Bipolar Flaking Research Articles

New Approaches to the Bipolar Flaking Technique: Qualitative, Quantitative, and Kinematic Perspectives

The bipolar technique is a flaking strategy that has been identified from 3.3 Ma until the twentieth century, with no geographical or chronological homogeneous distribution. It is represented by the intentional contact of an active percussive element against a core rested on an anvil. This tool composite has been described by some researchers as a sign of low-skill of hominins, unable to perform successfully free-hand flaking or for flaking low-quality raw materials. Based on this premise, our research focused on the following question: Are there any quantitative and qualitative differences in terms of both kinematic parameters and technical skills between knappers with different levels of expertise when flaking using the bipolar technique? To get an answer, we developed a systematic experimental program with 12 volunteer participants with different levels of expertise. Then, to assess potential quantifiable differences and to understand the mechanics of bipolar technology, we did a video motion analysis based on kinematic parameters (including position, velocity, acceleration, and kinetic energy of the hammerstone). In addition, we performed a technological analysis of the experimental lithic assemblages to assess the technological differences between knappers based on their levels of expertise. In kinematic parameters, both statistical analysis and observations from the experiment clearly show that there are differences between the levels of expertise in this technique. Intermediate knappers have been observed to apply more velocity and kinetic energy than experts and novices. Also, differences were observed in the flaking strategies. Expert knappers show a longer reduction sequence, while intermediates show shorter one. Moreover, some of the novice knappers did not even obtain a single flake. The results of our experiment stress the complexity of bipolar flaking and that previous assumptions about it might be reconsidered, especially in terms of reconsidering the negative connotations attributed to this flaking technique.

Particle size distribution: An experimental study using southern African reduction methods and raw materials.

We experimentally created a particle size dataset that is based on reduction sequences and raw materials typical of the Middle and Later Stone Age in southern Africa. The reason for creating this new dataset is that current particle size frameworks are based, almost exclusively, on flint and western European knapping methods. We produced the dataset using knapping methods and raw materials frequently encountered in the southern African archaeological record because we wanted to test whether it has the same distribution as particle size datasets experimentally created in Europe, and to initialise the production of a database for use in the analysis of lithic assemblages from southern African Late Pleistocene deposits. We reduced 117 cores of quartz, quartzite, jasper, chalcedony, hornfels, and rhyolite. The knapping methods selected were unidirectional, discoidal, Levallois recurrent and bipolar flaking. In this article we compare this new particle size distribution dataset with the results obtained from previous experiments. We found that the southern African dataset shows a wider size range distribution, which seems to be explained by differences in knapping methods and raw materials. Our results show that there is overlap between the distribution of the southern African experimental knapping dataset and the sorting experiment conducted by Lenoble on flint artefacts in a runoff context. This article shows that a particle size analysis is not sufficient on its own to assess the perturbation of an archaeological assemblage and must be coupled with other analytical tools.

Deriving original nodule size of lithic reduction sets from cortical curvature: An application to monitor stone artifact transport from bipolar reduction

Stone tools represent the largest source of information about past human behaviors on the planet. Much of the information about stone tools remains untranslated because we have little understanding about what the variation in artifact form means. One component of stone tool production that has less ambiguity is the reductive nature of the technology. Models of reduction rely on the ability to predict patterns of the rate of mass lost during artifact production. However, these patterns can vary quite substantially due to a variety of factors, one of which is variation in the original size of stone nodules prior to reduction. Here we report on a novel method to estimate the original size of stone nodules based on measurement of the curvature of residual cortex on flake and core products. Using experimental quartz bipolar reduction sets, we demonstrate the suitability of the approach, even when reduction intensity is high. Computer simulation with the experimental sets is then used to demonstrate the method’s utility for supporting archaeological inferences about land use and mobility from the analysis of bipolar assemblages. The bipolar flaking method is a technique that was used widely across the 3 million years of paleolithic tool production, yet analytically has received less attention that other modes of reduction. Methods developed here will help to expand understanding for this analytically challenging technological context.

