I am a graduate student at the University of Washington, and for the last two summers I have been working on the KBP project in the Kuril Islands as a member of the archaeology team. However, this summer while the rest of the team is in the field again, I am working at the Smithsonian Institution to analyze some of the lithic artifacts that have been excavated over the last two years. Specifically, I am tracing the geologic source of the obsidian artifacts that we have recovered - this is called a provenance study. Obsidian, which is a type of volcanic glass that can be produced when a volcano erupts, is a very useful material for making stone tools. Obsidian creates a very fine and very sharp edge - sharper than the surgical steel used for scalpels found in operating rooms at hospitals. Obsidian is also unique because each volcano produces obsidian that is chemically different - the obsidian from each volcano has a different "fingerprint" of chemical elements it contains. By matching the chemical fingerprint of the obsidian artifacts to the known chemical fingerprint of volcanic sources of obsidian, we can trace the artifacts to the volcanoes from where the obsidian raw material was originally obtained.
Two obsidian artifacts recovered from the Berezovka site on Iturup island.
Many obsidian flakes, and some obsidian tools, have been found at archaeological sites all across the Kuril Islands. But there are no sources of obsidian in the Kuril Islands themselves that were used by people living there in the past. This raises some interesting questions: Where did the obsidian originally come from? How was it transported to the Kuril Islands? Were different sources used in different places and at different points in time?
At the Smithsonian Institution Museum Conservation Institute laboratory, I am using a couple of high-tech methods to trace the obsidian artifacts to their volcanic sources in order to answer these questions. One method, called X-ray fluorescence (XRF), focuses X-rays on an obsidian artifact to generate energy that is read by a detector to determine the chemical fingerprint of that specific artifact. Another method, called Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICP-MS), uses a laser to vaporize a tiny amount of the obsidian artifact and generate elemental ions that are read by an instrument to tell us what the chemical fingerprint is.
The X-ray fluorescence instrument that Colby Phillips is using to analyze obsidian artifacts.
The results I have obtained so far show that the raw material used to make the obsidian artifacts we have found in the Kuril Islands originally came from volcanoes on the northern Japanese island of Hokkaido to the south, and from the Russian Kamchatka peninsula to the north. In some cases, the obsidian material was transported up to 1000 km (over 620 miles) from its source to the archaeological site where the KBP team found it. With this information, we can now start to think about how the past inhabitants of the Kuril Islands obtained the obsidian material they used to make stone tools. We can also consider what role obsidian trade or transport may have had in other parts of their lives, such as maintaining relationships with their neighbors or with relatives living on distant islands.
Map showing the sources of obsidian material used in the Kuril Islands.
So while the KBP archaeology team continues to gather information in the field, I will keep working in the lab to generate data that will help us build an explanation of how and from where people living in the Kuril Islands obtained the materials they needed to make tools for use in their everyday lives.
--Colby