308 THE GLACIAL LAKE AGASSIZ. 



tlie middle of the west side of section 31, towusliip 129, range 48. At the 

 latter locality it is a low, wave-like ridg-e of sand and fine gravel, abont 

 1,060 feet above the sea. On the south it is bordered by land 3 to 5 feet 

 lower for a width of 1^ miles. J. R. Grrimesey's well, 13 feet deep, at the 

 southwest corner of section 31, on this low tract outside the beach ridge, 

 encountered only very fine stratified sand, irregularly laminated and con- 

 taining numerous tubular limonitic concretions. Farther to the southwest 

 and west, a gently undulating surface of till, scarcely higher than the beach 

 of Lake Agassiz, stretches away several miles, beyond which the high- 

 land of the Coteau des Prairies is seen in the far distance. 



The Herman beach crosses township 129, range 49, iu a diagonal 

 course, entering it a half mile north of its southeast corner and running 

 northwest to the north side of sections 5 and 6. In section 23 and the 

 northeast part of section 22, its elevation is about 1,055 feet, but its dunes 

 rise 3 or 4 feet higher. At the middle of the north side of section 16 it is 

 a ridge of sand and fine gravel about 8 rods wide, rising 4 to 6 feet above 

 the land on each side. Its crest here and for a mile to the southeast 

 and northwest is 1,060 to 1,065 feet above the sea. Northeastward the 

 surface falls about 20 feet in the first mile. On the southwest side of this 

 distinct beach ridge, a smooth, slightly undulating tract 1^ to 2 miles wide, 

 extending through this township, consists of sand and fine clayey silt. Its 

 elevation varies from 1,055 to 1,080 feet, attaining the latter height in the 

 northwest part of the townshi}). This belt, with its continuation southeast- 

 ward, previously described, was doubtless covered by Lake Agassiz before 

 the erosion of its outlet to the level of the Herman beach; but its stratified 

 sand and silt appear to be modified drift deposited by streams from the 

 melting ice-sheet. The glacial recession here was from southwest to north- 

 east, and this was probably an avenue of drainage during a short time, as 

 was shown on page 150, till the continued retreat of the ice left a consider- 

 able expanse of water, the beginning of Lake Agassiz, between itself and 

 the shore. 



In the north part of secticms 5 and 6, township 129, range 49, and in 

 sections 31 and 32, township 130, range 49, this beach consists of two or 



