Debitage is all the material produced during the process of lithic reduction and the production of chipped stone tools. This assemblage includes, but is not limited to, different kinds of lithic flakes and lithic blades, shatter and production debris, and production rejects.

GLAM Ice Age 125
Example of lithic refitting
Flints Sturge collection Caddington pit C
Series of refitted debris

Debitage analysis

Debitage analysis, a sub-field of lithic analysis, considers the entire lithic waste assemblage. The analysis is undertaken by investigating differing patterns of debris morphology, size, and shape, among other things. This allows researchers to make more accurate assumptions regarding the purpose of the lithic reduction. Quarrying activities, core reduction, biface creation, tool manufacture, and retooling are believed to leave significantly different debitage assemblages. Lithic manufacture from a quarried source, or from found cobbles also leave different signatures. Some claim that they can determine the sort of tools used to create the debitage. Others feel it is possible to effectively estimate the work-hours represented, or the skill of the workers based on the nature of the debitage.

Debitage analysis of biface reduction can be used to determine what stage of reduction is represented in waste. Stahle and Dunn (1982) found that, as waste flake size decrease from initial to final stages in biface production, systematic changes in flake size can be used to identify stages of reduction in anonymous debitage samples through comparison with experimental assemblages. Use of Weibull distributions and least square analysis helped Stahle and Dunn confirm that this method can be used backward to estimate reduction stages of particular debitage frequencies.[1] Other studies comparing the debitage of bifacial reduction during different stages has not yielded such positive results. Patterson (1990) was unable to distinguish between the stages of initial edging and secondary thinning using statistical analysis of 14 experimental assemblages.[2]

The typological approach groups together lithics with similar manufacturing histories in order to emphasize patterns of manufacturing behavior (as in Sheets 1975).[3] To use Sheets’ (1983:200) example, macroblades and prismatic blades were separated on the basis of their manufacture, in that the former was removed by percussion, while the latter was removed by a pressure technique. Casual, informal tools from unstandardized cores should be given scrutiny equal to that of formal tools from standardized core reduction.

The presence of cortex needs to be noted for all tool categories in all materials. The presence of cortex indicates the importation of an unworked nodule, with the first flakes both preparing the core by shaping and removing the roughened exterior of the cortex (Sheets 1978:9). The percentage frequency of cortex is an important statistic to help identify lithic production areas. A low incidence of cortex would indicate quarry preforming (cortex removed at the quarry, not at the site).

One specific type of debitage analysis is mass analysis. Mass analysis is based on analyzing debitage populations based on their size distribution across specified size grades. Ahler (1989) conducted an experimental replication under some technological settings and classified debitage into five groups according to their size, Discriminant analysis (by SPSS DISCRIMINANT function) was applied to compare mass analysis data sets for these five experimental data groups. He then compared the counts and weights of experimental samples with debris from two prehistoric workshop sites in western North Dakota. The result shows the experimental data sets can explain the technological composition of archaeological samples. Samples from several other sites also are applied this method and derive clear discriminant results. Especially in a specific function site, such as Legacy site a Late Woodland age camp in the Missouri breaks, associated with bison kill/butchering, the low frequency of cortex and a specific flake ratio (G4:Gl-3 ) data indicate that a soft hammer small flake tool production, which is similar with experiment result.[4] Although this process has been used in many studies, Andrefsky warns of the potential problems associated with the many assumptions made while employing this analysis. One in particular that he draws attention to is the possibility of differences in debitage populations based on individual variation of the artifact maker; in his example, three different knappers all using bipolar core reduction have different percentages of size grade 3 debitage (5.2%, 13.2%, and 10.2%). These differences indicate that individual variation can be influential in the size distribution of debitage and should be kept in mind if mass analysis is being employed.[5] The reason for which Andrefsky believes mass analysis have become so popular is due to the process's ease of use and speed.[6] Andrefsky even quotes Ahler[7] that between individual specimen analysis and mass analysis, mass analysis has the advantage because of four reasons: 1) biases are eliminated because mass analysis looks at the entire assemblage; both completed and fractured. 2) Because mass analysis doesn't require looking at each artifact, it is very rapid and efficient. 3) debitage biases based on the sample's size are reduced since it merely captures different specimen sizes. 4) the method is highly objective and can be trained by virtually anyone.[8]

