The sediment grain size fractions map is based on an estimate of the percentage content of each fraction within each of the standard grain size categories represented in the sediment grain size map. The translation table shows the percentage content per grain size category of four grain size fractions – mud, sand, gravel, cobbles and boulders, rock and hard sediments. It is important to note that the percentage values are indicative estimates and not absolute measured values. These values are used to create maps giving a simplified view of the distribution of each grain size fraction. In the map service these values are grouped and symbolised for ease of use. The sediment grain size fractions maps are intended for use at the same map scale as the original sediment grain size maps they are derived from: detailed 1:10 000 – 50 000, regional 1:100 000 – 250 000. |
Grain size SOSI-code | Grain size SOSI-name | Mud % | Sand % | Gravel % | Cobbles and boulders % | Bedrock and compacted sediments % |
---|---|---|---|---|---|---|
10 | Clay | 100 | 0 | 0 | 0 | 0 |
15 | Organic mud | 95 | 5 | 0 | 0 | 0 |
20 | Mud | 95 | 5 | 0 | 0 | 0 |
21 | Mud with sediment blocks av sedimenter | 80 | 5 | 5 | 10 | 0 |
30 | Sandy clay | 75 | 24 | 1 | 0 | 0 |
40 | Sandy mud | 70 | 29 | 1 | 0 | 0 |
50 | Silt | 92 | 8 | 0 | 0 | 0 |
60 | Sandy silt | 65 | 34 | 1 | 0 | 0 |
70 | Clayey sand | 34 | 65 | 1 | 0 | 0 |
80 | Muddy sand | 29 | 70 | 1 | 0 | 0 |
90 | Silty sand | 19 | 80 | 1 | 0 | 0 |
95 | Fine sand | 5 | 94 | 1 | 0 | 0 |
100 | Sand | 4 | 95 | 1 | 0 | 0 |
105 | Coarse sand | 2 | 96 | 2 | 0 | 0 |
110 | Gravelly mud | 80 | 5 | 15 | 0 | 0 |
115 | Gravelly sandy mud | 60 | 25 | 15 | 0 | 0 |
120 | Gravelly muddy sand | 25 | 60 | 15 | 0 | 0 |
130 | Gravelly sand | 4 | 80 | 16 | 0 | 0 |
140 | Muddy gravel | 30 | 15 | 55 | 0 | 0 |
150 | Muddy sandy gravel | 18 | 27 | 55 | 0 | 0 |
160 | Sandy gravel | 4 | 41 | 55 | 0 | 0 |
170 | Gravel | 4 | 5 | 91 | 0 | 0 |
174 | Gravel and cobbles | 1 | 9 | 45 | 45 | 0 |
175 | Gravel, cobbles and boulders | 1 | 5 | 35 | 59 | 0 |
180 | Cobbles and boulders | 1 | 1 | 15 | 83 | 0 |
185 | Sand, gravel and cobbles | 1 | 33 | 33 | 33 | 0 |
190 | Sand and boulders | 3 | 64 | 3 | 30 | 0 |
205 | Mud/sand with cobbles/boulders | 30 | 30 | 5 | 35 | 0 |
206 | Mud, sand, gravel, cobbles and boulders | 30 | 30 | 15 | 25 | 0 |
210 | Cobbles/boulders covered by slam/sand | 20 | 10 | 0 | 70 | 0 |
215 | Sand, gravel, cobbles and boulders | 1 | 30 | 29 | 40 | 0 |
300 | Compacted sediments or sedimentary bedrock | 0 | 0 | 0 | 0 | 100 |
500 | Bioclastic material (corals, coral reef) | 25 | 25 | 35 | 15 | 0 |
1 | Thin or discontinuous sediment cover on bedrock. Sediments with varying grain size. | 6 | 6 | 5 | 3 | 80 |
5 | Exposed bedrock | 0 | 0 | 0 | 0 | 100 |
0 | Unspecified | - | - | - | - | - |
Last updated 21.03.2025 |
NGU | Mareano |