WEATHERING OF THE PIEDMONT ROCKS

50-56 million years ago

Weathering of the rocks of the Piedmont generated large volumes of kaolinitic clays, quartz sand and mica, as well as minor amounts of other minerals, especially iron and titanium oxides, such as limonite and anastase. 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.