The MIS 5a (~80 ka) Middle Stone Age lithic assemblages from Melikane Rockshelter, Lesotho: Highland adaptation and social fragmentation

Multidisciplinary research suggests that Marine Isotope Stage 5 (~130–74 ka) was an important evolutionary stage in African deep history. Population expansion and growth spurred changes in material culture as well as the exploration of previously unoccupied regions and ecosystems. The archaeological sequence at Melikane Rockshelter (1860 masl) in the Maloti-Drakensberg Mountains of highland Lesotho, southern Africa, stretches from the late Holocene back to sub-stage 5a, ~80 ka. The site's earliest strata represent one of the earliest known examples of a sustained human presence in high mountain systems worldwide. This paper deals with the lithic assemblages from those levels, which are currently the oldest radiometrically dated archaeology in Lesotho and one of the few stratified assemblages of Last Interglacial age in the southern African interior. The results of a typo-technological analysis of the assemblages are presented. They suggest that the afromontane foragers who resided at Melikane employed both blade-focussed and bipolar flaking systems, curated a maintainable toolkit suited to frequent residential moves, and used a hybrid provisioning system adapted to their immediate environment. Comparisons with other late Last Interglacial assemblages across the subcontinent suggest that highland populations at this time were largely disconnected from their lowland counterparts. This implies that as Last Interglacial populations in southern Africa expanded into new environments, they also fragmented, adapting to local conditions rather than adhering to a universal technological system.

A shell disc bead maker's workshop from Kavewa Island, northern Fiji

ABSTRACTTest excavations of an early Lapita colonising site on Kavewa Island off the north‐east coast of Vanua Levu in 2012 encountered an abundant assemblage of Anadara shell disc beads and preforms, as well as lithic micro‐drills for bead perforation. Concentrated in the upper strata of a 1 × 1 m unit, radiocarbon dates place this assemblage in the interval 2490–2280 calBP. Production stages (chaîne opératoire) in bead manufacture are described as is the fabrication of micro‐drills through bipolar flaking of small quartz, chalcedony and chert clasts, locally acquired from Malau breccia. A survey of the Oceanic literature relating to stone drills and shell bead production finds a comparable assemblage only at Bootless Bay, Motupore Island, Papua New Guinea. This assemblage, however, is 3500 km distant and 1750 years more recent in time. The production of beads and micro‐drills represents specialised expertise. Whether this supported an external exchange system, or was exclusively related to household use, cannot be determined.

A Lower Paleolithic assemblage from western Anatolia: The lithics from Bozyer

In 2005 the Central Lydia Archaeological Survey (CLAS) identified an open-air Lower Paleolithic site called Bozyer near Lake Marmara in the province of Manisa, Turkey. Intensive survey of Bozyer in 2008 resulted in collection of over 300 stone tools. Subsequent systematic analysis attributed 189 of these lithics to a Lower Paleolithic industry. The assemblage is characterized by flakes and retouched flake tools, many of which were produced with the bipolar flaking technique; preferential use of locally available quartz and quartzite over chert; a low proportion of cores, most of which were reused as choppers and chopping tools; and the absence of bifaces and other large cutting tools. With few exceptions, similar assemblages are rare in Anatolia, and comparable industries from Eurasia and the Near East date to the Early Pleistocene period. The lithic industry from Bozyer thus joins other nearby sites in evidencing some of the earliest hominin activities outside Africa, shedding new light on growing understandings of Lower Paleolithic technology, mobility, and activities in Anatolia.

