MLRPHREE'S VALLEY; ECONOMIC GEOLOGY. 57 



hard locks of the Clinton are bedded directly on the Trenton 

 limestone, no such bench has been formed. But if a large 

 bed of soft iron ore and its associated soft shales exist there, 

 they were readily eroded away back from the edge of the 

 Trenton, and this erosion would generally be in proportion 

 to the thickness or softness of this stratum. The debris, or 

 talus from above being spread over this bench, has buried 

 the edge of the abraded bed many feet deep, and it hence 

 makes no out-crop. Even the great exposure of this bed 

 near Village Springs (hereafter to be described), was not a 

 natural exposure ; but the result of cutting a drainage ditch 

 on the side of the public road. The water soon cut down 

 into the soft iron ore and exposed a sight which thirty years 

 ago was covered up by several feet of earthy matter. This 

 bench at the lower edge of the Clinton is generally broad 

 and well marked from the middle of section two to the corner 

 of section 16, in this Township, and several points farther 

 down. It again becomes prominent a mile above Village 

 Spring?, and continues to Village Creek. 



Near the middle of S. 10, T. 13, R. 1, E., the Trenton lime- 

 stone is flexed downwards beneath the level of the valley. 

 The flexure is short ; it regains its normal height again in 

 half a mile. Mill Creek cuts the remaining strata of the 

 mountain at this downward curve. This flexure crosses the 

 valley, as has been already noticed in the description of the 

 Carboniferous Limestone. It therefore opens a way of easy 

 access to the coal fields on either side, and through all the 

 sub- valleys, and makes this place peculiarly well adapted 

 for the manufacture of iron. All the needed raw material 

 could be concentrated here, more economically, than at any 

 other point in the valley. 



Through the remaining portion of this section the tipper 

 bed of iron ore crops out boldly, and occasionally the 2d and 

 3d beds are seen. This is also the case in N. W. ^ of sect. 15. 

 The s'urface indications show that ore is abundant, and that 

 probably all of the beds exist here. 



In section 16 several openings have been made on the 

 upper bed. It is more exposed and easier found than any 



