Monday, April 02 2012
Placer gold is any gold that has been freed from solid rock by weathering. There are several types of placer gold, including Eluvial (gold that has been pulled down hill through the force of gravity), Alluvial (running water has deposited the gold in streams and rivers), and Beach (gold is concentrated by wave action). Eolian placers form by wind action in arid regions. Material broken from the bedrock disintegrates and the winds carry away the surface sand and dust, leaving behind a layer of cement-like mixtures of quartz, schist, and other material. Gold, being heavy, settles in this sun-baked "pavement." For the most part, eolian placer gold can be found just about anywhere in a desert landscape. Look for obvious signs of wind erosion and soil depletion, or a flat area on a wind-blown hillside where vegetation grows. If seeds were trapped in a depression, perhaps gold was, too. Desert miners have learned from experience that since wind has carried away most of the lighter sand and topsoil, eolian gold is usually very close to the surface or even on the surface. You can sometimes spot shiny flakes and tiny pickers practically laying on top of the ground, or a metal detector will find anything that is hidden just below the surface.
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