Named Beech member of the Valcour Formation for Beech Bay, Grand Isle Co., VT. Unit is the upper member of the formation and overlies the Hero member from which it differs both lithologically and faunally, being essentially the ROSTRICELLULA PLENA zone. Well exposed beds at Rockwell Bay include principal lithic variants. Basal 35 feet is fossiliferous calcarenite somewhat dolomitized and encarenites, irregularly dolomitized, succeeded by shaly calcargillite with massive zoarea of ANOLOTCHIA sp. and STROMATOTRYPA sp. Upper 51 feet is gray medium- to coarse-grained calcarenite having cross-stratified beds, with ROSTICELLULA, MIMELLA, and ramose trepostromes. Top contact not exposed here but where it is exposed on northern tip of Valcour Island, brown-weathering dolomite is succeeded by "Lowville" calcilutite. Thickness near Rutland Station, South Hero, 86 feet. The Beech member is of Middle Ordovician (Chazyan) age.

Source: GNU records (USGS DDS-6; Reston GNULEX).