630 



Report of the State Geologist. 



At the northern end of the railroad cut west of the track is the following 



section : 



No. 1. Mixed drab Birdseye limestone and slate-colored, impure J=\ 

 limestone. A little farther down the track all this zone will be found to 

 have changed to the typical Birdseye limestone. This shows the variation in 

 the lithologic character of the Birdseye when followed only a short distance. 



No. 2. Massive layer of somewhat impure Birdseye limestone Y \ '4 = ^ t - i "- 

 from one foot to one foot and four inches thick. Vertical tubes similar to 

 those in the more typical Birdseye. This layer forms the top of the Birdseye 

 in Mr. White's section. 



No. 3. Clear, bluish-drab, typical Birdseye limestone in two p 5 t-i 6 = Io io- 

 layers. 



No. 4- Black river limestone. Dark, bluish-black, fine grained F 5 l = \l jg- 

 and lumpy, weathering to a grey mottled with blackish spots. Very distiuct 

 line between the base of the Black river limestone and the Birdseye. 



It will be noticed that the above sections do not agree closely with that 

 described by Mr. White. The greater part, if not all, of the eight feet 

 referred by White* to the Calciferous formation is in the zone which has 

 been called, in this paper, transitional from the Calciferous to the Birdseye. 

 Apparently, the ledge of Birdseye limestone below the railroad was not 

 noticed by White, for it is stated that the ten feet between the top of the 

 so-called Calciferous and the base of the Birdseye on the west of the railroad 

 cut is covered by debris. In the railroad cut Mr. White drew the line of 

 division between the Birdseye and Black river limestones through the 

 Birdseye limestone at the top of No. 2 of our section, at the northern end of 

 the cut. White described this stratum, which may be traced for the entire 

 length of the cut, as " a bed one foot thick, somewhat crushed on the 

 surface, which weathers yellow." However, there are five feet of typical 

 Birdseye above this layer which White referred to the Black river limestone 

 as No. 6 of his section and described as " two heavy barren beds of dark 

 colored, compact limestone, five feet" in thickness. When these beds are 

 referred to the Birdseye limestone its thickness is ten feet and ten inches at 

 the northern end of the cut, and nine feet and six inches at the southern end 

 instead of five and one-half feet, as stated in his section. Nos. 7 and 8 of 

 White's section belong in the Black river limestone, for which he gave a 

 thickness of six feet and nine inches. 



* Op. clt., p. 82. 



