Feb., 1907.] The Columbus Esker. 71 



were troughs of non-conformable cross bedding. The latter 

 were probably the work of small rivulets. Frequent excava- 

 tions for other buildings adjacent to High Street often show this 

 deposit of water-assorted glacial material. This sometimes is of 

 a much coarser nature, large cobbles and bowlderets often form- 

 ing the greater amount of the deposit. In South Colimibus on 

 the bluffs of the Scioto just off High Street fine examples of 

 stratified drift occur. These are located well up in the drift. 



In this part of the city there is also a gentle swelling of the 

 drift to form a ridge-like formation, which reaches its culmina- 

 tion in Baker's Hill, 819 feet above tide. South of this other 

 more or less distinct elevations occur until Spangler's Hill, 817 

 feet, is reached. Still further south a few indistinct knolls or 

 short ridges occur. About opposite Duvall, in Pickaway County, 

 a low ill-defined sand ridge gradually develops, which continues 

 (at places almost wanting) for about a mile until the north end 

 of the Circleville Esker is reached. This stands out some 40 or 

 50 feet above the surrounding country. 



Are these level stratified deposits of the various parts of Co- 

 lumbus sand plain or alluvial fan deposits of the above glacial 

 stream? Or are the knolls, short ridges and gravel hills, which 

 lie between this Columbus Esker and the Circleville Esker, in- 

 terrupted deposits of this glacial stream? Or is the Columbus 

 Esker simply one of those short gravel ridges which cannot be 

 definitely connected with a delta deposit or another esker system f' 

 Further field work and study alone can solve this, if a solution is 

 possible, and this the writer hopes to be able to accomplish. 



Practically ever since the abandonment of the ice-berg theory 

 and the introduction of the glacial hypothesis for the origin of 

 the till. Geologists have attributed eskers to fluvio-glacial action. 

 Some have held that they were accumulated in supra-glacial 

 streams. Some have argued this method together with en- 

 glacial stream deposition. More, however, have attributed them 

 to sub-glacial streams, while still others have favored all three 

 methods in varying degrees. Opposed to the supra-glacial and 

 en-glacial origin Chamberlin and Salisbury say that: " (1) So far 

 as known, the surfaces of ice-sheets are free from drift (apart 

 from wind-blown dust) except for a fraction (and generally a 

 small one) of a mile from their edges; and (2) superficial streams 

 are, in general, much too swift to allow of the accumulation of 

 drift in their channels." (^*') 



Geikie also found strong arguments against the superficial 

 stream deposit and concluded by saying: "The tendency of sup- 

 erficial water-flow would be rather to distribute morainic mater- 

 ial (material upon the ice) in irregular sheets over the surface 



JO. Geology, Vol. III. p. 376. 1906. 



