529 



[Clnypole. 



Geological Notes. By E. W. Claypole. 



(Bead before the American PJdlosophical Society, October 20th, 1SS2.) 



A. On an Error in Identifying Tloo Distinct Beds of Iron Ore in Beport Gc 

 of the Geological Survey of Bradford County. 



In Report G, Bradford and Tioga Counties, and on page 36, occurs the 

 following passage : 



"6. In Leroy township, about a mile and a half west of Leroy, in the 

 main road, near the house of J. Wilcox, we found a bed of iron ore which 

 appeared to be three or four feet thick, and of very good quality. See the 

 following partial analysis by Mr. McCreath : 



Iron 29.5 



Sulphur trace 



Phosphorus 204 



Insol. residue 49.27 



" 7. The sayne bed is exposed at Leroy village, in Gulf brook, where it 

 is nearly four feet thick and of good quality. A partial analysis uf this 

 ore by Mr. McCreath resulted as follows, though it can hardly be a fair 

 test, for the average percentage of iron must be greater : 



Iron 20.7 



Sulphur trace 



Phosphorus 185 



Lime 8.71 



Magnesia 1.3 



Insoluble residue 46.655 " 



In reference to this passage I was informed during a recent visit in Brad- 

 ford county by Mr. A. T. Lilley. of Leroy, that he considered it entirely 

 erroneous, and that these beds of ore so far from being one were separated 

 by a very considerable thickness of rock. The arguments which he ad- 

 duced appeared to me quite satisfactory, and we went out to examine the 

 ground. 



Antecedently, if the two samples of ore were fairly taken, the analyses 

 induce suspicion : they differ so largely from each other ; the quantify 

 of iron is half as large again in the former as it is in the latter. It seems 

 improbable that a bed of ore should vary so much in so short a distance. 



The plan of this part of the valley given in Fig. 1, page 535, will make 

 this line of argument intelligible. 



The lowest bed of iron ore occurs in the Gulf brook in connection with 



