Geologic Unconsolidated Mineral Substrate surface has no trace of Gravel and is > 50% Mud (particles < 0.0625 millimeters in diameter) with the remainder composed of Sand (particles 0.0625 millimeters to 2 millimeters in diameter).

Addition

S

The CMECS Coarse, Mixed, and Fine Unconsolidated Mineral Substrate Classes and subordinate units use Folk (1954) terminology to describe particle sizes of loose mineral substrates as shown in the ternary diagram in Figure 7.2 . Units with bracketed letters, e.g., [G], [(g)sM], correspond to the labeled polygons in Figure 7.2, using conventions from Folk (1954).

See Also: Implementation Guidance for All Substrate Component Units.

When classifying mixes of two different Gravel Subgroup particle sizes, use combinations of the Subgroup unit names with the overall dominant size first. Examples: Boulder-Cobble, Cobble-Boulder, Cobble-Granule, Pebble-Granule, Granule-Boulder.

When classifying Mixes, or when there is a need to identify specific particle sizes beyond the Subgroup definitions, the Subgroup terms for the Gravel Group (Boulder, Cobble, Pebble, Granule), Sand Group (Very Coarse Sand, Coarse Sand, Medium Sand, Fine, Sand, Very Fine Sand), and Mud Group (Silt, Silt-Clay, Clay) may optionally be substituted for the Group term. Examples: Muddy Sandy Gravel -> Silty Sandy Gravel, Slightly Gravelly Sandy Mud -> Slightly Gravelly Sandy Clay, Gravelly Muddy Sand -> Gravelly Muddy Coarse Sand, Slightly Gravelly Sand -> Slightly Gravelly Medium Sand.

Muddy Substrate

cmecs:CMECS_00001675

Muddy Substrate

Anthropogenic Impact, aRPD and RPD Depth, Benthic Depth Zones, Co-Occurring Elements, Coral Reef Zone, Energy Intensity, Induration, Percent Cover (Fine), Mineral Precipitate, Percent Cover (Coarse), Seafloor Rugosity, Small-Scale Slope, Substrate Descriptor, Substrate Layering, Surface Pattern, Temporal Persistence

Original Unit

CMECS Substrate Component: Substrate Subclass