Magnetostratigraphic and archaeological records at the Early Pleistocene site complex of Madigou (Nihewan Basin): Implications for human adaptations in North China

The Nihewan Basin in North China contains the densest concentration of early Pleistocene Paleolithic sites outside Africa. This paper introduces a new archaeological site complex at Madigou (MDG) that was systematically excavated from 2011 to 2014 in the northeastern part of the Nihewan Basin. The site contains fossils and well-preserved stone artefacts in fluvio-lacustrine sediments. Our magnetostratigraphic results situate the MDG sedimentary sequence in the early Brunhes normal chron and the late Matuyama reverse chron, including the Jaramillo normal subchron. The MDG artifact layers are positioned within the pre-Jaramillo Matuyama chron, with an estimated age of ca. 1.2 Ma, close to the onset of Mid-Pleistocene climate transition. The MDG core and flake technology includes bipolar flaking of siliceous dolomite cobbles, and freehand flaking of chert and brecciated chert block fragments. Mammalian fauna and pollen compositions indicate that the MDG hominins lived in an open habitat varying from lightly-wooded grassland to an ecosystem dominated by sparse steppe near the shore of the Nihewan paleolake. Our combined results in the fields of archaeology, paleontology, palynology and magnetochronology suggest that innovations in technological behavior may correlate with adaptations to high environmental variability during the start of Mid-Pleistocene climate transition.

Tecnología lítica en la sierra de El Alto-Ancasti (Catamarca). Aporte desde la experimentación

El cuarzo es la materia prima dominante utilizada para la talla en las ocupaciones prehispánicas de la sierra de El Alto-Ancasti, superando el 95% en todas las muestras hasta el momento estudiadas. Un análisis experimental permitió profundizar el conocimiento sobre los modos de producción de los artefactos líticos en esta roca, haciendo hincapié en las distintas técnicas de talla identificadas, la talla directa y la talla bipolar. Estas actividades fueron desarrolladas con la finalidad de obtener muestras comparativas a los conjuntos arqueológicos recuperados en algunos de los sitios de la sierra y explorar el potencial de esta materia prima para la confección de instrumentos, en función de sus propiedades mecánicas y aptitudes para la talla. El estudio que se propone contribuirá a la interpretación de las prácticas y elecciones tecnológicas de las poblaciones serranas y su relación con los recursos locales. Se pretende aportar así al conocimiento sobre las ocupaciones humanas del área y brindar datos específicos a la temática a nivel regional, sumando nueva información acerca de la materialidad lítica en contextos agro-pastoriles, atendiendo especialmente al tratamiento de una materia prima relativamente poco estudiada como el cuarzo.

Experimental flaking in the Danjiangkou Reservoir Region (central China): A rare case of bipolar blanks in the Acheulean

The exploration of techniques used to produce large flakes has long been a focus in Acheulean studies, especially from an experimental perspective. In this study we develop an experimental methodology to analyze Acheulean materials from the Danjiangkou Reservoir Region (DRR) in central China. The results show that large flakes experimentally produced with the bipolar technique can be easily distinguished from flakes produced by the other techniques due to the compression fracture unique to this method of flaking. These bipolar flakes show features consistent with those observed on a portion of the DRR archaeological handaxes. We suggest that the internal flaws and foliated structure found in quartz phyllite can actually assist in splitting cobbles, and consequently, they make bipolar flaking easier and effective. The anvil and throwing techniques have the next most successful ratio in detaching large flakes. The freehand technique is the least successful. Overall, the experimental study reported in this paper clearly demonstrates that raw materials influence the choice of flaking techniques, and the bipolar technique is a unique characteristic of the DRR Acheulean.

