STRATIGRAPHY AND STRUCTURE CASTLETON AREA VERMONT

genera as Olenellus, Nisusia, Kutorgina, Ptyclzoparella, and Bonnia
have been found in the Dunham farther north by several geologists.
Monkton Quartzite
Name: Arthur Keith originally described this formation (1923, p.
107) from Monkton, Vermont, believing it to be contemporaneous
with the Cheshire quartzite.
Description: In this area the Monkton contains fine- to coarse-grained
pink, cream-colored, bone-white, and red ferruginous quartzite in beds
from a few inches to a dozen feet thick separated by various thicknesses
of gray dolomite. Quartzites in some places have dolomitic cement
which, where exposed to weathering, dissolves and leaves behind punky
sandstone. Some excellent ripple marks and mud cracks are evident on
dip slopes.
Distribution and thickness: Inasmuch as only two exposures of undoubted
Monkton are found in the Castleton quadrangle, this discussion
must be speculative. Near the northern border of the quadrangle about
250 feet of Monkton are exposed along the Rutland Railroad. The
Monkton elsewhere in the vicinity of Pittsford is evidently concealed
except for a few thin pink quartzites east of Furnace Brook, which may
represent the Monkton. Monkton crops out at the southern border of
the quadrangle, and thin pink quartzites appear under overthrust
Mendon beds east of Chippenhook. It is likely, therefore, that the Monkton
thins to a few feet or a feather edge eastward and southward in the
Pittsford area. In the vicinity of Chippenhook, however, the Monkton
may thin from about 200 feet in the south to 50 feet or so northward
and eastward.
Age: Kindle and Tasch recently (1948) reported from the Monkton 60
miles north of the Castleton area 4 species of Olenellus and representatives
of the following Lower Cambrian genera: Bonnia, Antagmus,
Kutorgina, Nisusia, Paterincz, Acreteta, Helcionella, Hyolithes, and
Scolithus. The Monkton is probably equivalent to the lower part of the
Parker slate of northwestern Vermont.
Winoosbi Dolomite
Name: Cady (1945, p. 532) revised the term Winooski, as originally
employed by Hitchcock (1861, p. 329), to apply to the "dolomitic beds
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