State by State

Rhode island

  • Specimen Number

    37

  • Description

    Half-rounded boulder of coarse grained,  slightly pink, granite. Weakly foliated with large, aligned feldspar phenocrysts, suggesting flow before crystallization.

  • Classification

    Igneous. Plutonic. Granitic. Granite. Pink.

  • Location & Occurrence

    Search suggests source is Permian intrusions in southwest such as the Westerly and Narragansett Pier Granites  (~276 +/- 7 Ma UPb). The older Proterozoic granites are highly sheared, and many recrystallized.

  • Geologic Age

    Permian (?)

  • Geoheritage

    Magmas indicate culmination of orogenies resulting in Pangea, the large supercontinent. Best candidate is Alleghenian Orogeny.

  • Links

    Link to State Geological Map from USGS.  Link to Rhode Island Geological Survey.

  • Other

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Specimen stone for Rhode Island.
Closeup of Rhode Island stone. Outline of Rhode Island. Geol Map of Rhode Island.