In
archaeology
Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts ...
, a blade is a type of
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 ...
created by striking a long narrow
flake from a stone
core. This process of reducing the stone and producing the blades is called
lithic reduction
In archaeology, in particular of the Stone Age, lithic reduction is the process of fashioning stones or rocks from their natural state into tools or weapons by removing some parts. It has been intensely studied and many archaeological indust ...
. Archaeologists use this process of
flintknapping to analyze blades and observe their technological uses for historical purposes.
Blades are defined as being flakes that are at least twice as long as they are wide and that have parallel or subparallel sides and at least two ridges on the dorsal (outer) side. Blade cores appear and are different from regular flaking cores, as each core's
conchoidal
Conchoidal fracture describes the way that brittle materials break or fracture when they do not follow any natural planes of separation. Mindat.org defines conchoidal fracture as follows: "a fracture with smooth, curved surfaces, typically slig ...
nature is suited for different types of flaking. Blades are created using stones that have a
cryptocrystalline
Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert and flint are crypto ...
structure and easily be fractured into a smooth piece without fracturing. Blades became the favored technology of the
Upper Palaeolithic
The Upper Paleolithic (or Upper Palaeolithic) is the third and last subdivision of the Paleolithic or Old Stone Age. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories coi ...
era, although they are occasionally found in earlier periods. Different techniques are also required for blade creation; a soft punch or
hammerstone
In archaeology, a hammerstone is a hard cobble used to strike off lithic flakes from a lump of tool stone during the process of lithic reduction. The hammerstone is a rather universal stone tool which appeared early in most regions of the w ...
is necessary for creating a blade.
The long sharp edges of blades made them useful for a variety of purposes. After blades are flaked, they are often incorporated as parts of larger tools, such as
spear
A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with fire hardened spears, or it may be made of a more durable material fasten ...
s. Other times, the simple shape and sharpness serves the designed role. Blades were often employed in the impression process of material culture, assisting ancient humans in imprinting ornate designs into other parts of their material culture.
Scraper
Scrape, scraper or scraping may refer to:
Biology and medicine
* Abrasion (medical), a type of injury
* Scraper (biology), grazer-scraper, a water animal that feeds on stones and other substrates by grazing algae, microorganism and other matter
...
s, used for hide working or woodworking, or
burins, used for engraving, are two common such examples.
Cores from which blades have been struck are called blade cores and the tools created from single blades are called blade tools. Small examples (under 12 mm) are called
microblades and were used in the
Mesolithic
The Mesolithic (Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymo ...
as elements of composite tools. Blades with one edge blunted by removal of tiny flakes are called backed blade. A blade core becomes an exhausted core when there are no more useful angles to knock off blades.
Blades can be classified into many different types depending on their shape and size. Archaeologists have also been known to use the microscopic striations created from the lithic reduction process to classify the blades into specific types. Once classified archaeologists can use this information to see how the blade was produced, who produced it, and how it was used.
Cultural implications
Blade technology, too, is able to provide researchers with understanding of the social realms of the culture in question. For example, in 2002 an article was published concerning research done in Tehran, Iran. The research focused on six late prehistoric sites which coincidentally had a large focus of blade production.
The main focus of the paper concentrated on the early
Chalcolithic
The Copper Age, also called the Chalcolithic (; from grc-gre, χαλκός ''khalkós'', " copper" and ''líthos'', " stone") or (A)eneolithic (from Latin ''aeneus'' "of copper"), is an archaeological period characterized by regul ...
and showed that as time passed and the
chopper tools became more prominent, stone tools became less aesthetically pleasing. Thus, there was a collapse of lithic craft specialization. Wherein raw material was being sent out and coming back in as blades, people were producing their own blades at home.
[ The raw materials that these tools were made of were also very diverse. 92% of the Chalcolithic tool variety was a product of ]chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a ...
, a sedimentary rock indigenous to the area and easily harvested. Other raw materials found in the collection, such as obsidian, suggested that trading and expeditions were sources for blade cores, too, as these raw materials were not readily available.[ The provenance of parts of a culture's material culture illuminates common trade patterns and needs of that society for archaeologists. If the resources are not available, how they traded these raw materials such as obsidian to improve their blades and stone tool technology.
Likewise, the blades and blade cores located in the Ambergris Caye Museum dated to Mayan inhabitation showed heavy reliance on obsidian. Because obsidian is not natural to Belize, the site of excavation, the obsidian cores were the product of transactions between the Mayans and those in present-day Honduras, Mexico and Guatemala. Obsidian blades are the sharpest natural cutting edges known, and after the lithic reduction already fractured blades, the triangular heads were produced. These obsidian blades were used as the Mayans' primary cutting utensil.]
See also
* Prismatic blade
*Lithic technology
In archaeology, lithic technology includes a broad array of techniques used to produce usable tools from various types of stone. The earliest stone tools were recovered from modern Ethiopia and were dated to between two-million and three-million ...
Further reading
*Butler, C (2005). ''Prehistoric Flintwork'', Tempus, Stroud. .
*Darvill, T (ed.) (2003). ''Oxford Concise Dictionary of Archaeology'', Oxford: Oxford University Press. .
References
{{Prehistoric technology, state=expanded
Lithics
Archaeological artefact types