STRATIGRAPHY AND STRUCTURE CASTLETON AREA VERMONT

andesine grains, slate fragments similar to the surrounding Cambrian
formations, grains of carbonate, and secondary shreds of chlorite and
sericite, in addition to dominant quartz grains of all sizes. This rock is
more properly called a graywacke. It lies between Mettawee and Schodack,
and, although not typical, it is without doubt Eddy Hill.
Thickness and age: This formation is discontinuous and lens-like with
a maximum thickness of about 30 feet. Only a few exposures were
encountered during mapping. No fossils other than those found by T.
N. Dale and quoted above have been reported from the Eddy Hill, but,
located as it is between two fossiliferous formations, its age is obviously
Lower Cambrian.
Schodack Formation
Name: From the well-known fossiliferous exposures two miles south
of Schodack Landing on the Hudson River and the belt of these rocks
in the town of Schodack, New York, Cushing and Ruedemann (1914,
p. 70) named the Schodack shales and limestones. This unit is Dale's
Cambrian black shale. In accordance with modern usage the unit is
here called the Schodack formation. Unfortunately more recently the
term "Schodack formation" has been given a special meaning. In 1938
Resser and Howell (p. 204) stated: "The Bomoseen grades upward into
calcareous beds to which Ruedemann assigned the name Schodack and
which Dale called the 'Cambric black shale.' It is possible that Ruedemann's
Mettawee slate (Dale's 'Cambric roofing slate') which crops out
about Greenwich, New York, and in a belt extending from Pawlet to
Fairhaven, Vermont, is also Schodack." This is nonsense; the Mettawee
was defined as equivalent to Dale's division B in the slate belt, and the
Schodack was defined as equivalent to division D. Mettawee is Mettawee,
and Schodack is Schodack. Whether these units can be differentiated
outside the slate belt is beside the point; in the slate belt the
Mettawee and Schodack are entirely different in appearance.
In conference with Resser, Ruedemann (1942a, p. 64) "found that it
would be more practicable to extend the term Schodack so as to include
as members the beds that occur associated or even interbedded with it
such as the Zion Hill quartzite and the Burden conglomerate, and also
the Troy shale and limestone . . . ." Ruedemann said further (p. 65):
"Doctor Resser would unite Ruedemann's Mettawee slate, Schodack
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