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Open-File Report 03-225: Figure 3

Bedrock Lithology Groups by Rock Group B categories

Figure 3. Bedrock Lithology Groups by Rock Group B categories. This figure portrays the dominant lithology of the map units shown on the bedrock geologic maps covering the states of New England, categorized by Rock Group B classification. The Rock Group B categories are listed below:

  1. Unconsolidated Sediments (areas in the south-coastal part of New England where crystalline bedrock is overlain by Cretaceous marine sediments and thick deposits of glacial sediments)
  2. Basin Sediments (2 categories)
    1. Mesozoic Basin sediments
    2. Narragansett Basin sediments
  3. Granitic Rocks (6 categories)
    1. Alkali Granites (White Mountain Igneous Province)
    2. Peraluminous Granites of late Devonian and younger age
    3. Avalon Granites in Avalon Province
    4. Grenville Granites in Grenville Province
    5. Granites in Coastal Maine Province
    6. Other Granites
  4. Felsic Volcanics
  5. Mafic Rocks and their metamorphic equivalents (3 categories)
    1. Basalt
    2. Ultramafic rocks
    3. Other mafic rocks
  6. Metamorphic Rocks (6 categories)
    1. Calcareous Protolith
      1. Carbonate rocks
      2. Calcpelites
      3. Calcgranofels
    2. Pelitic rocks
    3. Sulfidic Schists
    4. Other metamorphic rocks

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