84 BULLETIN OF THE ESSEX INSTITUTE. 



Loess-like cover. — The sand-plains as well as the till of 

 New England frequently bear a capping of fine loamy 

 sand of loess-like consistency and further resembling loess 

 in that the material is devoid of stratification ; it stands 

 up a longtime in steep cuts, and appears to owe its origin 

 to the blowing of dust in the post-glacial epoch. In 

 places, the material appears to be in process of accumula- 

 tion by depositing between the grasses so that the sod grows 

 upward according to the rate of accumulation of dust. 

 The underlying subsoil exhibits traces of decayed plants 

 in roots and occasional branches which have been buried 

 in the development of the deposit. This loess-like cover 

 is conspicuous in low places in the sand-plains where it 

 constitutes a sheet from a few inches to two or three feet 

 in thickness. It may frequently bo found at the foot of hills 

 on terraces or plains. Deposits of this loess, on the 

 southern part of Prudence Island, are from three to four 

 feet thick where not recently removed by the winds. 



This loess-like cover has much to do with producing the 

 level of some of the wash-plains as it has also with the 

 smooth flowing contours of the knob and basin type of 

 drift deposits. It is largely, I believe, the product of 

 post-glacial eolian action and this view finds support in the 

 common occurrence of sand-blasted pebbles on the sur- 

 face of wash-plains in close connection with the loess-like 

 cover. 



The deflation of the wash-plains does not usually result 

 in the formation of dunes. The sands which are coarse 

 shift somewhat to and fro with the stronger winds, but the 

 prevailing direction of transportation is eastward, at least 

 near Boston, for the reason that the easterly winds strong 

 enough to move the finer sands are usually so damp as to 

 cause the sands to cohere by reason of the films of water 

 which coat the grains. The dr}^ westerly winds alone 

 eflect the removal of dust. 