In addition, various attributes can be used for statistical and numerical methods which are currently used for debitage analysis. The attributes divides in the two ways, metric and non-metric. In the metric attributes, length, mid width, max width, platform length, platform width, bulb thickness, other point of thickness, platform angle and weight are included. And for the non-metric attributes, platform configuration, platform facet count, % dorsal cortex, dorsal scar count, remained portion, and size grade can be chosen.[9] Bradbury and Carr specifically point to the continuum model to analyze flakes and these listed variables to try to determine which flake debris were caused by different actions (core reduction, tool making, etc.) [10][11]

Sullivan and Rozen (1985) introduced a method of classifying debitage into four categories: complete flakes, broken (proximal) flakes, flake fragments (medial-distal flakes), and fragments that are unable to be oriented.[12] Some success has been shown in using this classification to differentiate between different reduction strategies. Using discriminant analysis and Sullivan and Rozen's system to classify debitage, Austin (1997) was able to correctly distinguish between patterned tool and core reduction techniques for 93.33% of his experimental assemblages.[13] Austin also tested how this typology would operate with mixed assemblages. He found that in an assemblage where there is a mixture of debitage from a patterned tool and core reduction, it is likely to be classified as a patterned tool assemblage, if the core debitage represents 50% or less of the total assemblage.[14] Austin pointed out many factors that could change the characteristics of debitage (post-depositional processes, differences in raw material, etc.) and suggested that his method should be used in a preliminary fashion.


Debitage refitting is a process whereby the collected assemblages of debitage are painstakingly put back together, like pieces in a puzzle. This can sometimes indicate the nature of the tools being produced, although missing pieces are a significant problem. More often, debitage refitting is used to learn how rocks were moved during the lithic manufacture process. This can sometimes indicate work areas, division of labor, or trade routes.


Debitage sourcing looks at the physical properties of the worked stone in an attempt to determine where on the earth it was obtained. This may require sophisticated equipment, and destructive testing, but even a visual inspection can provide a general idea. Sourcing is assumed to provide information about trade, or travel routes.


Some debitage material has been examined in an effort to obtain dates. Since debitage is plentiful, and individual specimens are usually not diagnostic, they can often undergo destructive analysis that would not be suitable for other artifacts. Results have been promising, but not spectacular. Obsidian and cryptocrystalline silicates appear to be the most promising materials for destructive analysis.

Obsidian, as a natural glass material, is peculiar because when it is exposed to water, the surface develops a patinated layer of hydrated perlite. Old fractures therefore have thicker layers of patina than more recent flake scars. As the rate of hydration is determined by factors such as moisture content, temperature, and the chemical composition of the obsidian, this method cannot provide absolute dates. However, this method has the major advantage of relying on obsidian flaking as the activating cause in this dating scheme.

Cryptocrystalline silicates, such as flint and chert, are sometimes heat-treated in order to improve the flaking properties of the material. This heating can be used as a zeroing point, and the date since the material was last heated can be established through fission track counts, thermoluminescence, or, in some rare cases, paleomagnetism. These provide absolute dates. Unfortunately, not all such tool stones were heat-treated, and not all heat-treatment is due to human agency. Forest fires are one way that stones can be heat-treated without human action.

