148 



Scientific Geology. 



and shrubs have been cut away ; and in many places of great extent, 

 the surface is literally covered by these rouuded and erratic blocks, 

 " Thus must the world have appeared to Noah, as he came out of the 

 ark," exclaimed my travelling companion, as we came suddenly in 

 view of a wide landscape near Squam, in Gloucester, studded with 

 bowlders. The view is, indeed, a most singular one ; and cannot 

 fail to impress every reasoning mind with the conviction, that a del- 

 uge of tremendous power must have rushed over this cape. Noth- 

 ing but a substratum of unyielding sienite could have stood before its 

 devastating energy. The man who views this coast and that of Co- 

 hasset and Scituate, is no longer at a loss from what region the count- 

 less blocks of granite and sienite, scattered over the southeast part of 

 the State, proceded. 



As we proceed westerly from the coast and rise upon the higher 

 lands of Worcester County, the quantity of diluvium decreases; 

 though in many places very abundant. In general the higher parts 

 of mountains exhibit less of diluvial action than the lower regions. 

 But it is usually at an intermediate level, and neither upon the high- 

 est nor in the lowest places, that the greatest amount of diluvium is 

 accumulated. On steep and narrow mountains, we could not expect 

 that much of this stratum would be detained, even if we admit that 

 water could accomplish the Sisyphean labor of rolling rounded rock 

 masses up steep and lofty escarpments. And in the lowest grounds, 

 existing streams have to a considerable extent removed the diluvium, 

 and in some instances covered it up. But there is no mountain so 

 lofty in Massachusetts as not to exhibit marks of diluvial action. On 

 Wachusett and Saddle mountains, indeed, very few rounded masses 

 of rock from a distance are to be seen ; though their own surfaces 

 have been acted upon by a diluvial current, as I shall shortly state 

 more definitely in speaking of another part of this subject. On the 

 lower and less precipitous mountains of the State, however, bowlders 

 of huge size, as well as gravel and sand, are abundant. 



The valley of Worcester abounds in diluvium ; especially in the 

 north part of the county. Proceeding towards the Merrimack, 

 through Sterling, Lancaster, and Groton, we find large accumulations 

 of diluvial gravel, exhibiting the irregular convexities and concavities 

 already described. We find in this region, however, much, fewer 

 large bowlders than in most other parts of the State. These become 

 more numerous as we follow the Merrimack to its mouth. Much of 

 the diluvium, however, from Worcester to Newburyport, consists of 



