646 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



of the roadways are the resuh, of subsequent excavation, and that the sui'face 

 is changed by grading north of Walker Hall and the Octagon. 



Through this passage between Mount Pleasant and Pikes Peak there 

 was a steady set of the current which has built up the broad area of finely 

 washed and sorted gravels which stretch across and down through the pass 

 and which are well exposed all round the Catholic Church. Southeastward 

 they stretch as a flat of finer sands, with a layer of concentration gravel 

 capping it, across from Professor Tyler's hill to College Hill. The two stone 

 churches and the high-school building are on this sand plain. College 

 street lies so near its border that the houses on the north side have cellars 

 in sand; those on the south side have wet cellars, as they cut through the 

 thin border of the sand and get the drainage which comes down from the 

 College Hill on the surface of the impervious till beneath. 



The current swept the sands across in a line from the Catholic Church 

 to the hiofh-school buildino- and the common. An area in the recess of the 



CoUegeHOL. s 



~^ CentraZMR.. 



TUT :_.._^_.-^_^....« 



Fig. 37.— Section of shore beds of Hadley Lake south of College Hill, at Amherst. The cutting was 18 feet deep. 



L-shaped island, the south half of the common, was not filled up quite to 

 the true level and was underlain by till at no great depth, and so was orig- 

 inally a very swampy place. It has been filled in considerably, and along 

 most of the street to the east and the whole of the street to the west of it 

 the artificial filling has been so great that the waterworks ditches did not 

 reach the undisturbed sands. 



Along the whole west side of the L-shaped island the level of Lincoln 

 street is the level of the high terrace. It is a bench cut in the till, very 

 broad, and but little covered by sands, since all that the main stream 

 obtained from the delta of Cushmans Brook was swept in across the village 

 to the East Street basin. 



Thin cappings and bars of sand are applied to its surface and to the slope 

 down to the lake bottom, and can be well studied from the side of Mount 

 Warner. Along Lincoln street the cuttings of the waterworks struck till 

 for more than half the distance, and along every street which crosses this 