See also


  1. ^ Stahle., D; Dunn J., J (1982). "An analysis and application of the size distribution of waste flakes from the manufacture of bifacial stone tools". World Archaeology. 14: 84–97. doi:10.1080/00438243.1982.9979851.
  2. ^ Patterson, L (1982). "Characteristics of Bifacial-Reduction Flake-Size Distribution". American Antiquity. 55: 550–558.
  3. ^ Sheets, Payson D.; Anthony, B. W.; Breternitz, David A.; Brose, David S.; et al. (1975). "Behavioral Analysis and the Structure of a Prehistoric Industry". Current Anthropology. 16 (3): 369–391. doi:10.1086/201569.
  4. ^ Ahler, S.A. 1989 Mass analysis of flaking debris: studying the forest rather than the trees. In D.O. Henry and G.H. Odell (eds). Alternative Approaches to Lithic Analysis. Pp.85-118. Archeological Papers of the American Anthropological Association
  5. ^ Andrefsky Jr., William (2007). "The application and misapplication of mass analysis in lithic debitage studies". Journal of Archaeological Science. 34 (3): 392–402. doi:10.1016/j.jas.2006.05.012.
  6. ^ Andrefsky Jr., William (2007). "The application and misapplication of mass analysis in lithic debitage studies". Journal of Archaeological Science. 34: 392–402. doi:10.1016/j.jas.2006.05.012. Retrieved 19 November 2014.
  7. ^ Ahler, Stanley (1989). "Mass analysis of flaking debris: studying the forest rather than the trees". Archeological Papers of the American Anthropological Association: 85–118.
  8. ^ Andrefsky Jr., William (2007). "The application and misapplication of mass analysis in lithic debitage studies". Journal of Archaeological Science. 34: 392–402. doi:10.1016/j.jas.2006.05.012. Retrieved 19 November 2014.
  9. ^ Andrew P., Bradbury; Philip J., Carr (1999). "Examining Stage and Countinuum Models of Flake Debris Analysis: An Experimental Approach". Journal of Archaeological Science. 26: 105–116. doi:10.1006/jasc.1998.0309.
  10. ^ Andrew P., Bradbury; Philip J., Carr (1999). "Examining Stage and Countinuum Models of Flake Debris Analysis: An Experimental Approach". Journal of Archaeological Science. 26: 105–116. doi:10.1006/jasc.1998.0309.
  11. ^ Bradbury, Andrew; Carr, Philip (2014). "Non-Metric Continuum-Based Flake Analysis". Lithic Technology. 39 (1): 20–38. doi:10.1179/0197726113z.00000000030.
  12. ^ Sullivan, Alan P.; Rozen, Kenneth C. (1985). "Debitage analysis and archaeological interpretation". American Antiquity. 50 (4): 755–779. doi:10.2307/280165.
  13. ^ Austin, Robert J. (1997). "Technological characterization of lithic waste-flake assemblages: multivariate analysis of experimental and archaeological data". Lithic Technology. 24 (1): 53–68.
  14. ^ Austin, Robert J. (1999). "Technological characterization of lithic waste-flake assemblages: multivariate analysis of experimental and archaeological data". Lithic Technology. 24 (1): 53–68.
Altar Stone (Stonehenge)

The Altar Stone is a recumbent central megalith at Stonehenge in England, dating to Stonehenge phase 3i, around 2600 BC. It is made of a purplish-green micaceous sandstone and is thought to have originated from outcrops of the Senni Beds formation of the Old Red Sandstone in Wales, though this is currently in debate. Stone 80 (Altar Stone) was most recently excavated in the 1950s, but no written records of the excavation survive, and there are no samples available for examination that are established as having come from the monolith. Stone 55 (a sarsen megalith) lies on top of Stone 80 perpendicularly, and is thought to have fallen across it. The Altar Stone weighs approximately six tons and (if it ever was upright) would have stood nearly two metres tall. Some believe that it always was recumbent It is sometimes classed as a bluestone, because it does not have a local provenance.

Its name probably comes from a comment by Inigo Jones who wrote: "...whether it might be an Altar or no I leave to the judgment of others’.


Cacaopera is a municipality in the Morazán department of El Salvador.

