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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Oak Point Granite
  • Modifications:
    • Named
    • Geochronologic dating
  • Dominant lithology:
    • Granite
  • AAPG geologic province:
    • New England province
Publication:

Brookins, D.G., and Spooner, C.M., 1970, The isotopic ages of the Oak Point and Stonington Granites, eastern Penobscot Bay, Maine: Journal of Geology, v. 78, no. 5, p. 570-576.


Summary:

Named the Oak Point Granite in Penobscot Bay, coastal south-central ME. Unit was dated by Rb-Sr (whole rock) as 357+\-1 Ma and therefore Mississippian (or latest Devonian). The Oak Point is older than the Stonington Granite.

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


Map showing publication footprint
  • Usage in publication:
    • Oak Point Granite*
  • Modifications:
    • Overview
    • Age modified
    • Geochronologic dating
Publication:

Stewart, D.B., and Tucker, R.D., 1999, Geology of northern Penobscot Bay, Maine; with contributions to geochronology: U.S. Geological Survey Miscellaneous Investigations Series Map, I-2551, 1 sheet, scale 1:62,500


Summary:

Oak Point Granite in northern Penobscot Bay consists of light-reddish-gray to brick-red, medium-grained, coarsely porphyritic hornblende-biotite granite with subhedral phenocrysts of flesh-colored microcline and cream-colored oligoclase. Angular inclusions of country rock are numerous. Mississippian age is based on Rb-Sr whole-rock age of 349+/-1 Ma, recalculated from Brookins and Spooner (1970).

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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