Archaeological stone, studying

Bones and teeth, however, are primary archaeological materials and are common to many archaeological sites. Bones bearing cut marks from stone tools are a clear proxy for human occupation of a site, and in the study of human evolution, hominid remains provide the primary archive material. Hence, many attempts have been made to directly date bones and teeth using the U-series method. Unlike calcite, however, bones and teeth are open systems. Living bone, for example, contains a few parts per billion (ppb) of Uranium, but archaeological bone may contain 1-100 parts per million (ppm) of Uranium, taken up from the burial environment. Implicit in the calculation of a date from °Th/U or Pa/ U is a model for this Uranium uptake, and the reliability of a U-series date is dependent on the validity of this uptake model. 

Williams-Thorpe, O., Potts, P. J., and Webb, P. C. (1999). Field-portable non-destructive analysis of lithic archaeological samples by X-ray fluorescence instrumentation using a mercury iodide detector Comparison with wavelength-dispersive XRF and a case study in British stone axe provenancing. Journal of Archaeological Science 26 215-237. 

Written records provide a valuable glimpse into the thoughts and behavior of ancient peoples. But these records are not complete and omit important information (important, that is, to historians). Scientists studying the past have had to turn to other sources such as analyzing artifacts. Archaeological finds are a rich source of information, if that information can be unlocked. The need is to find a Rosetta stone for other types of artifacts—a method of gleaning all the information that is available. 

Marine shell beads are a regular component of the Holocene archaeological record in many areas of the world. Although they rarely outnumber more common artifacts, such as flaked stone and ceramics, they are sufficiently ubiquitous to have been the subject of considerable archaeological research. Such studies focused on both the symbolic aspects of beads (e.g., wealth display) and the reconstruction of prehistoric trade and/or exchange systems. 

This chapter is an overview of the wide variety of archaeological studies conducted by chemists. From the earliest stone artifacts to the artistic manuscripts and textiles of the more recent past, the studies presented in this volume show the wide range of materials that have been studied by chemical techniques. The field keeps expanding as chemists help provide information valuable in the interpretation of archaeological sites and artifacts. Besides helping to detect fraudulent artifacts and artistic objects in museum collections, chemists have studied the physicochemical deterioration processes that destroy the monuments and objects of the past. Thus, the role of chemists is more than just discovery of the past it includes investigation that may help preserve the artifacts for future generations to enjoy and study. 

STUDY AND RECONSTRUCTION OF EARLY CULTURES usually rely upOU whatever evidence can be recovered from their archaeological contexts. Pottery, stone, and metal artifacts often form the basis for the knowledge of how people lived and worked in the past. Textile fabric products, however, function in much closer associations with people than do the more durable implements. As a result, these products contain valuable information about those who produced, used, and ultimately discarded them. Nevertheless, except in a few rather well-known cases, textile fabrics do not survive the vicissitudes of environmental conditions that follow the final textile use and encourage decay. 

Research in the laboratory usually involves the study of the composition and source of different kinds of materials to answer archaeological questions about past human behavior. The lab methods involve the trace element and isotopic analyses of bones, stone, ceramics, and sediments and have expanded to include organic residues, lithics, pigments, and other materials. Research questions include past diet, human migration, raw material sources, interaction and trade, and the identification of activity areas on prehistoric sites. 

Of great use in such investigations are artifacts or materials that come from a known location. It is in this area that archaeological chemistry has made an enormous contribution. There are many cases of such movement in exotic materials, often in the form of rare stones or minerals. There were no natural sources of turquoise in ancient Mexico, for example, but tins beautiful blue-green stone was imported from the present state of New Mexico and used in the costumes and jeweliy of the elite in Aztec Mexico.. Archaeological chemistry had documented the sources of turquoise in the southwestern and found objects from Mexico that clearly came from those quarries. This example is discussed in more detail in Chap. 8, Case Studies. 

Case studies of functional investigations in archaeological chemistry described here include two of the most common classes of archaeological remains - the microscopic analysis of early stone tools and the application of organic chemistry to determine what pottery was used for by hunter-gatherers in prehistoric Denmark. There are many other studies, not discussed here, regarding the use of prehistoric artifacts and structures to be found in the archaeological literature. 

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