428 NEW YORK STATE MUSEUM 



Chittenango well, 32 miles west of Utica, as 233 feet, below which 

 are 60 feet of transitional shale and limestone. In this well are 640 

 feet of blue argillaceous shale and sandstone referred to the Hudson 

 {4 199) . In the Rochester well the thickness of the Hudson and 

 Utica together is given as 598 feet.^ In the Altamont well about 

 17 miles west of Albany the drill started 595 feet below the base of 

 the Helderberg limestone which caps the Hudson river formation 

 in that vicinity, and passed through 2880 feet of sandstone and shales 

 before reaching the Trenton limestone.^ Mr Henry M. Ami says, 

 " By some of the early writers it [Utica formation] was spoken of 

 as consisting of shaly strata whose total thickness exceeded 900 feet, 

 whilst by others the very humble yet perhaps truer estimate was 

 given ' of about 75 feet in thickness.' "^ 



Hudson river shale. This rock is the Second Graywacke of Eaton 

 which is well developed in the vicinity of Schenectady and in large 

 areas of the stated Mr Conrad named the terrane from its western 

 exposures the " Gray sandstones and shales of Salmon river."^ In 

 the Second report of the third district Vanuxem states that the rock 

 appears " as a dark coloured sandstone in Montgomery [county]^ 

 with but little shale."^ In the Fourth annual report of the first dis- 

 t7'ict (1840) Mather uses the term " Hudson river slate group " 

 which he says consists of " slates, shales and grits with interstrati- 

 fied limestones."^ 



In the same year Vanuxem described under the name of Frank- 

 fort slate " the rock or mass [which] is the successor to the black 

 slate, the one changing to the other by imperceptible gradations, 

 the dark or black color of the lower rock disappearing in the 

 lighter color of the upper rock."^ He also substituted the term 

 Pulaski shales for the shales of Salmon river and added the term 

 Salmon river sandstones for the arenaceous rock above the Pulaski 

 shales (p. 374). 



In his final report Vanuxem clearly states the distinction between 

 the Utica and Hudson river (Frankfort) shales. " The Utica," he 



^Rochester acad. sci. proc. 2:92. 

 -Ashburner Ana. inst. min. eng. trans. 16:951, 952. 

 ^Reprint from Can. rec. sci. Oct. 1892, p. 3. 



^Gcologloal and agricultural survey district adjoining Erie canal, 1824, p. 86. 

 ^First annual report third district. Assembly doc. no. 16, p. 164. 

 ^Loc. cit. Assembly doc. no. 200, p. 257. 

 ''Loc. cit. Assembly doc. no. 50, p. 212. 

 ^Fourth annual report third district Assembly doc. no. 50, p. 37i. 



