OLD RIVER BEDS. 

 II. IN ROCKS OLDER THAN DRIFT. 



215 



FIG. 102 (Jii.) 



All the preceding cases of changes in the beds of rivers have occurred during the allu- 

 A'ial period. We add others, which, like those at Bellows Falls, Brattleboro and Caven- 

 dish, are of far earlier date, and have been formed in solid rock. Some of them, indeed, 

 have no connection with existing rivers. 



1. The case just referred to at Bartonsville furnishes an example. For the old bed of the river, being 

 filled with sand and gravel probably during the sojourn of the land beneath the sea, compelled the stream, 

 on the rise of the continent, to cut out a new channel through the rocks, which it abandoned, when, by the 

 help of the railroad, it was able to scoop out its old bed. 



2. On the Quechee River at Hartford the river passes through a gorge a mile long, one side of which is a 



continuous wall one hundred feet high. A mile above the 

 gulf are falls twenty feet high, with pot-holes, and probably 

 the river has worn back that distance. This gulf has been 

 supposed to follow the course of a trap dike.But Fig. 102, bis, 

 will show that the dike crosses the river. 



3. In Shrewsbury, near Cuttingsville. One of our number 

 (A. D. Hager) thus describes this example : "About two 

 miles north of Cuttingsville is an old river bed now occupied 

 by the railroad. It is in Shrewsbury, near the west line. 



The length of the old bed is about three quarters of a mile. The river now runs through a deep gorge in 

 slaty rock, seventy-five feet deep in some places. Terraces abound at the side of the gorge near where the 

 old bed is situated." 



4. In Clarendon. This occurs on Mill Brook, a branch of Otter Creek, a little east of the Western Ver- 

 mont Railroad near the principal village. The stream has cut 



a gorge through the rock eighty-five feet deep, and three old 

 beds can be traced, as is shown on the sketch Fig. 103, furnished 

 by A. D. Hager, who alone of our number has seen this case. 



5. In the east part of Pittsford, we were carried to an old 

 river bed by B. F. Winslow, Esq. It lies on the west face of 

 the steep mountain sometimes called East Peak, a mile or two 

 east of the iron furnace on Furnace River. The gorge is on 

 the west face of this steep mountain, about six hundred feet 

 above the river, and half a mile long, running nearly north and 



south. The north end opens into the valley of Furnace River, somewhat east of the spot already described 

 for its remarkable exhibition of powerful denuding agencies, and the south end opens into the same valley. 

 It is in fact a gorge two or three rods wide, and from thirty to one hundred feet deep, cut into the hard quartz 

 rock of this peak, which is a projection from the higher range to the east, that has withstood all denuding 



agencies and preserved this remnant of an 

 old river bed, probably the bed of Furnace 

 River, when it was six hundred feet above 

 its present level. The sketch in Fig.104, B, 

 which is a section crossing this mountain and 

 the gorge, east and west, will give an idea 

 of its position. When occupied by the 

 stream as it must have been for an im- 



Oid River Bed, Pittsford. mense period to wear out a channel proba- 



bly once a hundred feet deep throughout, 

 in a rock which bids defiance to almost all agencies, the broad valley to the west, now at least six hundred 



Fio. 103. 



In Clarendon. 



Fio. 104. 



