Gray to dark-gray, calcareous stony to sparsely stony clay diamicton occurring in the lower West Canada and Mohawk Valleys here named West Canada till. Clasts are predominantly shale and limestone, but metamorphic and dolostone clasts are present. Part of the West Canada formerly assigned to the Maltanner till (here abandoned). Unconformably underlies Hawthorne till (first used) and overlies White Creek till (first used). Interfingers with Newport beds (first used). Deposited during the Nissouri Stade.

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

Middleville Formation here newly defined to include all of the pre-Valley Heads deposits currently identified in the West Canada Valley, east-central NY. These include the basal White Creek Diamicton (new name), the lower Newport Beds (new name), the West Canada Diamicton (new name) and the upper Newport Beds. Term diamicton used rather than till because it refers to a nonlithified, poorly sorted mixture of clay to boulders and best describes the deposits in the West Canada Valley. The first Mohawk Lobe readvance in the West Canada Valley deposited the West Canada "A" Diamicton, a unit limited in extent to between Middleville and Newport, and located within the lower Newport Beds. A second larger Mohawk Lobe readvance deposited the West Canada Diamicton from south of Middleville to northwest of Newport. This diamicton separates the lower Newport Beds from the upper Newport Beds in this region. Middleville Formation is at least as old as the Nissouri stadial (>15.5 ka).

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