According to UNESCO:

The community of Cacaopera is the sole surviving representative of an otherwise vanished ethnic group, variously referred to as Ulua, Matagalpa, or Cacaopera. Linguistic evidence suggests that this group originated in lower Central America, and at some point in time (but shortly before the conquest) established an enclave within the territory of eastern El Salvador. Some of the traits which continue to identify members of the community with this ethnic group are architecture, subsistence patterns, religious practices, myths, legends, and clothing styles. The marked traditionalism of Cacaopera can be attributed, in part, to its isolation within the very mountainous terrain of northern Morazan department. This region was severely affected by the war. Many of the inhabitants of outlying hamlets relocated to Cacaopera. Cacaopera was alternatively occupied by Army and FMLN troops, and was the scene of firefights and bombardments. These circumstances has introduced considerable changes in traditional lifeways. Several archaeological sites have been recorded within the Cacaopera municipality. Tradition identifies some of these as former locations of Ulua communities. Other sites are definitely of much greater antiquity, probably reaching far back into the Archaic Period. A number of sites consist of rock shelters with petroglyphs, pictographs, and lithic flakes and debitage.

Creswellian culture

The Creswellian is a British Upper Palaeolithic culture named after the type site of Creswell Crags in Derbyshire by Dorothy Garrod in 1926. It is also known as the British Late Magdalenian. The Creswellian is dated between 13,000–11,800 BP and was followed by the most recent ice age, the Younger Dryas, when Britain was at times unoccupied by humans.

Cumberland point

A Cumberland point is a lithic projectile point, attached to a spear and used as a hunting tool. These sturdy points were intended for use as thrusting weapons and employed by various mid-Paleo-Indians (c. 11,000 BP) in the Southeastern US in the killing of large game mammals.


Douwara is a Heavy Neolithic archaeological site of the Qaraoun culture located 2 kilometres (1.2 mi) southwest of Ain Ebel in the Bint Jbeil District of Nabatieh Governorate in Lebanon. It is located on slopes north of the road from Ain Ebel to Rmaich.It was discovered by Jesuit priest Henri Fleisch, whilst out prospecting for prehistoric sites in 1950, who published his findings in 1951 and 1954. The collections from the site were also discussed by Jacques Cauvin. Vast numbers of heavy tools were found representing the industry of the Qaroun culture including piles of debitage and bifaces. Another industry present at the site was tentatively identified as Chalcolithic and included axes, chisels and heavy borers that resembled Minet ed Dhalia points.


A geofact (a portmanteau of "geology" and "artifact") is a natural stone formation that is difficult to distinguish from a man-made artifact. Geofacts could be fluvially reworked and be misinterpreted as an artifact, especially when compared to paleolithic artifacts.Some of the proposed criteria for distinguishing geofacts from artifacts for paleolithic specimens resembling debitage have been subjected to evaluation by experimental and actualistic studies. If the artifact has two or more of the following, then the artifact is more than likely to be a geofact.

Distinguishing geofacts from lithic debitage, through experiments and comparisons:Possible examples include several purported prominent ancient artifacts, such as the Venus of Berekhat Ram and the Venus of Tan-Tan. These are thought by many in the archaeological community to be geofacts. A site which shows an abundance of what are likely geofacts is the Gulf of Cambay.

