diluvium 

 may, indeed, be converted into a soil of tolerable richness by manur- 

 ing it abundantly, and clearing away the stones. And generally too, 

 the rains that have fallen on it for thousands of years, have conveyed 

 its finer particles to the bottom of the vallies and cavities, with which 

 this formation abounds, and these being mixed with much vegetable 

 decayed matter, a soil of good quality is formed. So that within the 

 limits of this formation much good land occurs. But these fertile 

 spots ought perhaps rather to be denominated alluvium than diluvium. 



