628 H. L. FAIRCHILD POST-GLACIAL UPLIFT OF NEW ENGLAND 



at Killingly, and 285 to 290 at Putnam. At or above Putnam the gravels 

 will be found aggraded above the marine plane. 



The Willimantic and Xachaug rivers unite by the city of Willimantic, 

 which stands on the lower plains of the combined delta. The Xachaug 

 delta lies northeast of the city, where the railroad to Boston has a deep 

 cut in the gravel plain, contoured at 260 feet. On the west side of the 

 river the edge of the detrital filling lies along or just below Ash Street 

 for one and one-half miles. The junction of Ash and Jackson streets 

 is on the border of the plain, with altitude about 255 feet. The theoretic 

 marine plane is here 260 feet. 



1'he delta of the AVillimantic Eiver lies west of the city toward South 

 Coventry, where plains fill the entire width of the valley at about 270 

 feet. In the west edge of the city, by the cemetery, the plain is con- 

 toured at 260 feet. This district deserves careful study. 



AIOUXT DESERT, MAIXE 



In this study of recent change of land level Mount Desert has peculiar 

 interest because of the writings of Professor Shaler, and the eastern part 

 of the island has been examined. Xo one could reasonably appeal to 

 glacial waters on the steep coast, and standing-water phenomena are 

 positive proof of submergence. Because Professor Shaler carried sup- 

 posed wave-work to a height of 1,300 feet, it is apparent that discrimina- 

 tion in the study is necessary and the criteria should be considered. 



On rock hills, especially of crystallines like those of the island, wave- 

 work of brief submergence can not be conspicuous. The standstill was 

 not long enough at any level to allow benching in the rock, and any 

 fainter inscriptions are likely to be destroyed by the thousands of years 

 of exposure in the severe climate. On the hills the most probable evi- 

 dence of submergence is the rinsing effect of storm waves — the removal 

 of the glacial drift from the rock surfaces. Even this may be difficult 

 of determination, especially in the forest after frost-work has riven th^ 

 ledges and snow and ice and tree roots have dislocated and shifted the 

 loosened blocks. A safe criterion is the nature of the material. The 

 weathering produces angular material of the ledge rock, to be discrimi- 

 nated from glaciated and foreign stones. At high altitudes the atmos- 

 pheric work may denude the steeper slopes of all drift except larger 

 blocks, but the presence of boulders of such shape or position that 'they 

 could have been tumbled away by storm waves may be taken as proof of 

 lack of submergence. On the other hand, stretches of bare, level rock, or 

 areas with little slope, where some glacial stuff should lie if the area 



