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Rock groups A and B

The dominant bedrock lithologies can be selected by the "Rock Group A" item heading. The Rock Group A category contains 7 lithologic categories and a category for freshwater. Rock Group A can be further divided into more specific lithology groups, in the attribute Rock Group B. The Rock Group B category contains 18 lithologic categories and a category for freshwater. Below is an outline of all the major (A) and minor (B) rock groups.

Rock group A value Rock group B values
basin sedimentary Mesozoic Basin sediments, Narragansett Basin sediments
calcpelite calcpelite
carbonate rocks carbonate rocks
granite Avalon Granite, alkali granite, granite (other), Grenville granite, peraluminous granite, felsic volcanics
mafic rocks basalt, mafic rocks, ultramafic rocks
metamorphic rocks calcgranofels, pelitic rocks, sulfidic schists, metamorphic rocks (other)
unconsolidated sediments unconsolidated sediments
water water

Rock groups and lithogeochemical unit types

The rock group fields categorize the 37 lithochemical units into related groups with differing degrees of detail. Below is a listing of the lithochemical units in each rock group:

Rock group A value Lithogeochemical units
basin sedimentary: 21c, 22u, 23u
calcpelite 13u, 34c
carbonate rocks 11u, 12u, 12g, 12gc, 12gs, 12s, 13u
granite 61u, 61v, 62u, 62n
mafic rocks 41u, 42u, 43u, 43s, 44u, 45u, 50u
metamorphic rocks undivided 11u, 12u, 31u, 31c, 31gs, 31s, 32u, 32c, 2gc, 32s, 33u, 33c, 33cs, 33s, 34u, 34c, 34cs
unconsolidated sediments 70u
water -9999 (none)

Rock Group B (Rock_GpB) with ID (R_GpB_ID) in parenthesis, and the lithogeochemical unit(s) (litho_code + lith_mod) contained in each category:

Rock group B value Lithogeochemical units
carbonate rocks (1) 11u, 12u, 12gs, 12s
calcpelite (10) 13u, 34c
calcgranofels (11) 31c, 32c, 33c, 34c, 34cs
Mesozoic Basin sediments (20) 21c, 22u, 23u
Narragansett Basin sediments (21) 23u
metamorphic rocks, other (3) 33c, 34u, 34c, 34cs, 34s
pelitic rocks (30) 31u, 31c, 31gs, 32u, 32c, 32gc, 33u
sulfidic schists (31) 31s, 32s, 33cs, 33s
mafic rocks (4) 41u, 42u, 43u, 43s, 44u, 45u
basalt (41) 41u
ultramafic rocks (5) 50u
granite, other (6) 61u, 62u, 62n
felsic volcanics (60) 61v
Grenville granite (61) 61u
Avalon granite (62) 61u, 62u
peraluminous granite (63) 61u
alkali granite (64) 61u, 62u, 62n
unconsolidated sediments (70) 70u
water (0) -9999

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