Geology of Eastern New York. — Prosser. 381 
easterly to the Little Falls and Canajoharie region the typical 
Trenton limestone thins rapidly and probably the lower portion 
of what has generally been referred to the Utica shale in this 
latter region was deposited during the same time as that of the 
upper Trenton limestone of the former locality. About Little 
Falls there are alternating beds of limestone and shale which, 
lithologically, are transitional from the Trenton to the Utica. 
These beds are more fossiliferous than the usual Utica shale 
and, possibly, can be referred to the Trenton limestone; or, 
perhaps it will be better to consider them a "zone of Trenton- 
Utica passage beds" as has been done by professor Cushing in 
his geologic map of the Little Falls quadrangle. ' : 
The Helderberg sections. — In the reports of the state Geolo- 
gist of New York the author has published various sections in 
the Helderberg plateau of Albany and Schoharie countii 
Later investigations of other geologists have added to our 
knowledge of these formations and Mr. Schuchert has shown 
that the age of two formations is not that which had generally 
been assigned to them. The Coralline limestone, now named 
the Cobleskill by Dr. J. M. Clarke, was in 1852 correlated by 
Prof. Hall with the Niagara limestone^ while the subjacent 
green pyritiferous shale was, apparently, referred tc the Clinton 
group. This opinion was evidently held by Pro . [all until 
his death for in Mr. Darton ription of the Helderberg 1 
limestones, a report prepared under Professor Hall's direction, 
is a foot note by Flail stating that ''The Niagara ('Corraline') 
limestone crops out along the road going obliquely up the hill 
at the northeasterly end of the village of Schoharie, and con- 
tinues for more than a mile along the northerly escarpment of 
the terrace."?' In the t> 1 Mr. Darton \\~<-<\ the names Niagara 
limestone and Clinton formations with, apparently, Professor 
Hall's acceptance for format I posed al Howe's 
Cave and Schoharie.il In my sections in the vicinity of these 
two villages the correlation of Professor Hall was accepted and 
followed for these two divisions which wen- called the ("linton 
* Letter of Pro r. li. P. Cushing, Feb 17, 1902, 
t "Stratigraphic Geology of the Eastern Helderbergs," Seventeenth An. 
Rep. State Geologist, 1890, (1900), pp, 329-342. the form- 
ations along the northern end of the Helderb au. 18th Ibid L899 
( L90J I, pp. m 7::. 
X Pal A', v.. vol. ii, p. 321. 
§ Thirteenth In Bep StaU Geol., 1894 [1895], p. 218 
i| Ibid . i>. -is : see also plates I, •': and 4. 
