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
Mike Gravel run for president. Gravel favors abortion rights. During the 2008 campaign, Gravel was a strong supporter of LGBT rights. He supported same-sex marriage and opposed the Defense of Marriage Act and the U.S. military's "don't ask, don't tell" policy. He wrote in 2008 that "depriving gays and lesbians of equal rights is immoral." Gravel is a critic of what he terms American imperialism. Gravel firmly opposes U.S. military action against Iran and Syria. He voiced opposition to the Guantanamo Bay detention camp, the Military Commissions Act of 2006, the use of torture, indefinite detention, and what he called "flagrant ignorance"