Usage:
Portland Formation of Newark Supergroup (CT*,MA*)
Portland Arkose of Newark Supergroup (CT*)
Geologic age:
Jurassic, Early*
Sinemurian, late
Pliensbachian
Toarcian, early
Jurassic, Middle(?)
Aalenian(?)
Bajocian(?)
Bathonian(?)
Type section, locality, area and/or origin of name:
Exposures in the Portland "brownstone" quarries near Middletown, Middlesex Co., CT (Krynine, 1950).
AAPG geologic province:
New England province*
Hartford basin*
Pomperaug basin*
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 ([ ]).