15S [lawman — Glacial Modification of Dramage 



The throe very small streams that comprise the far- 

 thest headwaters of East Sixmile rise at an elevation of 

 about 1770 feet and, after an independent How of a quar- 

 ter of a mile or so, coalesce to form the more easterly of 

 the two larger branches that join to form the main Six- 

 mile Creek. From this point of junction of the three 

 headwater streams, East Sixmile pursues a southward 

 course, and its volume is further augmented by six other 

 tributary streams before the point of its union with West 

 Sixmile is reached. Just above this point of union the 

 stream flows through a gorge from 50 to 75 feet in depth 

 (G, fig. 2). The merging of East and West Sixmile 

 develops a relatively large stream, and this increase in 

 volume has resulted in the deepening of the gorge below 

 the point of the confluence already alluded to. From the 

 lower end of this gorge to within half a mile of Slater- 

 ville Springs the main Sixmile Creek takes a meandering 

 course through the bottom of a drift-filled valley along 

 the eastern side of which a gorge wall obscured by glacial 

 drift can occasionally be detected (T, fig. 2). In this 

 lower course the creek receives additions from the com- 

 bined Moss and Spring Creeks (E, K, fig. 2) and from 

 several other less important tributaries. 



About one-half mile west of Slaterville Springs a 

 small creek, here termed Gravel Creek (Q, fig. 2), joins 

 Sixmile, and pushes its headwaters up a moraine-filled 

 valley for a distance of three miles. This creek is now 

 in the drift-filled valley which, it is suggested, was, prior 

 to the glacial occupation, occupied by West Sixmile, but 

 was subsequently abandoned by that stream in conse- 

 quence of the deposition of the morainic mass (I, fig. 3) 

 between Rowe and Gilbert Hills (L, U, fig. 2). This 

 mass of moraine, termed here the Moss Creek Moraine, 

 and evidently a stadial moraine, apparently diverted 

 West Sixmile Creek across what may have been the 

 eastern rock wall of the West Sixmile valley and forced 

 it to cut the gorge through which it is now flowing. 



Glacial Modifications of the Topography. 



Only the highest elevations in the Upper Sixmile drain- 

 age area exhibit outcrops of bed rock, and these are both 

 infrequent and of small exposure. The remainder of 

 the area is mantled deeply with a thick drift deposit 



