Unified Soil Classification System group symbol. For example, GW-GM corresponds to "well-graded gravel "with silt"." If the soil has more than 15% by weight retained on a #4 sieve (R > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt" or "poorly graded SAND with silt and gravel." Unified Soil Classification System The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size
Granular dogfish 450 m depth. Granular dogfish The granular dogfish, "Centroscyllium granulatum", is a little-known, very small dogfish shark of the family Etmopteridae, endemic to the Falkland Islands. The granular dogfish has no anal fin, two dorsal spines with the second one much larger than the first, a large second dorsal fin, a long abdomen, small pectoral and pelvic fins, a large eye, prominent nostrils and spiracles, and brownish-black coloration. It is very small, growing to only 28 cm. They have only been found around the Falkland Islands in the South Atlantic. Almost nothing is known about this shark. It has been