CAMPBELL EMBANKMENT AND BEAOHES. 421 



extensive embankment was by transportation of its material along the shore 

 that is m;u-ke(l l)y this lieach ridge, and b}' building it thence ont into the 

 lake in this long hook bent to the west, which grew graduall}' in length 

 and in height until it rose to the lake level, its growth afterward being by 

 additions to its width. From its eastern verge a slope of the same gravel 

 and sand falls 30 to 40 feet in a third or half of a mile, to a south-to-north 

 belt of dimes and sand ridges, 10 to 15 feet high, which appears to repre- 

 sent the McCauleyville beaches. West of this embankment a basin 15 to 

 40 feet below it, mostly consisting of fertile wheat land, well drained by the 

 Tongue River, extends G miles from south to north, with a maximum width 

 of about 3 miles, lying between the embankment and the southeastern bor- 

 der of the Pembina delta, which was the lake shore during the Norcross 

 and Tintah stages. The prevailing course of the coastal currents of Lake 



--~o"=^^----.'7'M^ t--^..- '»-r--„v~--„ T ^ ' ^ b--^ ' ■,■.---.-■■■■-.!- .-o- ;T =ii^ 



Fig. 19. — Section across the Campbell embankment in sections 20 and 21, township IGl, range 55. Horizontal scale, 

 one-tbird of a mile to an inch; vertical scale, 100 feet to an inch. 



Agassiz, and of the transportation of its beach materird here and elsewhere, 

 on both its western and eastern sides, was from north to south, as now ou 

 Lake Michigan, due then and now to the prevailing directions of the winds, 

 and especially of gales in severe storms, when the broader and higher 

 portions of the beaches were chiefly amassed. 



At Walhalla and northwestward the Campbell shore-lines run along 

 the base of the escarpment of the Pembina delta, -where its steep descent 

 is succeeded by a more gentle slope. Rev. John Scott's house, a half mile 

 west of Walhalla, and the houses of H. A. Mayo and John Harvey, respec- 

 tively about a half mile and "2 miles farther northwest, are on the principal 

 lower Campbell shore, which in part is a well-developed beach ridge, with 

 ci'est 1,030 to 1,035 feet above the sea, but mostly is a terrace eroded in 

 the delta deposit, falling from 1,040 to 1,020 feet, approximatel)'. In the 



