THE NIAGARAN FORMATIONS OF WESTERN OHIO 335 



A series of sections at Piqua, along the Stillwater River between 

 Covington and West Milton, and along Ludlow Creek in Miami 

 County, and in the vicinity of Lewisburg, Eaton, and New Paris 

 in Preble County, has furnished the writer the complete section 

 from the Ordovician to the highest Silurian rocks of this area. 



DESCRIPTION OF SECTIONS 



The contact of the Ordovician and Silurian systems is clearly 

 shown at Ludlow Falls, and the succeeding rocks as high as they 

 extend in this region are admirably exposed at the falls and in the 

 series of quarries which border the creek for some distance above 

 the falls. Sections at other localities agree with the ones along this 

 creek and show that the general order of succession is essentially 

 the same for these counties. 



LUDLOW CREEK SECTIONS 



Four of the series of sections measured along Ludlow Creek will 

 be given, which were checked by several other sections along the 

 same stream. From these a general section of the rocks shown 

 along this creek can be compiled. 



The following section is based on the outcrops in the north- 

 eastern corner of the Colonel Samuel B. Smith quarry and the bank 

 at the northern end of Ludlow Falls: 



Section of Ludlow Falls and the Smith Quarry 



Total 

 Thickness 



Thickness 

 No. Feet Inches Feet Inches 



6. Dayton limestone. — Northeast corner of the 

 Colonel Samuel B. Smith quarry. The rock 

 varies from light gray to somewhat darker gray 

 on fresh fracture and some as weathered is 

 bluish-gray. Other layers on the weathered 

 faces are buff to brownish or rusty color from 

 disintegrated iron pyrite. The rock splits into 

 even-bedded layers; but the surfaces of the 

 bedding planes are frequently rather rough and 

 show stylolites structure. The majority of the 

 layers vary in thickness from 2 to 10 inches, 

 most of them ranging from 4 to 6 inches. The 

 lowest layer is from 3 to 4 inches thick, and the 



