Dark-gray to steel-bluish-gray vitreous quartzite in beds as much as 10 m thick but commonly less than 1 m thick. Resembles quartzites of the Ottauquechee Formation (Cobq). Part of the metasedimentary host rocks of the North River Igneous Suite. Rocks of the Early to Late Taconic Accreted Terrane of the Rowe-Hawley Zone. Eastern allochthonous sequence, oceanic and accretionary realm, ultramafic inclusions, volcanic-arc intrusives, and volcanic rocks.