POSTGLACIAL FEATURES OF THE UPPER HUDSON VALLEY Q 



show characteristic wave work. A few chffs that have been seen 

 are indicated on the map. 



Three miles northwest of Mechanic ville a heavy bar Hes at four 

 corners, at the summit level for that place, 390 feet. Many beach 

 features, of which two cliffs are noted on the map, are seen northward. 



On the west side of the valley one of the most important and con- 

 spicuous beaches is found on the Glens Falls quadrangle, at the mouth 

 of the Hudson gorge and close to the east face of Palmsrtown 

 mountain. The Hudson delta at this locality has already been noted. 

 It was partly mapped by Woodworth (4, plate 13, page 144). He 

 maps the higher terrace as glacial. But three strong gravel bars 

 on the edge of the high terrace are positive evidence of open- water 

 wave work. The theoretic height of the marine plane is here 435 

 to 440 feet. According to the map contours, the upper of the 

 heavy bars is 440 feet. The lowest bar lies under the house of 

 Mr Richard Denton, at the end of the short road, at about 420 

 feet altitude. This beach continues south for over a mile, to the 

 next crossroad. 



Some fine bars and cliffs, somewhat below the summit plane, occur 

 east and north of Glens Falls. A mile northeast of Wilton, and 

 southeast of Mount McGregor, is a drumlin with bars across the top 

 at over 400 feet, the theoretic plane being there 420 to 425 feet. 



West and northwest of Saratoga the shore line is marked by 

 numerous cliffs, bare ledges and weak bars or spits, which are not 

 indicated on the map. One of the bare-rock spaces is the ** Cryp- 

 tozoon Ledge," which has been made state property in care of the 

 State Museinn. 



The writer has not systematically examined the shore lines con- 

 tinuously, but has found good beaches and shore features at numerous 

 points, amply sufficient to determine positively the initial water 

 level from New York City to Canada. It should be emphasized 

 that the absence of features expected at any locality, or even along 

 a considerable stretch of shore line, is not conclusive negative evidence. 

 Shore features are capricious and often lacking where most con- 

 fidently expected and where the fact of standing water is proved by 

 good features on both sides of the negative locality. On the other 

 hand, strong features are sometimes discovered where not expected. 



There are several reasons for the weakness of the summit features, 

 besides those already mentioned. The waters soon fell away from 

 the initial or stmimit plane, due to the rising of the land. The 

 amount of detritus in the grasp of the earliest water was relatively 



