MURPHREE'S VALLEY ; GEOLOGICAL FORMATIONS. 21 



across the valley in a south-east direction, and produced a 

 like depression in every one of the exposed formations. This 

 flexing up and down of the strata, in a direction transverse 

 to the normal dip, has been seen at many places, but gen- 

 erally is more clearly shown in the older rocks. 



From this point S. 3, T. 13, R. 1, east the limestone 

 continues prominent down the valley to the Blackburn Fork ; 

 it again* sinks, and apparently a fault crosses the valley op- 

 posite this place ; the older rocks, however, give the best evi- 

 dence of it. After rising again to the surface, and being oc- 

 casionally considerably above it, it sinks beneath the base- 

 of the valley opposite Village Springs. 



On the south east side of the valley the Sub-Carboniferous 

 limestone can only be seen at two points. The first is a short 

 distance outside of the valley, in sections 26 and 35, T. 14.. 

 R. 1, west, where a fault, probably the minor fault below 

 described, leaves the valley and runs southward into Sprad- 

 ling's Cove. This limestone is prominently brought up by- 

 it, immediately outside of the vertical wall of the valley r 

 and from thence on to the middle of Spradling's Cove in 

 section 11, T. 15, R. 1, west. The other point is in sec. 27, 

 T. 13, R. 1, east, where a stream has cut a deep chasm 

 through the vertical wall ; the top ot this limestone is exposed, 

 in the bed of the stream, a short distance inside the base of 

 the vertical wall. 



The Carboniferous limestone, so largely exposed on the 

 north-western side of this valley, is the most valuable of our 

 lime formations. It is generally purer than the older un- 

 crystalized lime rocks. It is therefore preferred for the 

 manufacture of lime, and for flux in the manufacture of iron. 

 The principal supply for the use of the furnaces at Birming- 

 ham and the adjacent region, is at present obtained from 

 this formation at Blount Springs and at Truss ville, and also 

 from quarries a few miles west of Village Springs, where it 

 exists in great abundance, and of excellent quality. But 

 many other exposures of it, believed to be equal to those in 

 quantity and quality, are presented in this valley. In quality 

 it varies much from place to place all lime rocks do so and 



