Light-tan to whitish-gray, massive vitreous quartzite in beds several meters thick, interlayered with rusty-grayish-brown garnet-muscovitic quartzite and aluminous sericite-muscovite-tourmaline retrograde phyllite. Occurs as a thick unit on Ludlow Mountain, in Okemo State Forest. U-Pb ages of detrital zircons range from 1,359±32 Ma to 1,261±62 Ma, no. 10 (Aleinikoff and others, 2011), and suggest derivation from trondhjemitic gneiss of the South Londonderry Igneous Suite. Part of the aluminous schists and gneisses of the Washington Gneiss and Wilcox Formation and related rocks. Mount Holly Complex paragneiss. Rocks of the Green Mountain and Lincoln Mountain massifs and eastern domes.