Ottauquechee Formation

Ottauquechee Formation - Black carbonaceous phyllite or schist containing interbeds of massive quartzite commonly criss-crossed by veins of white quartz; quartzite is dark gray and carbonaceous, light gray, or white; also includes light green quartz-sericite-chlorite phyllite or schist and sercitic quartzite; beds of phyllitic graywacke and feldspar granule conglomerate are north of Lamoille River. Schist contains abundant porphyroblasts of garnet and biotite from Ludlow south. The Ottauquechee contains two major units: A black phyllite and the Thatcher Brook Member. The black phyllite contains a previously unreported sub-unit of gray carbonate schist. The Thatcher Brook Member (named in an abstract by Armstrong and others, 1988) is a carbonaceous albitic schist with greenstones and ultramafics. These rocks have previously been included in the Ottauquechee but have never been differentiated from the black phyllite. Member is in fault contact with the silvery green schist of the Pinney Hollow Formation to the west. Age is Cambrian (Ratcliff, in press).