An experimental study of bipolar reduction at Zhoukoudian locality 1, north China

Bipolar reduction is usually connected with quartz material, and the less predictable fracture of quartz makes the recognition of bipolar products highly uncertain. At Zhoukoudian locality 1 (ZKD1) in north China, numerous bipolar reduction artifacts were reported, and this has become a major technological label of the lithic industry. However, few experimental analyses have been conducted on this site. This study conducted experimental analysis to build an experimental referential framework for distinguishing bipolar products, and then chose a small lithic artifact sample from layers 4–5 to evaluate the role of bipolar reduction. These data show freehand reduction produces a higher percentage of usable flakes and also more cutting edges per flake than that by bipolar reduction in general. More freehand reduction flakes were chosen as tool blanks than bipolar flakes. The contribution of the bipolar flaking method to the lithic industry of Zhoukoudian locality 1 has been overestimated. This paper proposes that bipolar reduction is likely to have been an expedient strategy as a supplement of freehand reduction at Zhoukoudian locality 1. Consequently, it should be seen as an adaptive characteristic of the industry instead of an evolutionary one, and also cannot be used to trace technological diffusion or cultural tradition.

Métodos de talla y estrategias de reducción en la fabricación de foliáceos en el III milenio A.N.E. [Knapping methods and reduction strategies in leaf-like projectile production in the 3rd millennia B.C.E.

In this paper we present a technological study of leaf-like arrow points recovered in an open-air site from the 3th millennium B.C., named El Tossal de La Munda (Vistabella del Maestrazgo, Castellon). It is located at the central east of Spain, in the southern part of Iberian range in a mountainous area about 100 km far from the coast. The site is on a small flat-topped hill of about 5000 m² and it is 820 m.a.s.l. The upper surface has been strongly eroded and the lithic material has been found directly on the bedrock or over the dissolution clays. We recovered close to 5000 lithic remains, offering an assemblage mainly produced in the 3rd millennia BC: retouched blades and flakes as main groups, leaf-like arrow points, in addition to some other retouched tools as segments (one triangle, one bifacial circle and a trapezoid), scrapers, end-scrapers, denticulate and notches, one raclette and one drill. We also found two small adzes. The cores were intensively exhausted. Just some of them show bladelet scars but most of them are small discoid and irregular shaped cores for the production of small flakes. Few of them show marks of bipolar flaking on anvil. Within the lithic assemblage there is a sample of 73 bifacial rough-outs and projectile points at different reduction stages, from initial blanks to finished and used ones. In addition, we found one refit and one conjoint. All of them are leaf-like arrow points except a fragment showing shoulders as an exception. We have identified some typical accidents in bifacial reduction: fractured rough-outs, overshot flakes, overshot negatives and another accident that we named “bending notches”, linked principally to the pressure technique (two positives and two negatives). We analysed both preforms and finished leaf-like arrow points from a technological point of view, first trying to identify the blank type and shape, and secondly trying to distinguish knapping methods and techniques. We have divided the methods in three main types: parallels (adjacent and contiguous), alternating, and independent method. We have identified the strategies according to edges and blank faces management. In our case, only simple combinations has been detected, mainly alternate (first one face, after the other side on the same edge). We have divided leaf-like production in five technical stages, and we described the identified knapping methods and strategies used at the site according to the reduction stage. In order to show this, we describe in the paper the most significant cases of the site. The identification of blanks has been possible in most of the rough-outs, verifying that the blanks used at the site were irregular and cortical flakes, chunks, fissure slabs and small cores. Despite this, leaf-like production at the site was really homogeneous, applying the same methods and also managing the blank faces similarly. Alternate strategy is completely dominant, firstly removing the ventral face, secondly the dorsal part. The main knapping method used at the site is the independent method, removing consecutively the most highlighted ridges. When the sketch is advanced and reaches a regular shape, the application of parallel method series is common. Technically we have observed two phases: first direct percussion (mainly with stone hammer); second, pressure technique. Heat modifications have been detected in 20 rough-outs and projectiles but most of them seem to be non-intentional, exhibiting cupules and cracks. Most of the finished ones do not show double shine (heat patina). According to this, we state that leaf-like production at the site was not a specialized process but it recovers to use as blanks previously discarded flakes, chunks and exhausted cores, part of them recycled before burning. The elaboration of leaf-like arrow points was embedded in the laminar production, and it played a marginal role within a lithic reduction system that is focused on blade and bladelet production. They used mainly cortical and non-cortical flakes, that seem to be by-products of blade core preparation, or exhausted cores that were reused for this purpose. Despite most of the arrow points result in crude and thick foliated shapes, we argue that in this technological context, the use of waste as blanks constrains the knapping reduction, and lead to rude shapes. Derived from this, we discuss on the leaf-like arrow point morphology and its profitability, the resistance of thick-elliptical tips and their role in the technological framework of the site and its landscape. We also discuss about the visibility of the skilled knapping in this context, when small, irregular and cortical flakes, burned chunks and exhausted cores were used as a blank to make leaf-like projectiles.

