Prosser and Cumings— Lower Silurian Sections. 



JF™. Black, carbonaceous, slabby, calcareous shale, exposed in the 111 , F '' <, ' 0I , 

 creek bed and to the first branch of the creek, not far below the highway 

 north of Adebahr hill. 



F i0 . No rock is exposed in place, but plenty of fragments of ,, S( f"'!; S0 

 calcareous shale occur in the soil of the hillside, becoming especially abundant 

 in a small knoll on the northeastern declivity. 



F". Top of Adebahr hill. Bl ack, crumbling, calcareous shale 14 o F = C 82o 

 with thicker coherent layers exposed in the open pasture on the southern 

 brow of the hill. Below this point covered. The top of Adebahr hill is 

 barometrically 820 feet above the base of the section. The New York 

 Triangulation bench mark, seen on its northern crest, is 1,062 feet A. T. 

 The difference between this and the altitude of the canal at the base <>{' the 

 section is 800 feet. 



The members of the Trenton and Calciferous formations of this section 

 were measured by Mr. Darton in the summer of 1892, and described in 

 1894.* In his section the Birdseye is given as above the Black river. There 

 does seem to be a peculiar blending of the lithologic characters of the mas- 

 sive member of the Trenton and the Black river in Nos. 8 and it of the 

 present section, so that there is not a sharp line between the two subfor- 

 mations. The Birdseye is well defined, however, in its proper stratigraphic 

 position, being sharply separated from the underlying Calciferous, and less 

 sharply, though distinctly, from the overlying Black liver. It contains no, 

 or at least very few, fossils. The upper, thin-bedded member of the Trenton 

 is excellently shown and seems to pass gradually into the Utica slate above, 

 although the line between the two is fairly distinct if drawn where the 

 Trenton fossils cease. The Utica slate is exposed at intervals from Morphy's 

 to the top of Adebahr hill, a vertical distance of 740 feet, with quite con- 

 stant characters, especially the persistence of slabby, calcareous layers. The 

 distance between Morphy's quarry and the bench mark on Adebahr hill is 

 just three miles, hence if the south dip be 140 feet per mile, the actual 

 thickness of Utica in this section is 1,1 60 feet. 



Minaville Section. 



In the slope of the hill, southwest of Minaville, and at a point about one 

 and four-tenths miles south by southwest of the centre of the village, the 

 Utica slate is exposed in several small glens. A section was measured be- 

 ginning at the level of Chuctenunda creek and extending to the top of the hill. 



* Thirteenth Annn.nl Report of the State fieologist [New York], pp. 42G, 127. 



