Sedimentary, metamorphic and igneous rocks are found in Georgia. The state has four distinct geographic regions, and different types of each rock can be found throughout the land.
The northwest corner of Georgia falls into the Valley and Ridge region. Sedimentary rocks, such as limestone, sandstone and shale, are found here. Barite, ochre and coal have also been mined from this region.
The Blue Ridge region contains the mountains of North Georgia. These rocks are metamorphic, coming from pre-historic sedimentary and igneous rocks. Metagranite, gneiss, mafic, ultramafic and metavolcanic rocks are common in this area.
The middle geographic section of Georgia, the Piedmont, contains metamorphic rocks as well. It also has igneous rocks in some areas. The metamorphic rocks are slightly different from the metamorphics found in the Blue Ridge region. Rocks in this portion of the state include schist, gniess, amphibolites, migmaties, and the igneous granites. Granite is mined from this area, and the granite "Stone Mountain," a tourist attraction, was formed by the same granite veins that traverse the region.
The Coastal Plain region contains mainly sedimentary rocks, with metamorphic and igneous rocks underneath. Limestone, sandstone and shale are found here, and the beaches contain white quartz. Kaolin is mined in this region, as are limestone formations.Learn More
Igneous rocks rarely contain fossils because the formation of a fossil requires sedimentation. A fossil results when the remains of a plant or animal are covered by sediment that hardens, forming the mold that eventually fills with minerals. Igneous rocks form under heat and pressure that destroy organic remnants.Full Answer >
According to About.com, agate forms from the deposition of silica in aqueous solution at low water depths and relatively low temperatures. It is a form of chalcedony mineral, which is a mass of quartz composed of microscopic crystals. Its porous nature, relative to other forms of quartz, allows it to develop impurities that give it a variety of colors and patterns, making it a popular stone for use in jewelry.Full Answer >
Marble is a metamorphic rock formed from limestone. Changes in the limestone's chemical properties due to external forces can result in the creation of marble.Full Answer >
In geology, polymorphs occur when two compounds of the same composition have different crystalline structures. An example of a polymorph is quartz that is subjected to high temperatures, transforming to trydimite and then crystobalite. Trydimite and crystobalite are considered polymorphs of quartz.Full Answer >