Report of the Survey of An- 

 cient Earthworks near 



OSBORN, O. 



BY PROF. J. E. WERREN, URBANA UNIVERSITY. 



The hill upon which the earthworks are situated, lies about one 

 mile east of Osborn, southeast of the two E.. E.. lines (the C. S. & C, 

 and the A. & Gr. W.); it is of an irregular oval shape, with the greatest 

 axis nearly N. and S., and about one mile in length. It rises from 

 the ancient bed of the Great Miami river, above whose waters it 

 probably projected as an island, 50 feet high (its present elevation 

 from the surrounding valley). The insular character is well attested 

 by the absence of sand and gravel (as well as drift) on the top, and by 

 the sedimentary formation in the outliers south and east, where clay, 

 gravel, and boulders are of common occurrence. 



The surface-layer of rocks belongs to the Clinton Limestone, 

 whose base, "or rather the summit of the underlying Cincinnati 

 Grroup, is a notable water bearer, or is shown by the fine line of 

 springs that issue from this horizon,"* noticeable especially when 

 ascending from the railroad. Other evidences of the Clinton Lime- 

 stone, especially this, that at many points the beds are extremely fria- 

 ble, are exhibited on this hill in the vicinity of the Springfield and 

 Dayton pike, where on"e quite remarable "sinkhole" may be observed; 

 it is without water, and to its lowest bottom studded with lofty trees. f 



In the absence of a name given to the hill collectively, the custom 

 is here followed of designating the localities on it, where aboriginal 

 remains are found, by the names of the respective owners, according 

 to which usage the northern extremity (marked A on the accompany- 

 ing plan) is known as Haddix Hill; south eastern extremity (marked 

 B) is owned by Mr. Mitman, and this portion is known as Mit- 

 man's Hill. (Haddix Hill lies nearly entirely in Clarke county; the 

 remainder of the hill, together with Mitman's Hill, is in Greene Co). 



*For further information see Part II, p. GG6 Ohio Geology. 

 fReport of the General Survey of Ohio Geology." 



