650 



Report of the State Geologist. 



Feet 

 1C5 = 165 



XL V K x . , Mostly covered-,, but showing brownish weathering, 

 slabby shale in the west bank of Chuctenunda creek, just above Minaville. 

 Utica slate. 



K 2 . Top consisting of slaty layers, containing graptolites in ^255 

 abundance. Below this point the black calcareous shales are exposed to within 

 ! 65 feet of creek level. 



K*. Black shales, becoming olive to blackish at to]). These v J'''\., it 

 shales show a transition from the black, calcareous, slabby shale of the Utica 

 to the arenaceous, thin, crumbling, olive shale of the Hudson river for- 

 mation. Transitional shales. 



IT*. Mostly thin sandstones and arenaceous shales, with a massive 

 two-foot layer at the base in the south branch of the deep glen, This portion 

 of the section comprises the cap of the hill and is mostly covered. Hudson 

 river formation. 



The above section is the only one noticed in this region, which gives the 

 passage from the Utica to the Hudson piver formation, and is of especial 

 interest on that account. Within the limits of a continuous exposure of 255 

 feet of shales, there is exhibited a complete transition from the typical 

 lithologic characters of the Utica to those of the Hudson liver. The Utica, 

 at the lower part of this exposure, is black with brownish streak, and 

 w eathers brown w ith a greenish tint. It is strongly calcareous and disposed 

 in even, well defined layers, w hich usually split into laminae, having smooth 

 Hat surfaces. These, in turn, crumble to square-edged fragments. In some 

 cases, how ever, coherent layers occur from an inch to four or five inches in 

 thickness, which are quite hard and break with a conchoidal fracture. These 

 are the well-known slabby layers of the Utica formation. The shale shown 

 in the upper part of this exposure is blackish to dark olive or grey, very 

 friable, and weathers to a dirty brown. It is not sufficiently calcareous to 

 effervesce with cold acid, and is disposed in layers which break up into 

 irregular laminae w ith uneven rounded surfaces w hich, in turn, weather to 

 small, thin, sharp-edged, usually quadrilateral scales that readily pass into soil. 

 The Graptolite bed is of especial interest and no other fossils w ere found in 

 it. The shales at this point exhibit a combination of the characters of the 

 Utica and Hudson river formations, and the layers split into laminae with 

 irregular surfaces. The difference in altitude between the first exposure of 

 sandstone in this section and the level of the Mohawk at its nearest point, 

 is 740 feet, and the distance is nearly five miles. This indicates a thickness 

 of approximately 1,440 feet, if the dip be 140 feet per mile, as is show 11 to 



