CD. Walcott — The Taconic System of Emmons. 317 



were identical, and that d' was a mass of the Calciferous 

 sandrock of the New York section, and, also, the mass repre- 

 sented by. c. I began the investigation of this section, in 1887, 

 by searching for fossils in the various formations, and then 

 studied its stratigraphy. The result is given in the section 

 represented by fig. 12. I found that the blue limestone, e, of 

 figs. 11 and 12, extends beneath the shales and limestones cap- 

 ping the mountain and that it is interbedded in the shales and 

 considerably broken and displaced on the south edge of the 

 mountain, toward the fault line, as shown in fig. 12. Leper- 

 ditia fdbulites was found in it, on both the west and south 

 side of the mountain. The true Calciferous sandrock, of the 

 New York section, is shown at E, interbedded in the shales, S 

 and X. In the limestones, d, forming the summit of the 

 mountain, in fig. 11, I found Lingulella ccelata, Linnarssonia 

 Taconica, Obolella sp. undet., Hyolithellus micans, Microdis- 

 cus speciosus and Olenellus Thompsoni : all of which are Mid- 

 dle Cambrian species and characteristic of the slates, b", in fig. 

 11, east of the mountain. Dr. Emmons identified this mass of 

 strata, d', with the Galciferous sandrock on lithologic characters, 

 overlooking the fact that a similar rock might occur in his 

 Taconic series. Two miles to the north, on the farm of D. 

 Walker Reid, this belt of calciferous rock is over 600 feet 

 thick, it contains a characteristic Middle Cambrian fossil, Hyo- 

 lithellus micans, and is conformably subjacent and superjacent 

 to shales and limestones, containing over fifteen characteristic 

 species of Middle Cambrian fossils. 



Figure 12. — Section of Baltl Mountain from the south. The profile of the 

 mountain and position of the Cambrian and Lower Silurian rocks are taken from 

 a photograph. The " Upper Taconic "=Carabrian slate, sandrock and limestone 

 are shown to the right of the fault, and c=Chazy limestone ; x — dark shales, 

 interbedded between c and the Calciferous sandrock, E ; s=dark argillaceous 

 shales beneath the Calciferous sandrock. 



The section of Bald Mountain proves that the strata of the 

 " Upper Taconic " are there pushed over on to the Chazy Ter- 

 rane, and that the " Upper Taconic " is not unconformable sub- 

 jacent to the latter or to the Calciferous sandrock. 



To the north of Bald Mountain, about two miles, a somewhat 

 similar mass of limestone to that of c is adjacent to the fault 