Menez-Dregan I, layer 4: A transitional layer between the Lower and Middle Palaeolithic in Brittany

Menez-Dregan I is a Lower Palaeolithic site situated at Plouhinec, Finistère, in Brittany. It is an ancient marine cave whose roof has gradually collapsed. Layer 4 from the site of Menez-Dregan I is the last occupation of this deposit, at the boundary between the Lower and Middle Palaeolithic. Geological correlations tend to place layer 4 in MIS 9 or 7, although the only TL dating obtained for this level gave an age of 223 ± 23 ka. This study focuses on the lithic industry from the 1991–2004 excavations and was undertaken in order to capture the various types of technical behaviour that could illustrate the transition between the Lower and Middle Palaeolithic. We present the lithic industry of this layer, which simultaneously combines Lower Palaeolithic characteristics, such as large quantities of pebble tools (due to the environment of the site), and the emergence of characteristics that are common to the Middle Palaeolithic, such as standardisation of flake production, or adapting knapping methods to the dimensions of the raw materials (discoid knapping for quartzite, bipolar flaking on an anvil for small flint pebbles). The lithic industry from layer 4 and its three levels (4a, 4b and 4c) has been analysed. Layer 4 of Menez-Dregan I has been attributed to the “Colombanian” on the basis of the composition of its lithic industry: a predominance of cobble tools amongst heavy-duty tools, retouched light-duty tools on flake-supports comprising mostly notches and denticulates, and a knapping method akin to the “SSDA – Clactonian”. The Levallois method is absent, bifaces are absent or extremely rare, and there are few scrapers. The Colombanian proves to be a Lower Palaeolithic industry contemporary with the classic Acheulean, but typologically distinct. However, standardisation of flake production leads us to foresee a change in the lithic industry of layer 4, and highlights a transitional period from the Lower Palaeolithic to the Middle Palaeolithic in the latest occupation of this deposit. This study is a contribution to the documentation of the diversity and variability of Lower and Middle Palaeolithic lithic industries, demonstrating that the large amount of cobble tools in layer 4 is an unchanged component due to environmental constraints.

The origins of stone tool reduction and the transition to knapping: An experimental approach

A reassessment of many of the archaeological assemblages older than two million years has resulted in a general consensus that the earliest Oldowan artifacts were made by skilled toolmakers who had a clear understanding of the fracturing mechanics of different toolstone materials. This has led several researchers to propose a simpler lithic reduction stage that occurred prior to 2.6Ma. Three lithic reduction techniques that are within the behavioral repertoire of our closest living relatives in the genus Pan are proposed as potential intermediate stages between the percussion behaviors of the last common ancestor of chimpanzees and humans and the skilled knapping of the Oldowan toolmakers. These include direct and indirect projectile percussion and bipolar flaking techniques. Measures of productivity, expediency, and efficiency were obtained and compared between these three reduction techniques and novice freehand knapping in order to better understand some of the factors that influenced how early hominins with little to no understanding of lithic fracturing mechanics achieved sharp flake tools. The provisional results of this proof-of-concept experiment indicate that, of these four conditions, dropping or throwing a large hammer stone on a brittle core is the most efficient way to exploit a core, while bipolar flaking is the most expedient method; however, novice freehand knapping creates the most productive flakes with large, sharp cutting edges. Thus, the transition to knapping in the late Pliocene may have been due to a shifting emphasis on productive toolmaking over expediency or efficiency.

