GEOLOGICAL AND MINERALOGICAL NOTES 75 



river bends abruptly north-northeast, but following the 

 upward course of the river the sand piain spreads out across 

 the city of Lawrence and the eastern part of South Law- 

 rence and in a southerly direction, following up the valley of 

 the Shawsheen river to Haggett's Pond and extending into 

 Middlesex county. By Consulting the geological map 

 of Essex County it will be seen by following this course 

 that this sand piain, in pre-glacial times, must have been 

 continuous and have occupied the larger part of the cen- 

 tral portion of Essex County. 



The drumlins of Prospect Hill in Rowley, Jewett's, 

 Turkey and Town hüls in Ipswich, were apparently de- 

 posited on this ancient sand piain, as remnants of it are 

 seen in deep beds to form a nearly complete circle around 

 their bases and the slight dip away from the drumlins is 

 a decided argument in favor of this theory. There are 

 also numerous kames and eskars of stratified sand and 

 gravel that are similarly resting upon the remnants of the 

 sand piain in South Groveland and North Andover. Ips- 

 wich Town Hill is an especially characteristic example of 

 a glacial lj.il! or drumlin deposited upon the sand piain. 

 On the northwestern part of the hill near High street, 

 there is a deep section from which the sand is being re- 

 moved shovving the dip of the beds of sand and giving a 

 section well up under the hill nearly to the one hundred 

 foot contour line, and in a northeasterly direction about 

 fifty feet above, there is a good section of the drumlin 

 (opened for gravel) showing the unstratified boulder tili. 

 Similar exposures of the sand are seen the whole length 

 of High street, north and south and down East street the 

 length of the hill. Other large exposures of the sand 

 cropping out here under the hill are seen on the northeast 

 and north side of this hill, thus making a nearly complete 

 circle around its base. Turkey Hill is also encircled by 

 this sand but the exposures have not been worked into to 

 the same extent. 



