Artifact Analysis Effectiveness Of Energy-Dispersive X-Ray Fluorescence Method

There are numerous methods in archaeology to analyze the excavated artifacts from the fieldwork. Energy-dispersive X-ray Fluorescence (ED-XRF) is one of the most effective chemical methods that help archaeologists find out the chemical makeup of the ancient manufactures and relics. ED-XRF makes use of the X-ray spectrum emitted by a solid sample bombarded with a focused beam of electrons to obtain a localized chemical analysis. This method does not harm the artifact itself, thus becoming popular among archaeologist who want to analyze the ancient artifacts without damaging them. Professor Patrick V. Kirch from UC Berkeley and researcher Zofia Stos from Oxford University discuss the application of ED-XRF in their research paper.

In Kirch’s paper “Interpolity Exchange of Basalt Tools Facilitated Via Elite Control in Hawaiian Archaic States”, he mentioned that according to ethno historic accounts, “Late precontact Hawaiian archaic states emphasize the independence of chiefly controlled territories based on an agricultural, staple economy.” (Kirch 2011:1056) However, he has questioned the authenticity of Hawaiian economy by pointing out “the elite control of unevenly distributed resources, such as high quality volcanic rock for adze production, may have provided an alternative source of economic power” (Kirch 2011:1056). Along with other researchers, Kirch tried to use non-destructive energy-dispersive X-ray fluorescence to analyze 328 different lithic artifacts from 36 archaeology features in the Maui island. The results from the EDXRF analysis show that though 71% of the lithic tools were originated from sources on the island, 27% of the artifacts came from sources off the island (Kirch 2011:1059). These results suggest that these territories imported over 25% of their lithic tools even though they were capable of creating their own tools, which do not match with the traditional interpretation that the trade between Hawaiian archaic states seldom occurred (Kirch 2011:1060).

Copper slag heaps and copper ores are useful indication of ancient manufactures for archaeologists. Even small amount of these slags and ores can provide archaeologists valuable information about ancient handicraft industry and people’s living stands. As discussed in Zofia Stos and Noel Gale’s paper “Lead Isotope and Chemical Analyses of Slags from Chrysokamino”, the experiment was aim to explore more about the chemical make up of copper slag and copper ores in Chrysokamino through the use of energy-dispersive X-ray fluorescence. They use the data from ED-XRF to obtain useful information about the copper smelting techniques used at a particular site. The result shows that Chrysokamino is the only site found on Crete so far where copper smelting, the extraction of copper from ores rather than the making of artifacts from copper metal, was practiced. Accompanied with other surveys, the researchers were able to conclude that there are enough copper ore deposits on Crete to have satisfied Minoan demands for this metal in the Early Bronze Age and Crete probably should not be considered a major producer of copper in the Bronze Age (Zofia Stos and Noel Gale, 302).

Both papers described the use of the same chemical method for material analysis, energy-dispersive X-ray fluorescence. This method allowed researchers to distinguish all the elements in one specific sample, helping them to find the exact location where the sources came from. Consequently, the composition of the manufactures and relics are easier to explore. More importantly, this analytic tool is non-destructive, which allow the archaeologist to understand the origin of the artifacts without damage them first. Many of other chemical analysis methods are destructive, either damage the artifact itself or destroy its chemical composition, preventing archaeologists to obtain the exact information from the sample they got. Energy-dispersive x-ray fluorescence does not harm the sample being analyzed. Thus, these ancient manufactures and relics can be preserved while offering useful information to its chemical make up at the same time. Besides its non-destructiveness, ED-XRF also has other benefits. It is a comparatively cheaper analytic tool and it is very efficient compares to other time-consuming method so ancient artifacts can be preserved along with providing insight into its own chemical make up. Some samples can be analyzed within only few seconds and ED-XRF requires minimal sample preparation, reducing the cost of analysis. Because of its non-destructiveness, its cost-effectiveness and its efficiency, in future, energy-dispersive X-ray fluorescence can be used vastly for archaeological purpose.

The information about Hawaiian social and economic society was reflected by ED-XRF analysis of Hawaiian lithic tools. The traditional Hawaiian economy at that time was based on regional autonomy. There were few trades or exchange between states and their primary economic power is the production of crops. Such information allow the archaeologist to conclude that Hawaii states in 18th century were not completely self-sufficient. They also relied on the outside sources such as the lithic resources. To prove this hypothesis, the researchers can analyze either the lands used for agriculture or the farming tools at that time. Thus, ED-XRF is a very useful analytic tool for archaeologist to interpret the archaeological environment and evidences. These two articles presented a few similarities. The first and foremost similarity was Energy-dispersive X-ray fluorescence, the chemical method used to analyze the artifacts. Both articles discuss about the use of EDXRF to analyze the manufactures and relic’s original sources. Such method provides useful data to both archaeological teams, which allow them to make precise conclusions based on the data offered by EX-XRF. With the same chemical analysis method, both team were able to predict the archaeological environment and original sources of the excavated artifacts.

Besides their similarities, there are also some differences between these two paper. For example, the location of each experiment was entirely different. One happened in Hawaii and the other one happened in Chrysokamino. Thus the features of the excavated manufactures and relics were different, causing the result of ED-XRF being different. In Kirch’s paper, the lithic tools were made of one singular rock type, basalt and in Stos’ paper, the copper slags and copper ores were made of different minerals. Another difference between these two paper is the time periods that were explored. Most of the lithic tools in Hawaii were can be dated back to the time period before the contact between the Europeans and Hawaii was established (Kirch 2011, 1056). However, the copper slags and copper ores uncovered in Chrysokamino can date far back to early Bronze Age. Such time discrepancies prove the usefulness of ED-XRF as a chemical analysis method for archaeological use.

Indeed, energy-dispersive X-ray fluorescence is a great method used by a lot of archaeologist when trying to analyze the chemical composition of ancient manufactures. However, there are other method that can also be used to study these artifacts. For instances, radiocarbon dating can be used to determine the age of the artifact containing organic material by using the properties of radiocarbon. Neutron activation analysis (NAA) is also an excellent that can be used to analyze the concentrations of elements in a vast amount of artifacts. All these lines of archaeological evidences can be used to support the authors’ conclusions about society based on chemical analyses.

In short, both articles have demonstrated the usefulness of ED-XRF in archaeological research. In future, such technique can be prevalently used when there’s a need for analyzation of artifacts’ chemical composition. Because ED-XRF keeps the artifacts intact, it is safer to this method than others. With the help of ED-XRF, archaeologists are able to make better progress on their archaeological researches.