the eroded Mississippian surface, sometimes upon the Maxville 

 limestone, or where that formation has been entirely removed, upon 

 the Logan shales. In places it is so intimately associated with the 

 Maxville limestone that it was formerly considered the upper part 

 of that formation; 1 but Morse in his detailed work on the Maxville 

 of Muskingum and Perry counties proves the horizon to be of Penn- 

 sylvanian age. 2 In southern Ohio at most localities, the ore appears 

 as a distinct horizon above the Mississippian-Pennsylvanian un- 

 conformity. 



In lithologic character the Harrison ore varies greatly from place 

 to place. It is generally coarse in texture, and is composed of a 

 conglomeratic mass of quartz pebbles, cherty material, and fragments 

 of sandstone which have been cemented together by iron oxides. 

 The cherty material seems to have been derived from the Maxville 

 limestone which had been weathered into small fragments during 

 the long period of erosion after the withdrawal of the Mississippian 

 sea. These products of decomposition were later reworked by the 

 incoming Pennsylvanian sea and were cemented by iron compounds. 

 Many of the rounded quartz pebbles resemble those of the Sharon 

 conglomerate which lies only a few feet above the ore or sometimes 

 rests directly upon it. The member is generally poor in fossils, and 

 where these occur, they appear mostly as internal casts and present 

 an extremely dwarfed aspect. 



The Harrison ore is too poor in iron content to be of economic 

 importance; its high percentage of silica and patchy outcrop also ren- 

 der it undesirable for commercial use. At present it is nowhere used 

 commercially, although in the early history of the State it was utilized 

 to a very limited extent in the charcoal furnaces of Scioto, Jackson, 

 and Muskingum counties. 



Description of Geological Sections and Collecting Localities 

 Scioto County. In Scioto County the ore is found only in Harri- 

 son Township, from which locality it was named by Stout in 1916. 3 

 The following geologic section, measured on Munn Hill, in Section 32, 

 shows the variable character of the deposit: 4 



Pottsville formation Ft. In. 



Shaly sandstone 20 



Coal, bony, Anthony 6 



Clay, flint, Sciotoville 3 6 



Shales and parts covered 38 



Conglomerate zone, flint, boulders, shale, ferruginous 



clay, Harrison homon . . 2 



Logan formation 



Jackson County. The Harrison ore outcrops in the stream bed 

 and valley walls of a small tributary which the Little Scioto River 



iQrton, Edward, Geol. Surv. Ohio, Vol. V, pp. 373-379, 1884. 

 sMorse, W. C., Geol. Surv. Ohio, Fourth Ser., Bull. 13, pp. 35-5 

 "Stout, W., Geol. Surv. Ohio, Fourth Ser., Bull. 20, p. 481, 1916 

 'Idem, p. 482. 



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