Dig It is KTW’s regularly published column on the history beneath our feet in the Kamloops region. A group of nine professional archeologists living and working in the area contribute columns to this page and online at kamloopsthisweek.com twice per month. To read previous columns, search “Dig It” on our website.
Obsidian, a naturally occurring volcanic glass, was highly valued by people living in the southern Interior in years past.
Even today, mineral enthusiasts value obsidian for its aesthetic qualities.
When manufactured into stone tools, the edges are razor sharp (obsidian blades are still used in certain surgical applications because they are much sharper than surgical steel).
Obsidian tools are rare in archological sites in the Kamloops region. When they are found, they are usually heavily re-used and re-sharpened, having been well cared for by their owners.
While further research may reveal a local source of obsidian in the southern Interior, archeologists have not identified a local source for this highly valued material. The nearest sources, or quarries, hundreds of kilometres away: Glass Butte in southeastern Oregon; Bear Gulch in Yellowstone National Park, Idaho; two sources at Itcha Ilgachuz and Obsidian Creek in Tsilhqot’in territory, west of Williams Lake; Mount Garibaldi near Squamish; and Mount Edziza in Tahltan territory in northwestern B.C.
Not surprisingly, archeological sites near these source quarries often contain large quantities of obsidian artifacts.
It appears to have been highly valued by many cultural groups, however, because small numbers of obsidian artifacts can be found almost anywhere in B.C.
When found in archeological sites, obsidian can provide archeologists with important clues about ancient trade routes and exchange networks.
The source quarries of obsidian artifacts can be determined using an analysis technique called X-ray fluorescence.
Because obsidian is formed from the cooled lava flows of ancient volcanic eruptions, each obsidian source contains a unique chemical signature, which can be measured using this technique.
X-ray fluorescence is fast and inexpensive and has become a popular tool for archeologists in B.C. and elsewhere to gain a little more insight into how people lived.
Obsidian from the Idaho and Oregon and the Edziza and Obsidian creek localities, as well as from sources further afield, have been recovered in the southern Interior of this province.
Obsidian has been recovered from sites dating as far back as some of the earliest recorded sites in the Kamloops area and as recently as the 19th century.
This tells us established long-distance regional trade networks with other cultural groups must have existed several thousand years ago and that obsidian remained a highly traded resource for a long period of time.
While much more research into ancient trade networks is needed, many archeologists, myself included, love to speculate about uncommon or rare artifacts found during an archeological study.
Obsidian was likely mined in surplus by the cultural groups who had the rights to the quarries and traded to neighbouring communities for various goods, such as jade, dentalium shell, food items, copper, basketry, and other “exotic” materials.
Obsidian appears to have been traded into the Kamloops area from the Columbia Plateau to the south and from the northern Interior (and, possibly, from the B.C. Coast).
It is probable that obsidian traded hands several times before arriving in the Kamloops area, gaining value with every exchange.
By the time it arrived in the local area, it had travelled hundreds of kilometres and is possible only wealthier families could afford to trade for it.
While the practical uses for obsidian are obvious, it is possible it was also a symbol of wealth for those who had tools made from it.
Ramsay McKee is a Kamloops-based archeologist.
Interested in more? Go online to republicofarchaeology.ca.