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Map showing publication footprint
  • Usage in publication:
    • Tunnels Mill Member*
  • Modifications:
    • Named
  • Dominant lithology:
    • Clay
    • Silt
    • Sand
  • AAPG geologic province:
    • Atlantic Coast basin
Publication:

Mixon, R.B., 1985, Stratigraphic and geomorphic framework of uppermost Cenozoic deposits in the southern Delmarva Peninsula, Virginia and Maryland, IN Surface and shallow subsurface geologic studies in the emerged coastal plain of the middle Atlantic states: U.S. Geological Survey Professional Paper, 1067-G, p. G1-G53, (incl. geologic maps, scale 1:125,000 and 1:400,000)


Summary:

The middle unit of the Yorktown Formation is here named in a 10-mi-wide belt in the subsurface of Accomack Co., VA, and Somerset and Worcester Co., MD. Consists dominantly of greenish- to brownish-gray micaceous clayey silt, silty clay, and fine quartz sand. Gradationally overlies the lower shelly sand member of the Yorktown and gradationally underlies the upper shelly sand member of the Yorktown or unconformably underlies the Accomack Member (new name) of the Omar Formation. Thickness at type section is 62 ft (19 m). Age is middle Pliocene.

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


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

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