| Symbol | Grain size | Abbr. | Definition/description | Code |
|---|---|---|---|---|
| Clay | C | Clay:silt ratio >2:1 and clay+silt >90%, sand <10%, gravel <2% | 10 |
| Organic mud | - | Clay:silt ratio from 1:2 to 2:1 and clay+silt >90%, sand <10%, gravel <2%. High content of organic material. | 15 |
| Mud | M | Clay:silt ratio from 1:2 to 2:1 and clay+silt >90%, sand <10%, gravel <2% | 20 |
| Sandy clay | sC | Clay:silt ratio >2:1 and clay+silt >50%, sand <50%, gravel <2% | 30 |
| Sandy mud | sM | Clay:silt ratio from 1:2 to 2:1 and clay+silt >50%, sand <50%, gravel <2% | 40 |
| Silt | Z | Clay:silt ratio <1:2 and clay+silt >90%, sand <10%, gravel <2% | 50 |
| Sandy silt | sZ | Silt:clay >2:1 and clay+silt >50%, sand <50%, gravel <2% | 60 |
| Clayey sand | cS | Sand >50%, clay:silt ratio >2:1 and clay+silt <50%, gravel <2% | 70 |
| Muddy sand | mS | Sand >50%, clay:silt ratio from 1:2 to 2:1 and clay+silt <50%, gravel <2% | 80 |
| Silty sand | zS | Sand >50%, silt:clay ratio >2:1 and clay+silt <50%, gravel <2% | 90 |
| Fine sand | - | Sand >90%, includes fine and very fine sand (Wentworth, 1922) | 95 |
| Sand | S | Sand >90%, clay+silt <10%, gravel <2% | 100 |
| Coarse sand | - | Sand >90%, includes medium, coarse and very coarse sand (Wentworth, 1922) | 105 |
| Gravelly mud | gM | Sand:silt+clay ratio <1:9, gravel 2-30% | 110 |
| Gravelly sandy mud | gsM | Sand:silt+clay ratio from 1:9 to 1:1, gravel 2-30% | 115 |
| Gravelly muddy sand | gmS | Sand:silt+clay ratio from 1:1 to 9:1, gravel 2-30% | 120 |
| Gravelly sand | gS | Sand:silt+clay ratio >9:1, gravel 2-30% | 130 |
| Muddy gravel | mG | Gravel 30-80%, sand:silt+clay ratio <1:1 | 140 |
| Muddy sandy gravel | msG | Gravel 30-80%, sand:silt+clay ratio from 1:1 to 9:1 | 150 |
| Sandy gravel | sG | Gravel 30-80%, sand:silt+clay ratio >9:1 | 160 |
| Gravel | G | Gravel >80% | 170 |
| Gravel, cobbles and boulders | GB | Dominant grain sizes are gravel, cobbles and boulders | 175 |
| Cobbles and boulders | B | Dominant grain sizes are cobbles and boulders | 180 |
| Sand, gravel and cobbles | SGB | Dominant grain sizes are sand, gravel and cobbles | 185 |
| Sand and boulders | SB | Dominant grain sizes are sand and boulders | 190 |
| Diamicton | D | Sediment containing particles of a wide range of sizes. Unsorted or very poorly sorted. | 200 |
| Mud/sand with cobbles/boulders | - | Bimodal bottom type where cobbles and boulders occure frequently in the areas dominated by fine-gained sediments. | 205 |
| Cobbles and boulders with sediment cover | - | Very coarse sediments covered by fine material. | 210 |
| Compacted sediments or sedimentary bedrock | - | Submarine outcrop of compacted sediments or sedimentary bedrock. | 300 |
|
Thin or discontinuous sediment cover on bedrock. Sediments with varying grain size. | - | Lateral variation of small basins with sediments and exposed bedrock, and/or bedrock with thin/discontinuous sediment cover. Sediments in small basins may have varying grain size. | 1 |
| Exposed bedrock | - | Areas without sediment cover | 5 |
|
Unspecified | - | Grain size is not specified | 0 |
| Navn (norsk) | Name (english) | Diameter (mm) |
|---|---|---|
| Leir | Clay | <0,002 |
| Silt | Silt | 0,002 - 0,063 |
| Sand | Sand | 0,063 - 2,0 |
| Grus | Gravel | 2,0 - 64 |
| Stein | Cobble | 64 - 256 |
| Blokk | Boulder | >256 |
| NGU | Mareano |