Geofacts versus artifacts or as British scientists refer “artefacts” are just one of the battles archaeologists go through while excavating a site. In the article, “Artefact-Geofact Analysis of The Lithic Material from The Susiluola Cave,” by Hans-Peter Schulz (2007) whom explained Geofacts are multi-shaped rocks that can be found while archaeologists are trying to find true artifacts during past glacial periods. Glacial periods such as the Eemian interglacial and the Middle Weichselian glaciation located in the northern parts of the world melted and began to move rocks from their original areas while they scraped everything around them. The rock movement created sometimes weapon like spears from smaller rocks and appear as artifacts but instead are just a product of glacial melting. Another element Schulz explained is the mixing of natural and salt water during the glaciations, which changed sediment locations within rocks such as the Susiluola cave located in Finland. Once the ice melted the sediment and ice created some artificial markings on pebble sized rocks. Some elements that could morph rock shapes in caves include sandstone, siltstone and quartzite creating a kinetic process of shaping the rocks. There are measurements Schulz created to distinguish a geofact such as blow angles from a sandstone or quartzite rock with a limit between 45 and 90 degrees, and if the abrasions were rounded these are considered geofacts.Artifacts are interpreted as geofacts so often that they have entire articles filled with correcting excavations. Archeological geologist Paul V. Henrich (2002) corrects journalist Graham Hancock in article, “Artifacts or Geofacts? Alternative Interpretations of Items from the Gulf of Cambay” of his alleged artifacts found in the Gulf of Cambay, India is geofacts. Henrich illustrates in pictures that these designed artifacts were a combination of cement, layered coarse and fine laminated sand stacked tightly together from lamented lake silts with enough porosity appearing rigid to look like a human design. Other corrections Henrich made were Hancock’s “Cambay pendants” large flat rock objects with a hole in between assumed as jewelry but are naturally formed holes created by marine organisms. Henrich claims during excavations the team should have a geologist on site because they are experts in rock formations to help distinguish between an artifact and geofact.Artifacts mixed with human remains can certainly contain mixtures of Geofacts. In the article, “The alleged Early Paleolithic artefacts are in reality geofacts: a revision of the site of Konczyce Weilkie 4 in the Moravian Gate, South Poland,” Wiśniewski et. all. (2014), explain when geofacts are mixed with artifacts in a fluvial gravel pit it becomes very difficult to distinguish between the two. Another issue Wisniewski questioned is if the site was livable during the Paleolithic period because artifacts are mobile and therefore would not be found in situ however, rocks that are native to the area would usually be a geofact. A helpful hint to decide if an item is an artifact or geofact is if there are multiple rocks that have similar edges and shapes and this type of rock is in its natural environment then it is most likely a geofact. An argument the previous excavators claimed was that some rocks were found over 140 meters from their original environment meaning they could have been artifacts moved by humans. However this was quickly refuted because evidence in glacial moraines and fluvial-glacial deposits caused many rocks to move a similar distance from their original environment. Clearly distinguishing geofacts from artifacts is not a simple task however, if excavators stick with the proper requirements and assumptions there will be far less misinterpretations in the future.

Grinding slab

In archaeology, a grinding slab is a ground stone artifact generally used to grind plant materials into usable size, though some slabs were used to shape other ground stone artifacts. Some grinding stones are portable; others are not and, in fact, may be part of a stone outcropping.

Grinding slabs used for plant processing typically acted as a coarse surface against which plant materials were ground using a portable hand stone, or mano ("hand" in Spanish). Variant grinding slabs are referred to as metates or querns, and have a ground-out bowl. Like all ground stone artifacts, grinding slabs are made of large-grained materials such as granite, basalt, or similar tool stones.


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 world including Europe, India and North America. This technology was of major importance to prehistoric cultures before the age of metalworking.

Industry (archaeology)

In the archaeology of the Stone Age, an industry or technocomplex is a typological classification of stone tools. It is not to be confused with industrial archaeology, which concentrates on industrial sites from more recent periods.

An industry consists of a number of lithic assemblages, typically including a range of different types of tools, that are grouped together on the basis of shared technological or morphological characteristics. For example, the Acheulean industry includes hand-axes, cleavers, scrapers and other tools with different forms, but which were all manufactured by the symmetrical reduction of a bifacial core producing large flakes. Industries are usually named after a type site where these characteristics were first observed (e.g. the Mousterian industry is named after the site of Le Moustier). By contrast, Neolithic axeheads from the Langdale axe industry were recognised as a type well before the centre at Great Langdale was identified by finds of debitage and other remains of the production, and confirmed by petrography (geological analysis). The stone was quarried and rough axe heads were produced there, to be more finely worked and polished elsewhere.

As a taxonomic classification of artefacts, industries rank higher than archaeological cultures. Cultures are usually defined from a range of different artefact types and are thought to be related to a distinct cultural tradition. By contrast, industries are defined by basic elements of lithic production which may have been used by many unrelated human groups over tens or even hundred thousands of years, and over very wide geographical ranges. Sites producing tools from the Acheulean industry stretch from France to China, as well as Africa. Consequently, shifts between lithic industries are thought to reflect major milestones in human evolution, such as changes in cognitive ability or even the replacement of one human species by another. Therefore, artefacts from a single industry may come from a number of different cultures.

