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 
(4:99). In the Rochester well the thickness of the Hudson and 
Utica together is given as 598 feet.1 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.227 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 goo 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 state. 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- 
trict (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.”8 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 Am. inst. min. eng. trans. 16:951, 952. 
*Reprint from Can. rec. sci. Oct. 1892, p. 3. 
*Geological and agricultural survey district adjoining Erie canal, 1824, p. 85. 
*First annual report third district, Assembly doc. no. 16, p. 164. 
*Loc, cit. Assembly*doc. no. 200, p. 257. 
7Loc, cit, Assembly doc. no. 50, p. 212. 
“Fourth annual report third district Assembly doc. no. 50, p. 372. 
