338 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



pebbles are to a large extent, dismtegrated. The calcareous material witli 

 which the waters that percolate this terrace are charged forms a slight 

 cementation of portions of the terrace from whicli the water is removed by 

 evaporation. 



The terraces of the Little Miami were probably btiilt up in part by 

 glacial streams from the vicinity of Kings Mills, where the ice sheet came 

 down to the borders of the valle}^, as well as from the point where the 

 moraine crosses the stream near the moi.ith of Csesars Creek, and from the 

 Scioto lobe along Todds Fork. It is not known whether glacial terraces 

 lead in from the East Fork, that stream not having been examined. On 

 account of these numerous lines of discharge, the lower portion of the Little 

 Miami Valley and the portion of the Ohio Valley immediately below the 

 mouth of the Little Miami were greatly filled by gravel, there being in the 

 city of Cincinnati a filling from a level somewhat below the present stream 

 to a level about 110 feet above it, the greater part of which is gravel with 

 but a slight admixture of sand and earthy material. 



As above noted, statements that the rock floor of the Ohio Valley at 

 Cincinnati stands 120 to 200 feet below the present bed^ are probably due 

 to confounding the terrace with the river bed, which would make a diff"er- 

 ence of about 110 feet. After careful inquiry the writer could learn of no 

 wells within the cit}^ limits which show the rock floor to be lower than 75 

 feet below low-water mark. Records of wells were obtained at various 

 parts of the city showing the distance to rock in the midst of the valley as 

 well as on its borders, as follows: 



East End Gas Works, near north bluff, penetrated 130 to 135 feet of 

 drift, striking rock at 70 to 75 feet below low-water mai'k. 



West End Gas Works, in midst of valley, penetrated 118 feet of drift, 

 striking rock at 58 feet below low-water mark. 



Storr's distillery (formerly Gaff's), west of Mill Creek, near mouth, 

 has one well that struck rock at 40 feet below low-water mark, while 

 thirteen others failed to strike rock, though terminating at levels 40 to 50 

 feet below low-water mark. 



The pier on the Ohio side of the suspension bridge rests on rock at 

 about 40 feet below low-water mark, while the middle pier of the Chesa- 

 23eake and Ohio Railwa)'' bridge was reported by Joseph F. James to rest 



iSee Geology of Ohio, Vol. I, 1873, p. 433; also Bull. U. S. Geol. Survej' No. 58, 1890, pp. 79-80. 



