170 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



at Sugar Grove, or about one-fourth of a mile; it continues narrow for the 

 next 5 miles, and below it is ii-regular and varies in width from one-fourth 

 mile u]) to nearly a mile. The level of the rock floor in the narrow part 

 below Sugar Grove, as shown by gas borings, is about the same as at that 

 village, 650 feet, but farther down it appears to descend with the present 

 stream. From the features just noted it seems probable that the old divide 

 stood within a few miles southeast of Sugar Grove, but its precise position 

 may be difficult to determine. 



Beginning a short distance below Sugar Grove there are shelves along 

 the borders of the valley at a height of 50 to 75 feet above the stream, or 

 about 800 feet above tide; these seem to be remnants of an old gradation 

 plain. By means of these rock shelves it may be possible to determine the 

 condition of the old divide, but this has not as yet been done. It is still to 

 be determined whether the portion of the Hocking Valley below this divide 

 belonged to a single or to two or more distinct old drainage systems. 



Upon turning to the tributaries of this headwater portion of Hocking 

 River we find important changes. Clear Creek now drains a district east- 

 ward into the Hocking that was in large part drained westward into the Scioto 

 Basin. The old divide between the westward-flowing stream and a much 

 smaller stream flowing eastward into the Hocking- is found about 4 miles 

 from the mouth of the creek. The creek here passes through a gorge only 

 100 to 150 yards in width, or but a small fraction of its width near its 

 present headwater portion. Above this gorge the tributaries of the creek 

 point westward, while in the poi'tion below they point eastward. The 

 bluffs at this gorge rise abruptly more than 1 00 feet, and it is probable that 

 the pass or col stood nearly as hi^h as this abrupt part. This old divide is 

 very near the glacial boundarj^, but a terrace of glacial gravel appears 

 farther down the valley, at an altitude about 100 feet above the stream bed. 

 This gravel is apparently of Illinoian age; this being the case, the stream 

 was thrown across this divide as early as that ice invasion. 



Changes of di-ainage on Rush Creek, the largest eastern tributary of 

 this headwater portion of the Hocking, have been noted both by Tight 

 and the writer. An abandoned valley, forming the old line of discharge 

 from Bremen to Lancaster, was examined by the writer in 1890, and the 

 caiise for abandonment referred to great accumulations of drift immedi- 

 ately below Bremen. The position of the old divide crossed by the stream 



