78 GEOLOGICAL RECONNOISSANCE. 



calcareous bands locally interstratified amongst the layers, exposed in the 

 north-cast bank of that stream. 



At the crossing of a branch, five miles south-east of Burrowsville, the 

 subcarboniferous limestones alternate with sandstone and grey fossilifer- 

 ous shale, underlaid by some 50 feet of flaggy sandstone, resting on the 

 dark shales which crop out about half a mile down the branch, to the left 

 of the road. The gray fossiliferous shale, to the right of the road, lies 

 about 85 feet above the base of the flaggy sandstones ; above this are 

 alternations of sandstone and grey limestones, while on the slope of the 

 adjacent hillsides, gravel of black flinty chert is everywhere strewed. 



Four, to four and a half miles south-east of Burrowsville, the sandstone 

 overlying the black shale has a disposition to split into rectangular, pris- 

 matic blocks. 



At Burrowsville, the present county-seat of Searcy county, there is a 

 buff, flaggy sandstone, which is quite fossiliferous; some of the layers are 

 charged with casts of Producta. The rock has been quarried to a limited 

 extent, in the immediate vicinity of Burrowsville, and has been used for 

 foundations and underpinning to buildings, and in the construction of 

 chimneys. 



North-west of Burrowsville, the black shale was not seen ; the descent 

 from the productal flags leads immediately on to chert and light-grey 

 subcarboniferous limestone ; unless, therefore, the black shale is entirely 

 concealed from view, the productal flags of Burrowsville must underlie 

 the black shale, so frequently exposed in Wiley's cove, and between that 

 and Burrowsville. A black slate is said to be exposed in a ridge west of 

 Lebanon, where there is an extensive lick ; this locality, I have not yet 

 had an opportunity of examining. 



In the vicinity of Lebanon, on the north bank of Bear creek, are 

 perpendicular cliffs of cherty, subcarboniferous limestone ; one bed of 

 which is nearly white, and of a texture passing from granular into sub- 

 crystalline, with large Spirifers, allied to, but probably distinct from 

 Spirifer striatus, which occurs in the same position on the Rapids of the 

 Mississippi, above the mouth of the Des Moines, under the Archimedes 

 beds, and above the Keokuk cherty limestone containing Orthis crenis- 

 tria, which is superimposed on the encrinital beds of Burlington. 210 

 feet of these cherty members of the subcarboniferous limestone is exposed 

 on Bear creek; above the principal escarpment there is a slope of 100 feet 

 more, where only loose pieces of chert are visible amongst the vegetation. 



At the next crossing of Bear creek, vertical walls of cherty limestone 

 are again seen, where they dip 4 deg. to 5 deg. south-west. Here the 



