THE NORCEOSS BEACHES IN MESHSTESOTA. 383 



is gradually diminished iu the successive lower shore-lines, each having 

 slightly less ascent than the preceding, to the McCauleyville beaches, 

 which rise 1 to 3 or 4 inches per mile. In all of these shore-lines the 

 rate of ascent is found to increase as one advances from south to north. 



BEACHES OF THE NORCROSS STAGES. 



FROM LAKE TRAVERSE TO NORCROSS AND MAPLE LAKE, MINNESOTA. 



(PLATES XXIII TO XXVI.) 



The Norcross shore-line of Lake Agassiz lies near the Herman shore 

 on the slope of eroded till which reaches about 4 miles east from the 

 northeast end of Lake Traverse. Thence eastward, from near the south- 

 line of section 35, township 127, range 47, Lake Agassiz was very shallow 

 during the Herman stage, and its fall of 20 feet, or, to speak with more 

 correctness, the rise of the land to this amount, between the times of 

 formation of the Herman and Norcross shore-lines, caused the lake margin 

 to fall back about 6 miles from its most southern portion. The Norcross 

 beach, having a height of 1,043 feet above the sea, is crossed by the Fargo 

 and Southern branch of the Chicago, Milwaukee and. St. Paul Railway at 

 a distance of nearly 1 mile north of Dumont. It is here a very slight 

 ridge of gravel and sand, rising only 2 or 3 feet above the uniform slope 

 of the very flat expanse of till. 



Within the next 3 miles to the east this beach becomes more con- 

 spicuous and has been excavated in several places to obtain sand for 

 masons' use. In section 12, Croke, it is a typical beach ridge about 25 

 rods wide, with a descent of 5 or 6 feet from its bi'oadly rounded crest 

 toward the north and 2 or 3 feet toward the south. At an excavation near 

 the line between sections 11 and 12 its crest has a height of 1,045 feet. 

 The depth of the beach sand and tine gravel, containing pebbles up to an 

 inch in diameter, is 5 feet, with till beneath. 



Thence the Norcross beach ridge, mostly 2 to 4 feet high, runs east 

 to Twelve Mile Creek, and beyond tui-us to the north and northeast. In 

 sections 32 and 33, Clifton, its height is 1,038 to 1,041 feet above the sea; 



