Edziza obsidian is a naturally formed

volcanic glass Volcanic glass is the amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disordered array of liqu ...

found at the Mount Edziza volcanic complex in northwestern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, Canada. It occurs in at least four

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

s of the volcanic complex and was widely used by

indigenous peoples Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...

during the

pre-Columbian era In the history of the Americas, the pre-Columbian era spans from the Migration to the New World, original settlement of North and South America in the Upper Paleolithic period through European colonization of the Americas, European colonization, w ...

. As a result of its widespread use, Edziza

obsidian Obsidian () is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements s ...

has been found in several

archaeological site An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology an ...

s throughout the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

Sources

Edziza obsidian occurs as lava flows at various elevations throughout the northern and southern ends of the Mount Edziza volcanic complex. The largest occurrence of Edziza obsidian is centred on Goat Mountain in the

Spectrum Range The Spectrum Range, formerly called the Spectrum Mountains and the Rainbow Mountains, is a subrange of the Tahltan Highland in the Stikine Country of northwestern British Columbia, 20 km west of the Stewart-Cassiar Highway, south of Mount ...

where it is associated with the Spectrum Formation. Edziza obsidian associated with the Armadillo Formation occurs at

Artifact Creek Artifact Creek is a tributary of Stewbomb Creek and part of the Stikine River watershed in northwest part of the province of British Columbia, Canada. It flows generally southeast for roughly Lengths and distances measured using BCGNIS coordinat ...

, Fan Creek,

Coffee Crater Coffee Crater is a well-preserved cinder cone south of Mount Edziza, British Columbia, Canada. It was formed during the Holocene period. It is within the Snowshoe lava field, part of the Mount Edziza volcanic complex. See also *List of volcano ...

, Destell Pass and Cartoona Peak. The obsidian also occurs on The Pyramid, a

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...

of the Pyramid Formation. Sorcery Ridge of the Ice Peak Formation also contains Edziza obsidian.

Distribution

Edziza obsidian is the most widely distributed obsidian in western North America and perhaps the most widely distributed obsidian in subarctic North America, occurring over an area of more than . It has been recovered from archaeological sites in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...

, western

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

and along the

British Columbia Coast , settlement_type = Region of British Columbia , image_skyline = , nickname = "The Coast" , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 = British ...

, having been used by North American indigenous peoples to make

stone tool A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric (particularly Stone Ag ...

s as early as 10,000 years ago. The obsidian was especially used for thousands of years by the

Tahltan The Tahltan or Nahani are a First Nations people of the Athabaskan-speaking ethnolinguistic group who live in northern British Columbia around Telegraph Creek, Dease Lake, and Iskut. The Tahltan constitute the fourth division of the ''Nahane' ...

people who live adjacent to the Mount Edziza volcanic complex. In Alaska, Edziza obsidian has been recovered from the 10,300-year soil layer level of the

On Your Knees Cave On Your Knees Cave (49-PET-408) is an archaeological site located in southeastern Alaska ( Prince of Wales Island). Human remains were found at the site in 1996 that dated between 9,730 ±60 and 9,880±50 radiocarbon YBP (Years Before Present) or ...

archaeological site on Prince of Wales Island. A 4,100-year-old Tlingit village site near Coffman Cove dubbed 49-PET-067 also contains Edziza obsidian. In Alberta, flakes of Edziza obsidian have been found at Patricia Lake near the town of

Jasper Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref> ...

. In British Columbia, two fragments of Edziza obsidian have been recovered from the Bluejackets Creek archaeological site on Haida Gwaii and are presumably of late

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

age.

References

External links

*{{cite thesis, last1=Godfrey-Smith, first1=Dorothy I., url=https://www.deschutesmeridian.com/IAOS/pdf/godfrey-smith_1985.pdf, title=X-Ray Fluorescence Characterization of the Obsidian Flows from the Mount Edziza Volcanic Complex, British Columbia, Canada, year=1985, type=

Master's degree A master's degree (from Latin ) is an academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional practice.

Mount Edziza volcanic complex Obsidian Tahltan Tlingit Archaeology of British Columbia Archaeology of Alberta Archaeology of Yukon Archaeology of the United States Pre-Columbian archaeology