SOME RIVERS OF CONNECTICUT. 379 



and faulting, or whether these deformations were so slow in their 

 movement that the rivers persisted in spite of them. It may have 

 been that the larger rivers were victorious, while the smaller 

 were conquered and compelled to assume new consequent 

 courses. Whatever was their origin there must have been 

 abundant opportunities during the long erosioH which resulted in 

 the Cretaceous baselevel, and again in the period of revived and 

 quickened degradation succeeding the post -Cretaceous uplift, 

 for the streams to adjust themselves in a large degree to the 

 geological structure. The contrast of hard and soft beds and the 

 great elevation must have been potent factors in bringing to pass 

 such a result. We expect to find the streams so far re -adjusted 

 as to render improbable the discovery of their manner of origin. 

 The Housat07iic, a re-adjusted streatn. The best example of 

 re- adjustment is found in the northwestern part of the state 

 where the Housatonic and some of its branches follow well ad- 

 justed courses. From its headwaters, near Pittsfield, Mass., to 

 New Milford, Conn., it has nearly all the way chosen its course 

 along the Cambrian crystalline limestones in preference to the 

 harder granites and gneisses on either side. The stratigraphical 

 relationships of the limestone are not fully understood, but they 

 seem to be deeply eroded anticlines and synclines, whose axes 

 plunge north or south at various angles. The course of the 

 river, if the drainage was consequent, was at first along the 

 synclinal valleys, passing from one to another across the lowest 

 points in the anticlinal ridge between them. But by a series of 

 changes^ resulting from the differential rates of erosion as hard 

 or soft beds became exposed, the river previously to the Cretaceous 

 baseleveling, seems to have re -adjusted its course to the softer 

 limestones. However, there are several places where this con- 

 formity to structure does not seem to be the law ; where the 

 river departs from a limestone valley to flow for a time in the 

 crystallines, only to return to the limestone again. The most 

 marked instance of this is in the towns of Sharon and Cornwall, 



' " Rivers and Valleys of Pennsylvania," Davis, W. M., published in The National 

 Geographic Magazine, in 1889. 



