9. MADISON TOWNSHIP. F\ 255 



The Sand-rock ore bed probably runs along the whole 

 length of Conecocheague mountain in this township but has 

 nowhere been opened. To this bed must be referred the 

 reported discoveries of iron ore in the district. 



It is of little use to seek outcrops of these rocks on the 

 south slope of Tuscarora, for the immense mass of wreck- 

 age that has fallen from the Medina sandstone near the 

 summit has buried them beyond reach. 



BlstUne } s Mill section, ( V.) 



64'+Gray shale, 



Thin limestone, 



30' Gray shale, 



2' Shaly limestone, 



20' Shale, 



10' Limestone, (once quarried,) 



80' Shale, 



6 { Lime shale, 



( Limestone 



212 



255' Red shale, ^ 



5' Bridgeport sandstone, (?) . . > Bloomsburg red shale, 830' 



570' Red shale, J 



20 Ore sand rock, •, 



150'? Olive shale, ( 220' 



50' Iron sandstone, ) 



1262' 



This section deserves notice as it is the only place where 

 I have seen a sandstone, the equivalent of that at Bridge- 

 port or another resembling it, where its position could be 

 ascertained. 



The Onondaga shales, (V.) 



These shales occupy their usual position in the township, 

 that is on the top of the rocks composing the Clinton group. 

 They are, therefore, found in the middle of the synclines 

 such as Liberty valley and Shaeffer valley, the valley be- 

 tween Bower mountain and Chestnut ridge, &c, or near 

 the base of the Lower Helderberg limestone, and dipping 

 under them. They may be subdivided thus : 



Gray calcareous shales 



Bloomfield sandstone. 