Experimental protocols for the study of battered stone anvils from Olduvai Gorge (Tanzania)

Percussive activities are highly relevant in the economy of modern hunter-gatherer societies and other primates, and are likely to have been equally important during the Palaeolithic. Despite the potential relevance of percussive activities in the Early Stone Age, attempts to study battered artefacts are still rare. In order to establish protocols of analysis of battered tools, this paper pursues an interdisciplinary approach combining techno-typological, refit, use-wear and GIS studies of experimental anvils from Olduvai Gorge (Tanzania). The main aim is to classify types of damage on battered artefacts according to the percussive task performed, and hence identify patterns that can be used to interpret the Oldowan and Acheulean evidence. Our results indicate that abrasion marks on anvil surfaces are typical of nut cracking, while bone breaking leaves characteristic scars and abrasion marks on the edges of anvils. Pounding of soft materials such as meat and plants also causes battering of anvils, producing morphological and spatial patterns that can be discerned from the heavy breakage of anvils during bipolar flaking. By integrating macroscopic, microscopic and spatial analyses of experimental stone tools, this paper contributes to create a referential framework in which Early Stone Age battered artefacts can be interpreted.

La gestion du quartz au Pléistocène moyen et supérieur. Trois exemples d’Europe Méridionale

Quartz is one of the main lithic resources employed along the Pleistocene for the manufacturing of tools. The abundance in all kind of environments leads to its frequent presence in archaeological sites. In spite of its suitability for knapping, the scarcity of specific researches on quartz industries has led to a view of this raw material as a second-rate resource, only used when flint was not available in the surroundings. Quite in opposition to this prejudice, the familiarity with the petrological and mechanical properties of the different varieties of quartz has led the Middle/Upper Pleistocene groups to a rational and differential exploitation of the available resources. There is a distinct selection of the varieties attending to the purposes of the exploitation and configuration. The patterns of exploitation of the cores are very standardized, based on longitudinal extractions and documenting the bipolar flaking technique. Moreover, when the raw material is of good quality, more sophisticated reduction methods such as the discoidal or the Levallois may be employed. On the other hand, for the purposes of configuration a clearly differential management of the raw material is attested: thus quartz is used for the small products (denticulates, side-scrapers, notches), while other stones (quartzite, porphyry and others) are devoted to the manufacturing of those tools demanding a more complex control of the elaboration (bifaces, cleavers, etc.). Either acting as the main lithic resource or as a complement to other raw materials, we can observe through the technological analysis of these lithic collections the great conceptual complexity depending on the needs to be fulfilled. Raw material quality allowing, the state-of-the-art technology of knapping can be applied to the quartz and, therefore, we should not understand its use as a consequence of environmental constrictions but rather as a result of the variability of the procurement strategies and management of lithic resources among the prehistoric communities.

Technical microwear and residues in identifying bipolar knapping on an anvil: experimental data

The functional study of the stone tool artefacts from the Middle Pleistocene site of Isernia la Pineta (Molise, central Italy) revealed microtraces that display certain features that did not fit in with what we know as use-wear traces. The suspicion that these microtraces may be technical traces derived from bipolar flaking, which is prevalent at this site, led us to initiate an experimental programme to check our hypothesis. The experiments conducted allowed us to identify residues associated with bipolar flaking on an anvil and to characterise the microscopic traces derived from this production technique. Our results proved very useful in identifying the artefacts produced by bipolar flaking, as well as in determining the basic lithological features of the anvil. Moreover, these experiments allowed us to assess the possible interferences that these kinds of technical traces can cause when performing the functional analyses of lithic assemblages produced by the bipolar technique.

