GEOLOCJICAL OUTLINM 



17 



C(nintY fdnns a stron<«- contrast to that west oi' the river, and is an area of 

 transition to the much simpler strueture of Worcester County. Meta- 

 morphism and the part taken by i)Ost-Carboniferous eruptives increase 

 rej^-ularly eastward. Such rocks are wantinj^- in the first <'olunm and in 

 the western half of the country covered by the second, in the eastern half 

 of the latter the gi-anites begin and rapidly become iniportant; in the second 

 other rocks are associated, and in the area of the last colunm thev cover 

 more than half the surface. In a column devoted to the Massachusetts 

 coast region eruptive rocks would be still more predominant. 



General section showimj correlation of rocks in Massaclinsctts. 



[TLe names given in the second and third columns are those used in this monograph, Those iu the fourth column will be 

 used in a forthcoming memoir on the geology of Worcester County.] 



MON XXIS 2 



