U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Bass Islands

Usage:

Bass Islands Dolomite (MI*,OH*,PA*)
Bass Islands Formation (WV)
Bass Islands Formation of Hunton Group (KY)
Bass Islands Group (OH*,PA,MI)


Subunits:

GROUP STATUS (alphabetical): Bertie Dolomite (PA), Cobleskill Limestone (PA), Greenfield Dolomite (OH*) or Greenfield Formation (OH), Put-in-Bay Dolomite (MI,OH*), Raisin River Dolomite (MI,OH*), St. Ignace Formation (MI), Tymochtee Formation (OH).
FORMATION STATUS (alphabetical): Greenfield Member (OH), Put-in-Bay Member (MI*), Raisin River Member (MI*,OH).


Geologic age:

Late Silurian*


Type section, locality, area and/or origin of name:

Named from group of islands in western Lake Erie (Lane and others, 1909).


AAPG geologic province:

Michigan basin*
Appalachian basin*


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

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).