328 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



bluffs, observations made by Orton, and later ones by Cliamberlin, give the 

 strise a bearing S. 8°-12° E. 



About 4 miles east-northeast of Urbana, in a quarry south of Long's 

 station, there are exposures of strise which bear about E. 10° N. The east- 

 ward movement is clearly indicated on the rock surface, whose prominences 

 show plainly that their west side is the stoss side. This bearing is nearly 

 at a right angle to a moraine in which this quarry is situated, whose trend 

 in that vicinity is from slightly west of north to east of south (see Pis. 

 II and XI). 



INNER BORDER DISTRICT. 



The district which lies between the Hartwell moraine and the next later 

 one (the outer moraine of the late Wisconsin series) comprises only a few 

 counties in southwestern Ohio and southeastern Indiana. Its extent may 

 be seen by reference to the map of the Maumee-Miami lobe (PI. XI). 



TOPOGKAPHY. 



The features are somewhat diversified. The Ohio portion is hill)", 

 except near the border of Indiana in Preble and Butler counties. The hills 

 have rock within a few feet of the surface; the main drainage lines remain 

 essentially the same as in preglacial times. The valleys of this region, 

 especially those of streams like Fourmile, Sevenmile, and Indian creeks, are 

 characterized by a peculiar filling with till. The till is several times as deep 

 as on the uplands, and is level topped or nearly so, giving the appearance 

 of a terrace when viewed from the uplands. In the lower portions of these 

 streams the till has been channeled to a depth of 75 to 100 feet, and forms 

 an inner and lower bluff. Above these lower bluffs of till stand the rocky 

 upland tracts 200 to 300 feet or more higher than the streams. The plane 

 surface which the till presents in these valleys is perhaps no more remarka- 

 ble than that of upland plains. Had the amount of drift been sufficient to 

 have nearly filled the valleys the plane surface would scarcely suggest a 

 terrace. 



Two valleys in this inner border district. Mill Creek Valley and a val- 

 ley leading from the Little Miami at Kings Mills to the Great Miami at 

 Middletown, resemble the valleys above mentioned in having level-topped 

 plains in them, but a view of these plains from bordering uplands does not 

 suggest a terrace, since the small streams now occupying them have scarcely 



