in the Sharon Coal of Northeastern Ohio. 63 



viously reported that it deserves brief mention. It was found 

 in the Marshall Mine of Mineral Ridge, Mahoning county, by 

 Mr. F. C. Goff, of Cleveland, who is extensively engaged in 

 mining and shipping coal, and it was removed from its bed by 

 his own hands. The thickness of the coal seam is three feet 

 and the bowlder lay two feet below the top. The seam was 

 in no wise disturbed in its structure by the presence of the 

 bowlder. The weight of the block in its present condition, 

 after the removal of a few small fragments, is 10 lbs. 10 oz. 

 It measures about eight inches in its longest dimension. The 

 coal is very closely welded to it over part of its surface and it 

 shows the usual slichensicled appearance. 



The noteworthy points in regard to this bowlder are the 

 following, viz : (1) It is the first so far as I know that has 

 been reported from this coal seam, viz : the Sharon Seam or 

 the lowest coal of the Conglomerate Coal Measures of Pennsyl- 

 vania and Ohio. (2) It is not a metamorphic sandstone or 

 quartzite, like those previously named, but is an excellent ex- 

 ample of vein quartz. (3) It has not been worn or shaped in. 

 any way by either water or glacial action, but is angular as if 

 freshly broken from the parent mass. 



]STo full and satisfactory explanation of this line of facts has 

 yet been advanced. The quartzite above named could perhaps 

 be accounted for without referring them in origin to the meta- 

 morphic rocks of the older regions of the continent. May not 

 an ordinary sandstone pebble or bowlder of the Coal Measures 

 have been converted into a quartzite by the solution of a por- 

 tion of its silica through the agency of the organic acids that 

 accompanied the formation of coal. But like the white quartz 

 pebbles of the great Sharon Conglomerate that underlies this 

 coal seam, the bowlder here described must be referred to the 

 ledges of the eastern or northern mountain borders of the 

 continent as it then existed. The pebbles of the conglomer- 

 ate never exceed a few ounces in weight and their rounded 

 forms and smooth surfaces bear witness to an immense amount 

 of abrasion before they reached their present resting places ; 

 but the bowlder in question, with its weight of 11 lbs. and its 

 sharp and unworn edges and with its anomalous location, cer- 

 tainly shows a very different history. 



Columbus, Ohio, May 13th, 1892. 



