SOME RIVERS OF CONNECTICUT. 39 1 



seaward over the unconsolidated Tertiary deposits of the coastal 

 plain. As the plain of these recent deposits emerged from the 

 sea, the rivers were forced to extend their courses eastward over 

 the freshly raised surface to the retreating shore line. The 

 Scantic river has a similar history. Its upper course in south- 

 ern Massachusetts on the crystalline plateau is a remnant of 

 the drainage established before Cretaceous baselevelling and 

 revived by the subsequent uplift. How much that revived drain- 

 age has been modified by drift can only be determined by long 

 field study, but the topography, as read from the topograph- 

 ical atlas would seem to indicate, that it has not been much. 

 The valleys were undoubtedly clogged with drift, and the drain- 

 age area may be somewhat modified, but the drainage seems to 

 be substantially along the same lines. 



Just below the village of Hampden, the Scantic leaves the 

 plateau and enters the Triassic lowland. From this point to its 

 mouth at the Connecticut, opposite Windsor, a distance of 

 twenty miles, it flows nearly all the way through the gravel, 

 sand and clay deposits of the period of ice -retreat. The topog- 

 raphy of the lower course of the river is entirely characteristic 

 of a stream which has recently attacked a level, easily eroded 

 district. The inter -stream surfaces are broad and flat; the 

 descent to the stream bed which is sunk seventy or eighty feet 

 below the general surface is exceedingly steep. These two lines, 

 that of the inter -stream surface and that of the valley side, meet 

 at a sharp angle. The side streams are as yet very short, and 

 have cut narrow gorges down to the main river. Tributary to 

 them are deep side ravines, whose bottoms ascend rapidly to the 

 inter -stream surface, the whole making a dendritic system of 

 drainage in its earlier stages. The Scantic, having reached base 

 level in its lower course, has developed a narrow flood -plain. 



Manifestly this part of the river valle}' is of much later date 

 than the upper part. If, during the period of ice -retreat, the 

 lower Connecticut valley was an estuary, the Scantic was a much 

 shorter river than at present. Its mouth could not have been 

 far from the point where now it leave the cr3'stallines, but as the 



