18S1.] ^51 [Stevenson. 



rock sliown at the base of the Knox wall is some Hamilton shale. But at 

 Mr. Boatwright's place on Stony creek, the Lower Carboniferous, Hamil- 

 ton, Oriskany, Lower Helclerberg and Clinton were all recognized between 

 the Conglomerate and the Knox group. These seem to come in reversed 

 order as already explained. 



The exposure on Mr. Boatwright's property is good. Two beds of the 

 Clinton ore were seen there, which represent the upper and middle beds of 

 the Poor Valley ridge. The upper bed is silicious and no special investi- 

 gation of it was made. The other was exposed to a thickness of 3 feet for 

 examination and it is said to be 6 feet thick in an excavation now filled up. 

 But this thickness is doubtless an exaggeration, and the excavation may 

 have followed the dip, which is abrupt. Leptoccelia hemispherica was 

 recognized in this bed. The ore analyzed by Mr. McCreath yielded : 



Metallic iron 43.650 



Sulphur 0.008 



Phosphorus 0. 101 



Insoluble residue 31. 480 



The Lower Helderberg brown hematite is exposed at several localities 

 here on both sides of Stony Creek valley. Samples of the ore analyzed by 

 Mr. McCreath showed : 



Metallic iron 41.375 



Sulphur 0.060 



Phosphorus 0.890 



Insouble residue 22. 200 



But it is clear that the samples from this bed are not altogether fair, as 

 the yield in a forge seems to have been greater than the amount of iron 

 shown by analysis. This ore was digged to some extent for use at the forge 

 on Moccasin creek near Estillville ; but the diggings were abandoned 

 many years ago and the samples were taken from loose pieces which had 

 been' weathering for probably 20 years. The limestone of the Lower Hel- 

 derberg is very fossiliferous and its species ally it closely to the Delthj ris 

 Shaly Limestone of the New York group. The Oriskany sandstone is well 

 shown and contains Streptorhynchus Mpparionyx. 



There is little of interest between the Hunter Valley fault and Clinch 

 river. In descending Stock creek, one finds himself constantly in the 

 shales and limestones of the Knox group and the dip is not rapid until near 

 the river. The creek flows through a great tunnel in magnesian limestone. 

 The limestone is so magnesian that the inhabitants of the neighborhood 

 use it as a purgative instead of epsom salts. Midway in the cliff, which 

 overhangs the mouth of the tunnel, is the entrance to a great cave which 

 reaches to within 65 feet of the summit of the hill. The tunnel is 500 feet 

 long, 25 feet high and 35 feet wide. The surveyed line of the Bristol 

 Narrow Guage Railroad passes through it. 



The elevated area known as Rye cove is but a little way east from Stock 

 creek. There the dip of the limestones is gentle and the projecting rocks 



PIIOC. AMER. PHILOS. SOC. XIX. 108. 2f. PRINTED FEBRUARY 25, 1881. 



