142 B. S. Tarr — Central Massachusetts Moraine. 



scribed by various observers. It seems to be established that 

 this moraine marks the point of the glacier for the greater part 

 of its long stand upon this part of the continent. Patches of 

 morainal matter have been noticed and described from various 

 parts of New England, by Mr. Upham and others, but no con- 

 tinuous lines of moraine have been traced for any considerable 

 distance. Some of these morainal patches have been supposed 

 to mark local glaciers remaining upon the higher lands after 

 the main ice mass had disappeared. 



A singular morainal area was described by Prof. Shaler in 

 the Ninth Annual Report of the U. S. Geological Survey, as 

 occurring at Cape Ann on Massachusetts Bay. As an assistant 

 in this work my attention was called to this deposit several 

 years ago and its boundary within the area was traced with 

 considerable accuracy. At that time it was not known that 

 this bit of moraine was connected in any way with any other, 

 but subsequent studies of the glacial deposits have pointed to 

 a somewhat continuous moraine from Cape Ann nearly to the 

 Connecticut River. Beyond the Connecticut morainal deposits 

 have not been identified with certainty, excepting in some of 

 the larger stream valleys ; and the connection of these ap- 

 parently isolated moraines with the Central Massachusetts 

 moraine has not been definitely established. 



The Cape Ann moraine has been fully described by Prof. 

 Shaler,* with numerous illustrations from photographs. In 

 general it occupies a large part of the island of Cape Ann and 

 of the mainland to the west and southwest. On the island it 

 covers the major part of the interior, but is rarely found in 

 perfect development below the one hundred foot contour line, 

 this part of the island being chiefly bare 'bed rock as if wave- 

 swept. The morainal boundary is roughly circular, with an 

 average diameter of not more than four miles. It is completely 

 separated from the moraine on the mainland to the westward 

 by the inlet or "reach" of "Squam River," but above the one 

 hundred foot contour line it begins again occupying a wooded 

 strip, with a width of from one to four or five miles, in the 

 towns of Manchester, Essex and Gloucester. Farther still to 

 the west the moraine becomes narrower but is distinctly trace- 

 able in the vicinity of Chebaeco Pond, Wenham, and farther 

 west to the extreme boundary of the Salem sheet of the Mas- 

 sachusetts topographical atlas. 



This band of moraine is twenty miles long, and the width 

 varies from a few hundred yards west of Wenham to four or 

 five miles east of that town. The average width is not less 

 than a mile. Prom the western part of the Salem street to 



* Ninth Annual Report U. S. Geol. Survey, pp. 529-611. 