La Grange Rock Shelter

The LaGrange Rock Shelter is an archaeological site located on private property between Leighton and Muscle Shoals in Colbert County, Alabama near the original campus of LaGrange College. The shelter measures 70 feet long by 15 feet deep (21m by 4.5m) and is located beneath a sandstone outcrop overlooking a dense series of Paleoindian sites in the valley below, which may have led to it being chosen for excavation.Excavations of the site occurred over two seasons, beginning in 1972 with Charles Hubbert as principal investigator and ending in 1975 with Vernon J. Knight Jr as principal investigator, with both seasons under the direction of David L. DeJarnette of the University of Alabama. Lower levels of the shelter produced charcoal samples that were radiocarbon dated to approximately 11,280 BC, placing estimates of the site's habitation within what is believed to be the Paleoindian Period. At the time of the discovery, only one other site east of the Mississippi River had been dated to that age.The charcoal consisted of small flecks associated with light debitage below a definitive Early Archaic to Late Paleoindian (Dalton culture) zone. After careful consideration, DeJarnette and Knight suggested that the charcoal originated from an upper level and migrated to the lower level due to breakdown of the original shelter floor. Although the Paleoindian date may be questioned, the site also contained a remarkable Early Archaic burial, one of the oldest burials uncovered in the State of Alabama.The site was listed on the National Register of Historic Places in 1974.

Langdale axe industry

The Langdale axe industry is the name given by archaeologists to specialised stone tool manufacturing centred at Great Langdale in England's Lake District during the Neolithic period (beginning about 4000 BC in Britain). The existence of a production site was originally suggested by chance discoveries in the 1930s, which were followed by more systematic searching in the 1940s and 1950s by Clare Fell and others. The finds were mainly reject axes, rough-outs and blades created by knapping large lumps of the rock found in the scree or perhaps by simple quarrying or opencast mining. Hammerstones have also been found in the scree and other lithic debitage from the industry such as blades and flakes.

The area has outcrops of fine-grained greenstone or hornstone suitable for making polished stone axes. Such axes have been found distributed across Great Britain. The rock is an epidotised greenstone quarried or perhaps just collected from the scree slopes in the Langdale Valley on Harrison Stickle and Pike of Stickle. The nature and extent of the axe-flaking sites making up the Langdale Axe Factory complex are still under investigation.

Geological mapping has established that the volcanic tuff used for the axes outcrops along a narrow range of the highest peaks in the locality. Other outcrops in the area are known to have been worked, especially on Harrison Stickle, and Scafell Pike where rough-outs and flakes have been found on platforms below the peaks at and above the 2000- or 3000-foot level.

Levallois technique

The Levallois technique (IPA: [lə.va.lwa]) is a name given by archaeologists to a distinctive type of stone knapping developed by precursors to modern humans during the Palaeolithic period.

It is named after nineteenth-century finds of flint tools in the Levallois-Perret suburb of Paris, France. The technique was more sophisticated than earlier methods of lithic reduction, involving the striking of lithic flakes from a prepared lithic core. A striking platform is formed at one end and then the core's edges are trimmed by flaking off pieces around the outline of the intended lithic flake. This creates a domed shape on the side of the core, known as a tortoise core, as the various scars and rounded form are reminiscent of a tortoise's shell. When the striking platform is finally hit, a lithic flake separates from the lithic core with a distinctive plano-convex profile and with all of its edges sharpened by the earlier trimming work.

This method provides much greater control over the size and shape of the final flake which would then be employed as a scraper or knife although the technique could also be adapted to produce projectile points known as Levallois points. Scientists consider the Levallois complex to be a Mode 3 technology, as a result of its diachronic variability. This is one level superior to the Acheulean complex of the Lower Paleolithic.

