MISSISSIPPIAN-PENNSYLVANIAN UNCONFORMITY 109 



1,000 feet above sea, and is nearly 5 miles north of the above mill, 

 and when dip is taken into account the probability is very strong 

 that the phenomena seen at the two places belong to the same 

 horizon. 



A quite singular feature occurs in this shale at the fall. Near 

 its middle, and imbedded in it, lies a lenticular mass of conglomerate 

 a foot thick and probably weighing nearly a ton. It contains large 

 quartz pebbles, much pyrites of iron, and an impression of a cala- 

 mite. How was it transported to this place where only fine sedi- 

 ments were being deposited ? Where did it come from, and from 

 what rock formation was it detached? For the conglomerate beneath 

 must have been only a stratum of sand and gravel when it was 

 deposited. In central Ohio three other formations intervene 

 between the Cuyahoga and the base of the Pennsylvanian, the 

 lower one of which — the Black Hand — is known to be conglom- 

 eratic in part. Is this conglomerate block imbedded in this shale 

 a remnant of the Black Hand which once may have overlain the 

 Cuyahoga in northern Ohio, and was completely removed by 

 erosion before the close of the Mississippian ? These are ques- 

 tions to which only further study may reveal the answer. 