Evidence for the earliest Pleistocene hominid activity in the Nihewan Basin of northern China

The Nihewan Basin in North China contains the densest concentration of early Pleistocene Paleolithic sites outside Africa. This paper introduces a new archaeological site complex at Madigou (MDG) that was systematically excavated from 2011 to 2014 in the northeastern part of the Nihewan Basin. The site contains fossils and well-preserved stone artefacts in fluvio-lacustrine sediments. Our magnetostratigraphic results situate the MDG sedimentary sequence in the early Brunhes normal chron and the late Matuyama reverse chron, including the Jaramillo normal subchron. The MDG artifact layers are positioned within the pre-Jaramillo Matuyama chron, with an estimated age of ca. 1.2 Ma, close to the onset of Mid-Pleistocene climate transition. The MDG core and flake technology includes bipolar flaking of siliceous dolomite cobbles, and freehand flaking of chert and brecciated chert block fragments. Mammalian fauna and pollen compositions indicate that the MDG hominins lived in an open habitat varying from lightly-wooded grassland to an ecosystem dominated by sparse steppe near the shore of the Nihewan paleolake. Our combined results in the fields of archaeology, paleontology, palynology and magnetochronology suggest that innovations in technological behavior may correlate with adaptations to high environmental variability during the start of Mid-Pleistocene climate transition.

Gestión del cuarzo y la pizarra en el Calcolítico peninsular: el “Santuario” de El Pedroso (Trabazos de Aliste, Zamora)

The analysis of the lithic artifacts from the “Santuario” sector of El Pedroso has allowed us to determine a strategy of exploitation of the local raw materials, mainly quartz and slate. The specific mechanical properties of those materials led the prehistoric people to the adoption of technical solutions such as bipolar flaking, with the aim of overcoming the structural difficulties posed by this type of rocks.

Backed to the Pleistocene

AbstractThe recent identification of Australian backed artefacts dating to the early Holocene by Hiscock and Attenbrow (1998) opens the way for new explorations into the origin, distribution and use of these implements across Sahul. In particular, it draws attention to the fact that the technology of backed artefact production should not be seen as innovative but as an adaptive response to changing technological demands on stone tools. Using information on bipolar flaking and anvil retouching from Pleistocene Tasmania, I argue that backing has been part of the technological repertoire of Aboriginal Australians for at least 30,000 years. These new data suggest that understanding the appearance of backed artefacts at different time periods and at different places, including the major efflorescence in the last 4500 years, has more to do with local changes in technological organisation (particularly the use of hafting) and the relative application of existing flaking techniques using anvils rather than diffusion of a new technology with possible Asian origins. Results have implications for the integrity of the Core Tool and Scraper Tradition.

Tool Kit Entropy and Bipolar Reduction: A Study of Interassemblage Lithic Variability among Paleo-Indian Sites in the Northeastern United States

Bipolar flaking as a means of reducing lithic raw material is known to have occurred since the time of the Lower Palaeolithic. As a strategy for working small bits of raw material, it is probable that it has a variety of important selective contexts. Assemblages from northeastern United States Paleo-Indian sites are used to test the hypothesis that bipolar artifacts in these systems represent a method of extending the utility of a transported, highly curated lithic toolkit through recycling. It is shown that what have been called pièces esquillées among these sites are in all probability cores for the derivation of small flakes. This is demonstrated by citing ethnoarcheological and technological data and by a spatial-statistical analysis of the distribution of “pièces esquillées” at the Debert site. The methodological problems related to the accurate functional identification of artifacts are explored and their impacts on archaeological arguments are also discussed. Also discussed are the difficulties in interpreting site activities on the basis of inter site differences in tool frequencies and proportions where assemblages have been affected by lithic recycling. Last, the theoretical significance of recycling through bipolar reduction is outlined as a strategy for solving the raw material and tool replacement problems as conditioned by Paleo-Indian settlement and technological systems.