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Scientific Geology. 



seem sufficient to lead every reasonable man to the conclusion, that 

 these grooves and furrows were produced by the large bowlders, 

 which now strew the surface, and exhibit in their rounded forms and 

 smooth surfaces, the marks of powerful abrasion. And since we 

 uniformly find these bowlders to the south and southeast of their 

 parent rock, how can we doubt that a mighty current of water has 

 sometime or other swept over the surface from the north and north- 

 west. It seems to me, that in regard to Massachusetts, the evidence 

 of such a deluge is complete ; and it is difficult to see how it could be 

 more conclusive. 



It is maintained by those geologists who account for all geological 

 changes by existing causes, acting as they now do, that most of the 

 stratum which I have described as diluvium, has been produced and 

 brought into its present state by the action of existing streams, rains, 

 frost, and other agents now in operation. But the simple fact that 

 the current must have had a southerly direction in every part of the 

 State, and has left traces of its action on our highest mountains, ren- 

 ders such a supposition, it seems to me, altogether untenable. For 

 how could rivers have risen so high ; or how, unless it were a single 

 river, not less than 200 miles wide, could the waters have produced 

 such effects 7 The same difficulty is in the way of supposing, as do 

 some fluvialists, that the land was once much lower than at present, 

 having been gradually elevated by earthquakes. Admit, if it be 

 wished, that the surface was once much lower than its present level : 

 the difficulty will still be to find a current 200 miles wide. 



Other geologists, who perceive the utter insufficiency of such causes 

 to account for diluvium, have imputed very much of it, and also dilu- 

 vial grooves and furrows, to the, retiring waters of the ocean, when 

 first the solid strata were elevated. I doubt not that such was the 

 origin of much of the diluvium that now covers the globe. But I 

 think it quite obvious that all the diluvium in Massachusetts, which 

 was produced by this and other causes, has been modified by a deluge 

 long subsequent to the elevation of our continent from the ocean. 

 For by examining the sections of our rock strata, appended to this 

 Report, as well as the map illustrative of the course of the same, it 

 will be seen that their prevailing dip is easterly, and their general 

 direction north and south. Hence the anticlinal line of these strata, 

 must be sought farther west than Massachusetts ; and, consequently, 

 the retiring waters must have rushed from the west at that epoch. 

 But the actual current of the last deluge came from the north and 