Lithic analysis

In archaeology, lithic analysis is the analysis of stone tools and other chipped stone artifacts using basic scientific techniques. At its most basic level, lithic analyses involve an analysis of the artifact’s morphology, the measurement of various physical attributes, and examining other visible features (such as noting the presence or absence of cortex, for example).

The term 'lithic analysis' can technically refer to the study of any anthropogenic (human-created) stone, but in its usual sense it is applied to archaeological material that was produced through lithic reduction (knapping) or ground stone. A thorough understanding of the lithic reduction and ground stone processes, in combination with the use of statistics, can allow the analyst to draw conclusions concerning the type of lithic manufacturing techniques used at a prehistoric archaeological site. For example, they can make certain equation between each the factors of flake to predict original shape. These data can then be used to draw an understanding of socioeconomic and cultural organization.

The term knapped is synonymous with "chipped" or "struck", but is preferred by some analysts because it signifies intentionality and process. Ground stone generally refers to any tool made by a combination of flaking, pecking, pounding, grinding, drilling, and incising, and includes things such as mortars/metates, pestles (or manos), grinding slabs, hammerstones, grooved and perforated stones, axes, etc., which appear in all human cultures in some form. Among the tool types analyzed are projectile points, bifaces, unifaces, ground stone artifacts, and lithic reduction by-products (debitage) such as flakes and cores.

Lithic flake

In archaeology, a lithic flake is a "portion of rock removed from an objective piece by percussion or pressure," and may also be referred to as a chip or spall, or collectively as debitage. The objective piece, or the rock being reduced by the removal of flakes, is known as a core. Once the proper tool stone has been selected, a percussor or pressure flaker (e.g., an antler tine) is used to direct a sharp blow, or apply sufficient force, respectively, to the surface of the stone, often on the edge of the piece. The energy of this blow propagates through the material, often (but not always) producing a Hertzian cone of force which causes the rock to fracture in a controllable fashion. Since cores are often struck on an edge with a suitable angle (x<90°) for flake propagation, the result is that only a portion of the Hertzian cone is created. The process continues as the flintknapper detaches the desired number of flakes from the core, which is marked with the negative scars of these removals. The surface area of the core which received the blows necessary for detaching the flakes is referred to as the striking platform.

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 industries are identified almost entirely by the lithic analysis of the precise style of their tools and the chaîne opératoire of the reduction techniques they used.

Normally the starting point is the selection of a piece of tool stone that has been detached by natural geological processes, and is an appropriate size and shape. In some cases solid rock or larger boulders may be quarried and broken into suitable smaller pieces, and in others the starting point may be a piece of the debitage, a flake removed from a previous operation to make a larger tool. The selected piece is called the lithic core (also known as the "objective piece"). A basic distinction is that between flaked or chipped stone, the main subject here, and ground stone objects made by grinding. Flaked stone reduction involves the use of a hard hammer percussor, such as a hammerstone, a soft hammer fabricator (made of wood, bone or antler), or a wood or antler punch to detach lithic flakes from the lithic core. As flakes are detached in sequence, the original mass of stone is reduced; hence the term for this process. Lithic reduction may be performed in order to obtain sharp flakes, of which a variety of tools can be made, or to rough out a blank for later refinement into a projectile point, knife, or other object. Flakes of regular size that are at least twice as long as they are broad are called blades. Lithic tools produced this way may be bifacial (exhibiting flaking on both sides) or unifacial (exhibiting flaking on one side only).

