of the Northern Catsklll Mountains. 161 



map. This was not visited, but it seems reasonably safe to 

 assume that it, too, is a delta. 



Deltas along Batavia Kill. — One half mile north of Ash- 

 land village, in West Hollow, is a beautiful delta standing at 

 about 1600 feet. The stream has destroyed a considerable part 

 of it by cutting through the middle, but remnants are pre- 

 served on either side. It has a distinct lobale front of fine 

 gravel and sand. The top is generally fairly level, though one 

 part near the front rises slightly higher than the part behind. 

 The up-stream part of the mass appears to be morainic. 



Just east of the village of East Ashland, at the mouth of the 

 first valley comiug in from the north, is a fiat-topped deposit of 

 fine gravel and sand between 1580 and 1600 feet, which is 

 interpreted as a delta built into Grand Gorge Lake. The 

 material constituting the terrace was beautifully exposed in 

 1913 in a cut near the junction of roads. A moraine on the 

 north side of this deposit seems to cross the north-south valley 

 as if formed by an ice tongue coming down the Batavia Kill 

 from the direction of Windham. The delta, if such it be, 

 seems to be later than the moraine. A part of the flat-topped 

 gravel mass is, for some unexplained reason, partially isolated 

 from the remainder. 



The Delta at Windham. — One of the finest of the deltas 

 built into Grand Gorge Lake is found at Windham at an ele- 

 vation between 1580 and 1600 feet. On the south side of the 

 valley the flat-topped terrace extends conspicuously for fully a 

 mile. On the north side, just north of the road in the western 

 end of the town, the terrace is well developed. The fine gravel 

 composing it is well shown in several cuts. 



The eastern end of this delta is open and morainic, and seems 

 to be an ice-contact front. Its nature is well brought out in 

 the photograph (fig. 13) which shows the irregular morainic 

 and slump topography in the foreground and the flat-topped 

 delta terrace clinging to the opposite hillside, but finally wedg- 

 ing out up stream. Just at the right of the picture the stream 

 enters a narrow valley which it has cut through the main part 

 of the delta. These relations are taken to mean that, at the 

 time the delta was building, a lobe of ice pushing through the 

 gap at East Windham, or possibly originating locally in the 

 high mountains at the head of Batavia Kill, extended down to 

 this point. It is difficult to see how, if this were not the case, 

 the flat-topped delta could have been produced without the 

 lower, open depression behind becoming filled. 



The heights of the delta tops thus far described bear an inter- 

 esting relation to each other. The one opposite Grand Gorge 

 and that on the Platter Kill have, as nearly as can be determined 

 from the topographic maps, elevations of 1620 feet. That at 



