228 H. L. PAIRCHILD PLEISTOCENE MARINE SUBMERGENCE 



Terraces in the Hudson-Champlain Valley. — Terraces are displayed 

 in the Hudson and Champlain Valley on even a larger scale than in the 

 Connecticut Valley. They are more conspicuous in the latter valley and 

 for longer distances because of the narrowness of the valley and the 

 smaller size and closer grouping of the benchings. In the Hudson-Cham- 

 plain the terraces usually do not lie grouped within the range of close 

 vision. 



A remarkable benching of detrital deposits is exhibited in the Hudson 

 Valley from Troy north to Glens Falls. Into this stretch of 45 miles of 

 sealevel water five rivers poured their glacial flood — the Mohawk, Hoosick, 

 Anthony Kill, Fish Creek, Batten Kill, and the upper Hudson. An 

 enormous volume of detritus was swept into the slowly falling waters of 

 the marine inlet. Wave and current action combined, working at succes- 

 sively lower levels on the deposits, produced a display of terraces on a 

 large scale. For illustration the reader may look at the Cohoes, New 

 York, topographic sheet. The terraces of the Hoosick delta shown on 

 this sheet have been discussed and figured by Professor Woodworth in 

 Kew York State Museum Bulletin No. 84, pages 134, 200, and plate 24. 



Perhaps the finest example of terraces, and comparable in ever)^ way to 

 the Connecticut Valley features, is found on the delta of the Winoosld 

 at Burlington, Vermont, and up the Winooski Valley as far as Mont- 

 pelier. On the Burlington sheet the terraces are shown at all levels from 

 Lake Champlain (100 feet) up to 500 feet. The reader might claim 

 that these are river-made terraces, since they lie in the river valley and on 

 its delta. This is not true. There was another agent involved. We 

 know that oceanic waters occupied the Champlain and Winooski valleys 

 when these elevated deposits were made. The writer finds clear evidence 

 of the standing waters up to height of at least 640 feet on the parallel 

 of Burlington. The Winooski delta was built in the open waters of the 

 great Champlain Valley, and the splendid display of terraces was carved 

 in the subsiding static waters by the combined work of waves and cur- 

 rents. The sealevel waters extended southeast up the narrow Winooski 

 T^alley to beyond Montpelier, and the terracing of deposits on the valley 

 walls are abundant and conspicuous, like those in the upper Connecticut 

 Valley. We have in the Winooski features a record of the same history 

 as in the Connecticut Valley: a narrow valley, deeply flooded with sea- 

 level waters, abundant inwash of detritus by tributary streams, and the 

 benching of the deposits by wave erosion and gentle currents, due to the 

 slow outflow of the lowering waters. The action was not that of a river, 

 but of an "inlet." 



