Silt semi-arid environments that substantial quantities of silt are produced. Silt is sometimes known as "rock flour" or "stone dust", especially when produced by glacial action. Mineralogically, silt is composed mainly of quartz and feldspar. Sedimentary rock composed mainly of silt is known as siltstone. Liquefaction created by a strong earthquake is silt suspended in water that is hydrodynamically forced up from below ground level. In the Udden–Wentworth scale (due to Krumbein), silt particles range between 0.0039 and 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm (sub-divided up into
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