158 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



feet above tide. In that vicinity he also fonnd a few small qnartz pebbles 

 in a surface loam capping the upland at about 840 feet above tide. 



In this connection it may be remarked that small stones apparently 

 derived from the drift, including greenstone, granite, and quartzite, are 

 scattered over the uplands in the vicinity of McConnelsville at various 

 altitudes up to 1,000 feet above tide. True has collected about a half 

 bushel of these erratics. As the glacial boundary seems to lie several 

 miles northwest of McConnelsville, it may be necessary to refer the dis- 

 tribution of these erratics to hinnan agency. The Indians were perhaps 

 responsible for their wide distribution outside the glacial boundary. The 

 small pebbles found in the surface loam, which are usually a half inch or 

 less in diameter, and are found at a depth of 1 to 4 feet from the surface 

 seem more likely than these larger pebbles to have been deposited by 

 natural agencies. The surface loam is apparently a water deposit, possibly 

 a phase of the loess, as indicated on a subsequent page. The loam and its 

 included pebbles point strongly to an interval of submergence which 

 antedated the Wisconsin gravel filling- in the valley of the Muskingum, but 

 which may be more recent than the change of drainage just discussed. _ The 

 subject is one requiring further investig'ation. 



STRIATED BLOCKS IN MUSKINGUM VALLEY NEAR m'cONNELSVILLE. 



True called the writer's attention to striated sandstone blocks found on 

 the slope of the east bluff of the Muskingum about 2 miles above McCon- 

 nelsville, at an altitude 780 to 800 feet above tide. They apparently were 

 derived from the ledges in the immediate vicinity. The striation consists 

 of a series of shallow grooves, which var}" a few degrees in trend and 

 seem less regular than glacial striae. Tlie writer has observed a grooving 

 more marked and regular than is here exhibited on a rock reef in the bed 

 of the Ohio River near Ravenswood, W. Va. As that locality is far outside 

 the glacial boundary, the grooving is apparently due to river ice. It seems 

 not improbable, therefore, that the grooving displayed by these blocks is 

 referable to the transportation of stones by river ice when the stream was 

 flowing at an altitude as high as these ledges. 



EXTENT OF THE OLD MUSKINGUM DRAINAGE BASIN. 



The old Muskingum drainage basin extended up the Tuscarawas 

 nearl}^ to the mouth of One Leg Creek, a distance of 75 miles above the 



