Soil mechanics necessary to run water through the sieves to wash the coarse particles and clods through. A variety of sieve sizes are available. The boundary between sand and silt is arbitrary. According to the Unified Soil Classification System, a #4 sieve (4 openings per inch) having 4.75mm opening size separates sand from gravel and a #200 sieve with an 0.075 mm opening separates sand from silt and clay. According to the British standard, 0.063 mm is the boundary between sand and silt, and 2 mm is the boundary between sand and gravel. The classification of fine-grained soils, i.e., soils that are
Eye Gravel Pit Eye Gravel Pit Eye Gravel Pit is a 0.4 hectare geological Site of Special Scientific Interest in Eye Green in Cambridgeshire. It is a Geological Conservation Review site, and part of it overlaps Eye Green Local Nature Reserve. This former gravel quarry in the East Anglian Fens has marine and a few non-marine shells laid down when the area was under the North Sea, probably during the warm Eemian period, 130,000 to 115,000 years ago. It is described by Natural England as important because it lies at the junction between fluvial and glacial deposits. The site is private land with