MURPHREE'S VALLEY; ECONOMIC GEOLOGY. 103 



covered, and the only valuable. portion of the 5th horizon, or 

 Sub-Carboniferous Limonite. The two lest deposits of this 

 ore, which this valley contains, are here brought into such: 

 close proximity, as practically to make them one. The nor- 

 mal position of this Sub-Carboniferous ore is about 1,500 feet 

 above the Lower Limonite, yet it is here brought to the 

 same level on the S. W. end and 150 feet below it at the N. 

 E. end of the exposure. 



Another fact may be noticed, opposite the N. E. end of 

 this limonite, a gap exists in the vertical wall, or edge of 

 the valley, through which, and on the same level, can be 

 reached several beds of coal, less than 1,000 feet distant 

 from the iron. Thus making here a concentration of 

 economic values, which probably cannot be paralleled. 

 Should this coal prove suitable for the manufacture of iron r 

 its apparent abundance and proximity to the ore, will give 

 advantages for utilizing both in the vicinity, and greatly en- 

 hance their relative values. 



In this great deposit of brown ore, there is no indication 

 of any rock. It is a great mass of ochery, and ferruginous 

 clay, with chunks, masses and particles of imbedded ore in- 

 terspersed through it, apparently without regularity. In 

 most places on the surface it is thickly strewn. If we should 

 judge of the contents of the bed by the abundance of the 

 surface specimens alone we should probably make an over- 

 estimate, for the quantity on the surface is mainly due to 

 denudation, which has carried off the surrounding clay, and 

 left the iron ore. In some places the ore is in much greater 

 quantities on the surface than in others; this may only be 

 due in part to denudation. Probably the ore lies very irreg- 

 ularly scattered through the bed, in bunches and pockets r 

 as is always the'case in limonite deposits. The proportion 

 therefore of clay to the ore, cannot as yet be safely approxi- 

 mated. In a few places where it has been dug into for a 

 few feet, the proportion was about 3 or 4 of ore to 1 of clay r 

 but these were places carefully selected, to show as much 

 ore as possible, and none of them had gone deep enough to 



