340 Scientific Geology. 



Worcester and Merrimack Vallies. 



Direction. Dip. 



Webster, N. and S. 45 West. 



Ward, N. and S. 70" to 80 West. 



Worcester, west of hill of granite, N. and S. 25 West. 



Do. east of the same, various, 25 to 90 Easterly. 



From Worcester to Berlin, N. E. and S. W. 20 to 90 N. W.? 



Sterling, N. several degrees E. 60 to 70 West. 



(This last is the most usual dip of this range of mica slate.) 

 Leominster, N. several degrees E. West, large. 



Fitchburg to Lunenberg, do. 10 to 30 Easterly. 



Between Lunenberg and Shirley, do. Westerly, small. 



Boxford, N. E. and S. W. 25 to 50 N. W. 



Groton, do. 30 to 45 S. E. 



Pepperell, do. nearly 90 N. W. 



Townsend, N. and S. 30 to 60 East. 



Andover, E. and W. 70 to 90 North. 



Methuen, (Falls,) E. and W. 20 to 30o North. 



Tyngsborough to Dunstable, Southeast. 



Methuen to Dracut, Northwest, large. 



Lowell to Chelmsford, nearly E. and W. do. 



Between Newburyport and Bradford, do. Northerly. 



There would seem from the above statement, to be great irregular- 

 ity in the direction and dip of the strata of this range. Yet it must 

 be recollected, that I was careful to notice all the important anomalies 

 in these respects, that fell under my observation ; while I made few 

 records where the usual dip and direction were observed. Hence the 

 statement above made, in respect to the usual dip and direction, may 

 be true, although not taught by the preceding table. And the same 

 remarks are in a measure applicable to other rocks. To prevent any 

 false inferences from such statements, I have drawn the map which 

 exhibits the predominant direction, and the sections appended, which 

 exhibit the predominant dip, of the strata anomalies being neglect- 

 ed, unless they are of considerable extent. In the range under con- 

 sideration these inequalities are somewhat numerous. Yet I am in- 

 clined to the opinion that the mica slate along the western border of 

 this range, is connected with that system of stratification which is ex- 

 hibited by the great body of the gneiss in the western part of Wor- 



* Plates XV, XVII, and XVIII. 



