Pg. 219, 221, etc. Berwyn member of Skaneateles formation. Dark, arenaceous shale overlying Pompey member of Skaneateles. Well exposed in Conklin's Falls (The Cascades) ravine in Butternut Valley, southeast of Syracuse, [Tully quadrangle, Onondaga County, central New York]. At type section the fauna has a "Marcellus or LEIORHYNCHUS facies." Traced westward it becomes argillaceous and fissile. Well exposed at Rose Hill below the Centerfield and in Clintonville ravine, Skaneateles quadrangle, [Onondaga County, central New York]. At both places it grades into Centerfield. Thickness at type section is 200+/- feet. Thins to west to 90+/- feet at Rose Hill. Is 235 feet thick at Hamilton village. To east of type section the "LEIORHYNCHUS facies" becomes less prominent by influx of typical Hamilton fossils as the shales become more arenaceous. At Gould's quarry, in Unadilla Valley, the characteristic LEIORHYNCHUS LAURA is lacking and Hamilton fossils are abundant at top ot section; also the basal 65 to 90 feet of Berwyn has become arenaceous and similar to upper Pompey. Age is Middle Devonian.
[Derivation of name not stated, but probably is village in Tully quadrangle.]

Source: US geologic names lexicon (USGS Bull. 896, p. 173).

Pg. 180-181. †Berwyn member of Skaneateles Shale. Name abandoned. Replaced with Butternut shale member (new) of Skaneateles formation.

Source: US geologic names lexicon (USGS Bull. 1200, p. 317).