630 CHARLES EMERSON PEET 



present Lake Champlain. By greater northern uplift Lake Champlain 

 has been warped into the southern part of its basin, thus submerging 

 tlie lower Poultney-Mettawee Valley, dissevering its system, and 

 drowning the lower courses of its tributaries, including the South Bay 

 Creek, and numerous other streams in southern Champlain (see 

 Fig. 25, D, Fig. 20, and Fig. 21). 



The streams in northern Champlain did not have their courses 

 extended because of the uplift, for the outlet at the north controlled 

 the water-level. Their courses have been extended only by the 

 lowering of the water-level because of the cutting clown of the 

 outlet — an amount which Baldwin^ has placed at 50 feet, but con- 

 cerning which the writer has made no observations. Terraces lower 

 than those of Marine Champlain have been made in present Lake 

 Champlain and exposed to view by the lowering of the water-level 

 due to the cutting of the outlet. 



With this upHft, greater at the north than at the south, came the 

 revival of north-heading streams and the arrest in the development 

 of south-heading streams — a process which seems, from the topo- 

 graphic maps, to be well shown by East Creek, and by Dead Creek 

 and its south-heading tributaries. Revival seems to be shown by 

 the north-heading tributaries of Dead Creek. 



The rapid down-cutting of the Poultney-Mettawee River, because 

 of its steep northward gradient (120 feet in 14 miles, if the estimates 

 of elevations at the close of Marine Champlain time be correct) 

 surpassed that of most of its tributaries, which had neither the advan- 

 tage of the steep northward gradient (since most of them had either 

 an eastward or westward flow), nor had they the advantage of the 

 volume of water of the larger stream. Consequently these tributaries 

 were left to descend over steep slopes into the valley of the main 

 stream (see Fig. 16, A, p. 452). The larger tributaries have been 

 able to push this steep part of their" gradient farther back from the 

 main stream than the smaller ones. South-heading tributaries, 

 with the advantage of the steep gradient given by the attitude of the 

 land when the Poultney-Mettawee was cutting its channel, were 

 more successful in keeping pace with the cutting of their mains, but 

 since the northern uplift they have been arrested in the continuance 



I American Geologist, Vol. XIII (1894), p. 104. 



