Mississippian copper plates, or plaques, are plain and repousséd plates of beaten copper crafted by peoples of the various regional expressions of the Mississippian culture between 800 to 1600 CE. They have been found as artifacts in in the American Midwest and Southeast. The plates, found as far afield as Florida, Georgia, Illinois, Mississippi, Oklahoma, Tennessee, and Wisconsin, were instrumental in the development of the archaeological concept known as the Southeastern Ceremonial Complex. Some of the..
Igneous rock (derived from the Latin word ignis meaning fire) is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either a planet's mantle or crust. Typically, the me..