272 THE. ILLINOIS GLACIAL LOBE. 



were also noted at Funk's Grove and at points below. The gravel was 

 apparently transported to the junction of this fork with a more western 

 tributary. In each of these valleys the gravel is of medium coarseness 

 and carries a moderate admixture of sand. The presence of the sand is 

 thought to indicate that the current was not vigorous, though it may have 

 been somewhat stronger than that of the present stream, for the latter finds 

 it difficult to transport the coarser portions of the material even at flood 

 stages. As these valleys are narrow, averaging scarcely more than one- 

 fourth mile and seldom reaching one-half mile in width, the glacial streams 

 which occupied them can not have had very great volume. The depression 

 on the outer border of the moraine does not seem to fit in naturally as a 

 part of the drainage which preceded the formation of the morainic system. 

 As yet, no satisfactory explanation of its mode of formation has been found. 

 Possibly it Avas formed in connection with the ice invasion, either by the 

 ice or by waters issuing from it. It bears some resemblance to "The 

 Fosse" on Nantucket Island described recently by Curtis and Woodworth 

 in the Journal of Greology, though it has not a sand plain or overwash 

 apron on its south border. 1 



On the branch of Sugar Creek which leads through the west part of 

 Bloomington there is a belt of gravel 60 to 120 rods in width, which 

 extends up the valley at least to the Bloomington waterworks in sec. 32, 

 Normal Township, just outside the inner large ridge of the Bloomington 

 morainic system. At its head it is merged with the flood plain of the creek, 

 but from Bloomington southward it stands a few feet above the flood plain. 

 The depth of gravel at the waterworks is about 30 feet, and it appears to 

 maintain this depth for some distance below Bloomington. There is usually 

 a yellow-brown silt 4 to 6 feet in depth capping the gravel. The gravel 

 contains a large amount of fine material, so that sand is screened from it 

 for plasterers' use. Large pebbles are rare, though it contains a few 5 or 6 

 inches in diameter. This branch of Sugar Creek reaches the outer border 

 of the Bloomington morainic system about 5 miles below the waterworks. 

 The gravel here spreads westward beyond the limits of the valley, covering 

 the lower portions of the plain between this branch of Sugar Creek and 

 one that leaves the moraine 4 miles <to the west, Low till swells rise above 



'Nantucket a morainal island: By G. C. Curtis and J. B. Woodworth, Jour. Geol., Vol. VII, 

 1899, pp. 226-236, PI. I, Figs. 1-5. 



