Chemical techniques are applied in archeological research to determine the composition and isotopic makeup of biological, natural, and synthetic remains. Chemical and isotopic studies of plant and animal residues are undertaken to investigate ancient diet, nutrition, and resource use. Compositional analysis of natural or synthetic materials and residues is performed to ascertain artifact manufacturing processes and use. Archeological chemistry expertise is used to ascertain the processes that govern the preservation and decay of materials, thus providing valuable information regarding subsequent conservation and restoration. It has also been employed to determine the location of a geographical source of procurement or production of materials used in long-distance contact or trade.