92 THE GLACIAL LAKE AGASSIZ. 



drift, where the slope has been so hxtely uuderiuiiied that the shale forms 

 continuous cliffs from a few hundred feet to a quarter or half of a mile in 

 length. 



Fossils are infrequent, but Avould doubtless be detected in many places 

 by careful search. On the western slope of a hill, partially bared of ch-ift 

 and consisting of this shale, near the west line of section 33, township 139 

 north, range 58 west, 8 miles south of Valley City and about 1 J miles west 

 of the Sheyenue, I found Inoceramus sacjensis Owen, fragments of other 

 lamellibranchs, and Baculites ovatus Say. These were on nearly the aver- 

 age level of the surrounding country, at a height of about 175 feet above 

 the river, or 1,350 feet above the sea. 



In the vicinity of the southern bend of the Sheyenne are scanty 

 exposures of C!retaceous beds which contain lignite and may belong to 

 the Fort Benton formation. The lowest outcrop, situated just within the 

 highest shore-line of Lake Agassiz, is in the southeast quarter of section 

 82, township 135, range 54, about 20 rods west of Edward Bowden's 

 house. Here the east or right bank of the Sheyenne shows the following- 

 section, in descending order : Soil and gray clay, with slight intermixture 

 of gi-avel, 2 to 3 feet ; very coarse iron-rusty gravel, from 1 inch to 1 foot 

 thick, containing cobbles of limestone, granite, and a partly decayed gneiss, 

 of all sizes up to 6 and 12 inches in diameter; gray till, very compact, 1 to 

 IJ feet; fine gravel and sand, about 6 feet, containing in some portions 

 very plentiful flakes and fragments of lignite from an eighth of an inch to 

 2 or 3 inches long; and hard, dark-bluish Cretaceous shale, seen only 

 to the depth of a few feet and hidden below by the talus, containing near 

 its top a layer of lignite about 3 inches thick, at the height of 25 or 30 

 feet above the river, and approximately 1,060 feet above the sea. Springs 

 issue from the river baiik, a few rods farther southeast, at the top of this 

 shale. Mr. Bowden reports another outcrop of a thin seam of lignite, per- 

 haps belonging to the same layer, some 8 miles distant from this toward 

 the south-southwest, occurring in a ravine tributary to the Sheyenue, about 

 a mile west of its most southern bend. From the second to the first of 

 these localities the river falls 20 feet, and these outcrops of lignite diff'er 

 little in their elevation above the sea-level. 



