CLAEK COUNTY. 13 



clay shale with, thin plates and nodules of limestone. These shaly 

 layers afford many Hue fossils in a very perfect state of preservation, 

 though they are neither as numerous or as well preserved here as at 

 the outcrops of this limestone in Edgar county. The most character- 

 istic fossils of this formation are Meekella striato-costata, Pleurotomaria 

 turbinifonnis, and Platyceras Nebrascm&is, associated with Athyris subti- 

 lita, Spirifer cameratus, S. lineatus, Spiriferina KentucTcensis, Orthis 

 carbonaria, Platyostoma Peoriense, Terebratula bovidens, Chonttes Ver- 

 neuilianus, numerous corals like Heliophyllum, aud large joints of 

 Grin> idea. Possibly the apparent thiuniug out of this limestoue to the 

 northward in this county may be due to surface erosion, as we nowhere 

 saw the overlaying sandstone in situ, and Prof. Bradley gives the 

 thickness of this bed in Edgar county as about 25 feet, which does not 

 indicate a very decided diminution of its thickness in a north-east- 

 ward ly direction. 



Below this limestone, in the vicinity of Martinsville, there are partial 

 outcrops of shale and thin bedded sandstone, with a thin coal, probably 

 No. i of the preceding section, aud south-west of the towu, and about 

 three-quarters of a mile from it, there is a partial outcrop of the lower 

 portion of the limestone in the bluff on the east side of the North Fork 

 valley, where we obtained numerous fossils belonging to this horizon. 



West and north-west of Martinsville no rocks are exposed in the bluffs 

 of the creek for some distance, but higher up partial outcrops of a sand- 

 stone, probably overlaying the Quarry creek limestone, may be found. 



At Quarry creek, about a mile and a half south of Casey r , on sec. 28, 

 T. 10, E. 14, this limestone appears in full force, aud has been exten- 

 sively quarried both for building stone and the manufacture of quick- 

 lime. It is here a mottled gra.y, compact limestone, locally brecciated, 

 and partly in regular beds from six inches to two feet or more in 

 thickness. At least 25 to 30 feet of limestoue is exposed here, and as 

 the overlaying sandstone is not seen, its aggregate thickness may be 

 even more than the above estimate. At its base the limestone becomes 

 thin bedded and shaly, passing into a greenish calcareous shale with 

 thin plates aud nodules of limestone, abounding in the characteristic 

 fossils of this horizon. At one point on this creek a bed of green shale, 

 about two feet in thickness, was found iutercalated in the limestone. 

 A large amount of this stone was quarried here for lime, for macada- 

 mizing material and for bridge abutments on the old Natioualroad, and 

 this locality still furnishes the needed supply of lime aud building stone 

 for the surrounding country. 



At the base of the limestone here there is a partial exposure of 

 bituminous shale and a thin coal, probably representing the horizon of 

 No. -1 of the preceding section, below which some ten or twelve feet of 

 sandy shale was seen. 



