THE HADLEY LAKE BOTTOM. 675 



Because the eastern branch was deepest toward the north and rises and 

 widens to the south, it has given rise to a curious little drainage area, whose 

 smaller streams head in its southern higher portion and gather and run north 

 around the north end of Blount AVarner. 



An inspection of the map will show that the tail of the high terrace 

 carried out from ]\Iouut Warner is curiously directed southeast, another 

 indication of the greater force of the current through the passage to the 

 west of the hill. This tail is' carried south across the Northampton road. 

 Extending" across this road and much farther south to the base of the Holy- 

 oke range, is a broad, very flat plain, underlain by clays of great thickness, 

 which for a long way south are covered by only a thin layer of sand, so 

 that the whole rainfall over the area is kept verj^ near the surface, and the 

 brooks are large and run in very shallow beds. 



The groove mentioned above, worn by the waters parting- on Mount 

 Warner, seems to have been cut into the clays which had been previously 

 deposited to a higher level than the bottom of the groove over the area 

 where the latter was formed. This is especially clear where the Northamp- 

 ton road crosses the groove just west of Amherst and rises upon the plain 

 south of Mount Warner just mentioned. It goes up over the edges of the 

 horizontal clays to I'each this plain. Also, on the west side, the clays rise 

 at the south line of Hatfield 72 feet above the river level. This falls in with 

 many other indications that in the latter portion of the highest water stand 

 the eroding and carrj^ing activity of the stream was considerabl)^ increased. 

 Another similar indication is that over the lake bottom and in the high 

 terrace everywhere, and under every variety of circumstances, a coarser 

 stratum overlies finer beds as the last deposit of the flood time, as if the 

 final melting of the ice from this drainage area had come with some 

 suddenness. 



At the foot of Amity street another interesting observation and deduc- 

 tion may be made. Along the side of Mount Warner and its southern 

 prolongation, as well as along the slope of the Amherst ridge east of us, 

 the long sand bars are carried south just as they were left by the flood, 

 and they merge below with the broad, flat thread of the channel, it also 

 being just as it was left by the same current (barring, of course, the small 

 erosion of the brooks); and down both the slopes there is no intermediate 

 ten-ace or line of erosion to indicate anv intermediate water stand between 



