FRANKLIN COtJNTT. 60e5 



Huron shale, occurs on the same side of the river, and but a little ways 

 back, in various exposures, for eight miles to the southward. The actual 

 thickness of the sections found here is about seventy-five feet. 



A section found i in this neighborhood, at Corbin's Mills and on the 

 adjacent land of Joseph Ferris, can be taken as a fair representative of 

 the series here. It is shown in the annexed wood cut. Beginning at the 

 water's edge, a heavy course of cutting stone is first seen. Its thickness 

 sometimes rises to two and one-half feet. This is overlain by eight feet 

 of buff colored magnesian limestone, which lies in quite heavy but rather 

 uneven beds. These courses have a maximum thickness of three and 

 one-half feet, and an average thickness of two and one-half feet. They 

 are raised in blocks sufficiently large to make them valuable as a cutting 

 stone. They are easily wrought, especially when first quarried, and on 

 this account have acquired the local names of "freestone" and "sand- 

 stone." 



These courses are followed by five feet of thinner bedded rock, the 

 thickness of the layers ranging between four and eight inches. Two of 

 these layers, one near the bottom and the other near the top of the sec- 

 tion, hold flint concretions. These occur in irregular nodules, chalk 

 white on the outside, and often of the same color throughout their sub- 

 stance. They are very rich in the fossils of the formation, and these are 

 here found in a remarkable state of preservation. Univalve shells of the 

 genera Murchisonia, Loxonema, Pleurotomaria are especially abundant and 

 perfect. Very fine casts of the brachiopod Meriitdla nasuta, Conrad, occur 

 here also. Several of the type fossils of the formation were described 

 from specimens found in the flint of this geological horizon. 



The flinty layers in the section are overlain by nineteen feet of light 

 colored beds, commonly called " white limestone." These beds are crowded 

 with fossils, of which brachiopod shells are the most numerous. The beds 

 are thin, seldom exceeding six inches, and not very even. They furnish 

 at the best " building stone " as distinguished from " cutting stone," but 

 the most valuable application that can be made of them is in lime burn- 

 ing. They yield a very strong and very white lime. 



The nineteen feet shown in the quarry above the mill, together with 

 the lower portion of th'e next division marked in the cut, constitute the 

 Delhi beds of Prof. Winchell. *This next division, eleven feet in thick- 

 ness, is not homogeneouSj as has been already intimated. It is not clearly 

 shown at this point, but the uppermost five or six feet are made up of 

 shaly layers, not adapted either for building stone or lime burning. Their 

 upper boundary is made distinct by a remarkable layer called the bone 

 bed, which will be described in detail on a subsequent page. 



* See Keport on Delaware county. Vol. II Geology, page 297. 



