What is “chert”?
The most prevalent type of artifact found on a prehistoric site is a chert flake. Chert is a crude type of siliceous rock (a form of flint), which was the primary raw material used by the aboriginal inhabitants of Fort Drum for the manufacture of a wide variety of tools including projectile points (spear and arrowheads), drills, knives and scrapers. Chert occurs naturally under specific geological conditions in bedrock formations, where it can be “mined” or extracted in chunks or nodules. Chert nodules were hammered and flaked into the rough outline of a “biface” or preform, and then finely flaked into a finished tool such as an arrowhead. In the process of making a biface or a finished tool, hundreds of small waste flakes are removed and discarded. Archeologists frequently find a scatter of these chert flakes (debitage), an important clue towards documenting a site. These flakes themselves sometimes have razor-sharp edges, which were simply an expedient tool for cutting or scraping, s
The most prevalent type of artifact found on a prehistoric site is a chert flake. Chert is a coarse type of siliceous rock (a form of flint or chalcedony), which was the primary raw material used by the aboriginal inhabitants of southern Ontario for the manufacture of a wide variety of tools including projectile points (spear and arrowheads), drills, knives and scrapers. Chert occurs naturally under specific geological conditions in bedrock formations, where it can be “mined” or extracted in chunks or nodules. But glaciation wreaked havoc on the landscape, and nodules of various types of chert were distributed as glacial outwash and in moraines throughout southern Ontario. For example, nodules of Onondaga chert which originates in veins in the Onondaga Escarpment in the Fort Erie to Port Colbourne area of the Niagara Peninsula can be found today on the surface of fields around London. Chert nodules were hammered and flaked into the rough outline of a “biface” or preform, and then finel
