460 THE GLACIAL LAKE AGASSIZ. 



sliore is known to be indicated by erosion or by grii\el and sand deposits, 

 but more commonly it is not clearly traceable. It thence n;ns slightly 

 west of north to the international boundary, but has not been examined 

 along' that distance of nearly 50 miles. 



Lying about 10 feet below the preceding, the lower Ojata shore crosses 

 the Red River near Caledonia and the mouths of the Goose and ]\Iarsh 

 rivers, being there about 865 feet above the sea. From 5 to 12 miles north- 

 ward in Minnesota it runs along the west margin of the great marsh of the 

 Sand Hill River. Onward through this State it must lie mostly 1 to 2 miles 

 west of the upper Ojata beach, though generally it is indistinct and its 

 covu'se has been nowhere exactly noted. 



Portions of the Ojata beaches in North Dakota have come under my 

 observation from the vicinity of Reynolds and Thompson north-northwest- 

 ward across Grand Forks and Walsh counties. The upper shore is not 

 clearl}^ exhibited where it is crossed by the Great Noi'thern Railway, about 

 2 miles south of Tiiompson, but the lower shore is marked by a beach ridge 

 of gravel and sand, which is crossed 1 mile north of this station. The crest 

 is about 8G8 feet above the sea, with descent of G to 8 feet from it toward 

 the northeast and 2 or 3 feet southwestward. 



On the south line of section 36, Oakville, and of section 31, Brenna, 7 

 to 8 miles northwest from Thompson and 5 miles south of Ojata,^ the 

 heights of the crests of the Avell-developed upper and lower Ojata beaches 

 are respectively about 880 feet and 872 to 875 feet. One to 2 miles south- 

 eastward, however, these shore-lines have neither beach deposits nor any 

 notable erosion on the -smooth, gently sloping surface of till. 



The Great Northern Railway between Emerado and Ojata intersects 

 the crest of the upper Ojata shore-line a quarter of a mile west of the 

 northeast corner of section 8, Oakville, about 3 miles west of Ojata. It 

 consists of a somewhat prominent escarpment of till, which falls tVom west 

 to east at first 7 or 8 feet within 15 or 20 rods, and as mucli more within 

 the next third of a mile, its base being 862 to 865 feet above the sea, whence 



1 Meaning forhs in the Dakota or Sioux language, and referring, like Gran<l Forks, to the junc- 

 tion of the Red and Red Lake rivers (A. W. Willianison. m Thirteenth Annual Report, Geol. and 

 Nat. Hist. Survey of Minnesota, for 1884, p. 110). 



