Diluvium. 149 



shingle. ; by which, I mean partially rounded fragments of slate ; that 

 being the predominant rock. 



On the south of Worcester, the region of country sloping towards 

 the Blackstone, especially on the west side of the river, exhibits strik- 

 ing traces of diluvial agency. In some places, as in Uxbridge, the 

 bowlders of gneiss are large and numerous. As we proceed towards 

 Providence, this stratum becomes thicker ; concealing, indeed, nearly 

 all the rocks in place ; and in the vicinity of Providence a large pro- 

 portion of sand is mixed with the gravel. This proceeds from the 

 tertiary formation which occurs near Providence, as well as in the 

 southeast part of Massachusetts, and which has been torn up in many 

 places by the action of water. The sand abounds on the west shore 

 of Narraganset Bay, nearly the whole distance to Newport. 



The valley extending south from Oxford through Webster into 

 Connecticut, contains, especially on its slopes, an abundance of dilu- 

 vium : so thick a coat, indeed, that the rocks in place are in a great 

 measure hid ; and hence it is quite difficult to ascertain the bounda- 

 ries of the different formations. 



Between the Worcester and Connecticut valleys, the country is 

 mountainous ; with deep and interrupted valleys, whose general di- 

 rection is north and south. In some of these valleys the gneiss rock 

 is covered for miles by diluvium, and by alluvium of disintegration. 

 Indeed, this is often the case, in the more elevated parts of this re- 

 gion ; though the diluvial waters seem to have exerted less power 

 here, than in the lower land in the eastern part of the State. 



The level part of the basin of the Connecticut, exhibits less strik- 

 ing marks of diluvial action than the smaller elevations on the margin 

 of this tertiary plain. Some might even doubt whether the tertiary 

 deposite of this valley is not postdiluvian. But I think that upon the 

 whole, marks of diluvial action are too strong on its surface to be 

 referred to the currents of an ancient lake. For the diluvial coat is 

 several feet thick in almost every place. We could not expect that a 

 general deluge, of depth sufficient to rise above our highest moun- 

 tains, would act as powerfully upon low and broad plains, as in the 

 vicinity of mountain defiles and gorges, through which the water 

 must have rushed with great power, even though its general move- 

 ment was moderate. And this view accords with the present dispo- 

 sition of diluvium in Massachusetts. In Bernardston, Franklin 

 county, for instance, which lies at the northern extremity of the Con- 

 necticut valley, we find a large amount of diluvium, which was evi- 



