Sedimentary > Clastic > Mudstone > Shale
Sedimentary > ChemicalKirkland Hematite, Westmoreland Hematite
Sedimentary > Clastic > Conglomerate
Sedimentary > Clastic > Sandstone
|Comments||0-350 ft. (0-110 m). Secondary unit description from USGS website (ref. NY046) and reference NY033: The Willowvale Shale is exactly equivalent to the Williamson Shale because both are bounded by the same biostratigraphically-dated discontinuity surfaces. Earlier correlations of the upper Willowvale with the Irondequoit are in error. The Williamson-Willowvale sequence records a major marine transgression with at least one major regressive subcycle. New litho- and biostratigraphic data support Gillette's (1947) original contention that the underlying Westmoreland Hematite is genetically related to the Willowvale. Age of both units is Early Silurian (late Llandoverian) (Lin and Brett, 1988). New biostratigraphic data suggest that unit is the same age (late Llandoverian) as the overlying Willowvale Shale and is zonally distinct from the underlying Sauquoit Shale. Westmoreland is laterally equivalent to Second Creek Bed, a new name for a phosphatic quartz pebble bed with abundant pyrite at the base of the Williamson Shale (Lin and Brett, 1988). Clinton group of Third District of NY defined. Consists of green and black-blue shale, greenish and gray sandstone, red sandstone, often laminated, calcareous sandstone, encrinal sandstone, and red fossiliferous iron ore beds, of which the most prominent member is the shale, the next prominent member is the greenish sandstone, and the third most prominent, the iron ore beds. Characteristic masses of these rocks occur around Clinton, Oneida Co., NY. Underlies Niagara/Lockport group and overlies Oneida or Shawangunk group. Age is Silurian.|
Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, Geologic Map of New York State, consisting of 5 sheets: Niagara, Finger Lakes, Hudson-Mohawk, Adirondack, and Lower Hudson, New York State Museum and Science Service, Map and Chart Series No. 15, scale 1:250,000.
Lin, Bea-Yeh and Brett, C.E., 1988, Stratigraphy and disconformable contacts of the Williamson-Willowvale interval; revised correlations of the late Llandoverian (Silurian) in New York State: Northeastern Geology, v. 10, no. 3, p. 241-253.
USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/
|Counties||Herkimer - Montgomery - Oneida|