CHAPTER IV. 



GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 



fHE Connecticut Valley district is separated from the rest of the 

 state by features mainly dependent upon geological structure. The 

 eastern border line is not the water-shed between the Connecticut and 

 Merrimack rivers, but the boundary between diverse systems of strata, 

 giving rise to agricultural and topographical peculiarities. This region 

 is limited northerly by the crossing of the valley by the Gardner Moun- 

 tain range, giving rise to the "Fifteen-miles falls," between Monroe and 

 Dalton, the river descending three hundred and seventy feet, or one hun- 

 dred feet more than from the falls to the Massachusetts line, a distance 

 of one hundred and thirteen miles in a direct course. The eastern bound- 

 ary follows the line between the Coos group and the Atlantic gneisses. 

 This usually conforms with the summit or eastern base of a mountainous 

 range of quartzite. The northern and western boundaries coincide largely 

 with the hydrographical boundaries as far south as the granite mountains 

 east of Montpelier, and then include the greater part of the calcareous 

 formations in eastern Vermont. These are narrowest by Mt. Ascutney, 

 opposite Cornish, so that a natural primary division of the area into two 

 parts is suggested by this constriction. 



The soils of this district are of three kinds : first, those on the fertile 

 meadows of the Connecticut and its principal tributaries; second, the 

 rich uplands of the calcareous districts, comprised chiefly within the 

 western side of the river, while constituting areas of variable size on the 



