Kaolin is one of Georgia's greatest natural resources. According to the U.S. Geological Survey, more than 8 million metric tons of kaolin, with an estimated value of more than $1 billion, are mined annually in Georgia, making it by far the leading kaolin clay-producing state in America.
Kaolin (or china clay) is rock that is rich in kaolinite and is used in making coated paper, plastics, rubber, paints, tile, chinaware, toilets, sinks, pharmaceuticals, cosmetics, rocket nosecones, and many other products because of its very fine particle size, whiteness, chemical inertness, and absorption properties.
Kaolinite is a soft, earthy, usually white clay alumina-silicate mineral that can also be pink-orange-red, yellow, or light orange colors. The pink-orange-red colors indicate higher concentrations of iron oxide. Yellow indicates iron hydroxide.
The United States leads the world in production of kaolin. The largest kaolin deposits in the United States are found in central Georgia's “white gold” belt of 13 counties that lie in a northeast-to-southwest band that parallels the Atlantic Seaboard fall line between Augusta and Macon. This cache celebrates the fact that our area is recognized as the world leader in the mining of kaolin.
Deposits here in central Georgia are of three types: (1) "soft" kaolin, which breaks easily and is soapy in texture; (2) "hard" kaolin, which is more finely grained, difficult to break, and jagged in texture; and (3) "flint" kaolin, which has no commercial value because its high opaline silica content makes it extremely hard.
Kaolin occurs in abundance in soils that have formed from the chemical weathering of rocks in hot, moist climates. Geologists say these central Georgia kaolin deposits were laid down in the Late Cretaceous (about 100 million to 65 million years ago) to Early Paleocene (65 million to 45 million years ago) geological time periods, a time when dinosaurs roamed the earth and the waters of the Atlantic Ocean covered much of Georgia’s southern half. The sediments were derived from deeply weathered crystalline igneous and metamorphic rocks of the Georgia Piedmont Plateau. Feldspar, a major component of granitic rocks such as those at Stone Mountain near Atlanta, is considered the parent material for most of Georgia’s sedimentary kaolin. Those pre-historic sediments were transported by rivers to coastline deltas and to estuarine and back-barrier island locations.
Sea-level changes provided favorable environments for deposition into the lens-shaped geometry of the present-day deposits. Iron and titanium oxides were often deposited along with the kaolin, contaminating it and making much of it unusable for commercial use. The deposition process continued for some 30 to 35 million years. The last invasion of the land by the sea deposited huge amounts of red and brown sands and clays over the kaolin deposits. These later sediments formed the characteristic red clay hills of Georgia. Many of the kaolin deposits were covered with more than 200 feet of the red material, rendering them uneconomical to mine. Here in central Georgia, though, there are enough accessible deposits to make mining feasible, and thus kaolin is a major source of revenue. We would love for you to view the small amount of kaolin at this location. For your safety, please do not make any unauthorized visit to mines, quarries or other kaolin sites in Georgia.
Bibliography:
Schroeder, Paul A. "Kaolin." New Georgia Encyclopedia. 05 June 2014. Web. 19 September 2014.
http://www.britannica.com/EBchecked/topic/311676/kaolin
http://www.georgiamining.org/
http://en.wikipedia.org/wiki/Kaolinite
http://www.sandersville.net/KaolinCapitaloftheWorld.cfm
http://www.indexmundi.com/minerals/?product=kaolin
To log this cache, you must send an email to the cache owner and answer these questions:
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Which type of kaolin do you think this deposit is? (Soft, hard, or flint?)
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How would you describe the colors of the kaolin in this area?
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What do the colors of this kaolin tell you about the impurities in it?
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What does the presence of kaolin in this area indicate about the prehistoric climate here?
Please note that the "No Trespassing" sign is for motorized vehicles! Walkers and bike riders are welcome! Another note: the driveway area is partially washed out now. A better parking place is along the wide shoulder of the road just up the hill from GZ.