STRATIGRAPHY AND STRUCTURE CASTLETON AREA VERMONT

ut in many places a gradational contact between the two requires
arbitrary definition. The Mettawee has been mapped where the siliceous,
poorly cleaved slates of the upper Bomoseen give way to soft, light-green
roofing slate. In a few localities along the Poultney River one or more
3- or 4-foot brilliant white quartzite beds are placed at the top of the
Bomoseen. These may represent the zone of the Diamond Rock quartzite
(Cushing and Ruedemann, 1914, p. 70), which is typically exposed near
Troy, New York. Mettawee lies directly above these quartzite ledges.
In this area 100 to 300 feet of Mettawee are exposed. Dale found
200-240 feet generally throughout the slate belt. Larrabee reported a
thickness of 90-200 feet in the vicinity of Poultney. The probable correlative
of the Mettawee in the Albany area (Ruedemann, 1930), the
Troy shale, is 25-100 feet thick.
Age: Some of the tube-like fossils in the limestone conglomerates
suggest Hyolithellus. Dale (1899, opp. p. 78) listed the following fossils
from the Cambrian roofing slates (Mettawee): Olenellus; Microdiscus
lobatus; M. speciosus; M. connexus; Soleno pleura, possibly nana; Obolella;
Ipijidea pannula; Hyolithes communis; Hyolithellus micans; trails of
annelids. A Lower Cambrian age is clearly demonstrated.
Eddy Hill Grit
Name: This formation derives its name "from Eddy Hill, near Fairhaven,
Vermont, where it rests on the Mettawee slate and carries fragments
of the Olenellus fauna" (Cushing and Ruedemann, 1914, p. 69).
Distribution: Three small outcrops of Eddy Hill grit are located
within an area of one square mile 2.5 miles northeast of the village of
Hampton, New York.
Description: Dale (1899, opp. p. 178) defined his Black Patch grit, to
which the Eddy Hill is identical, as "a dark gray grit or sandstone with
black shaly patches and calcareous nodules." The grit strongly resembles
some beds in the Normanskill formation. A few feet east of the main
highway about 4 miles north of Poultney a white quartzite in beds up to
4 feet thick includes some siliceous conglomerate containing h-inch
angular fragments of green shale. Beds of green shale are interbedded
with quartzites. Under the microscope this rock contains fresh oligoclase-
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