Cryptocrystalline or amorphous stone such as chert, flint, obsidian, and chalcedony, as well as other fine-grained stone material, such as rhyolite, felsite, and quartzite, were used as a source material for producing stone tools. As these materials lack natural planes of separation, conchoidal fractures occur when they are struck with sufficient force; for these stones this process is called knapping. The propagation of force through the material takes the form of a Hertzian cone that originates from the point of impact and results in the separation of material from the objective piece, usually in the form of a partial cone, commonly known as a lithic flake. This process is predictable, and allows the flintknapper to control and direct the application of force so as to shape the material being worked. Controlled experiments may be performed using glass cores and consistent applied force in order to determine how varying factors affect core reduction.It has been shown that stages in the lithic reduction sequence may be misleading and that a better way to assess the data is by looking at it as a continuum. The assumptions that archaeologists sometimes make regarding the reduction sequence based on the placement of a flake into a stage can be unfounded. For example, a significant amount of cortex can be present on a flake taken off near the very end of the reduction sequence. Removed flakes exhibit features characteristic of conchoidal fracturing, including striking platforms, bulbs of force, and occasionally eraillures (small secondary flakes detached from the flake's bulb of force). Flakes are often quite sharp, with distal edges only a few molecules thick when they have a feather termination. These flakes can be used directly as tools or modified into other utilitarian implements, such as spokeshaves and scrapers.

Lynford Quarry

Lynford Quarry is the location of a well-preserved in-situ Middle Palaeolithic open-air site near Mundford, Norfolk.

The site, which dates to approximately 60,000 years ago, is believed to show evidence of hunting by Neanderthals (Homo neanderthalensis). The finds include the in-situ remains of at least nine woolly mammoths (Mammuthus primigenius), associated with Mousterian stone tools and debitage. The artefactual, faunal and environmental evidence were sealed within a Middle Devensian palaeochannel with a dark organic fill. Well preserved in-situ sites of the time are exceedingly rare in Europe and very unusual within a British context.The site also produced rhinoceros teeth, antlers, as well as other faunal evidence. The stone tools on the site numbered 600, made up of individual artefacts or waste flakes. Particularly interesting were the 44 hand axes of sub-triangular or ovate form.The site was dated to Marine Isotope Stage 3 using Optically Stimulated Luminescence dating of the sand from the two layers of deposits within the channel.


A midden (also kitchen midden or shell heap) is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, sherds, lithics (especially debitage), and other artifacts and ecofacts associated with past human occupation.

These features, therefore, provide a useful resource for archaeologists who wish to study the diets and habits of past societies. Middens with damp, anaerobic conditions can even preserve organic remains in deposits as the debris of daily life are tossed on the pile. Each individual toss will contribute a different mix of materials depending upon the activity associated with that particular toss. During the course of deposition sedimentary material is deposited as well. Different mechanisms, from wind and water to animal digs, create a matrix which can also be analyzed to provide seasonal and climatic information. In some middens individual dumps of material can be discerned and analysed.

Prismatic blade

In archaeology, a prismatic blade is a long, narrow, specialized stone flake tool with a sharp edge, like a small razor blade. Prismatic blades are flaked from stone cores through pressure flaking or direct percussion. This process results in a very standardized finished tool and waste assemblage. The most famous and most prevalent prismatic blade material is obsidian, as obsidian use was widespread in Mesoamerica, though chert, flint, and chalcedony blades are not uncommon. The term is generally restricted to Mesoamerican archeology, although some examples are found in the Old World, for example in a Minoan grave in Crete.Prismatic blades were used for cutting and scraping, and have been reshaped into other tool types, such as projectile points and awls.

Retouch (lithics)

Retouch is the act of producing scars on a stone flake after the ventral surface has been created. It can be done to the edge of an implement in order to make it into a functional tool, or to reshape a used tool. Retouch can be a strategy to reuse an existing lithic artifact and enable people to transform one tool into another tool. Depending on the form of classification that one uses, it may be argued that retouch can also be conducted on a core-tool, if such a category exists, such as a hand-axe.

Retouch may simply consist of roughly trimming an edge by striking with a hammerstone, or on smaller, finer flake or blade tools it is sometimes carried out by pressure flaking. Other forms of retouch may include burination, which is retouch that is conducted in a parallel orientation to the flake margin. Retouch is often taken as one of the most obvious features distinguishing a tool from a waste by-product of lithic manufacture (debitage).

The extent of reduction, also known as the retouch intensity, is denoted by a measure of the reduction index. There are many quantitative and qualitative methods used to measure this.

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