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
Dravo Gravel Site Dravo. The inhabitants' technology prompted their classification as a people of the middle of the Late Archaic Period. In 1978, the Dravo site was listed on the National Register of Historic Places, qualifying because of its archaeological significance. Dravo Gravel Site The Dravo Gravel Site (33HA377) is an archaeological site located above the Great Miami River in Miami Township, Hamilton County, Ohio, United States. Discovered in the middle of a gravel pit, the site is a leading example of the local manifestation of the Archaic period. The site lies atop a Miami River terrace outside the village of Cleves, occupying