Blade Technology Research Articles

Approach to the blade technology analysis of the Upper Palaeolithic site of “Tajos de Marchales” (Granada, Spain)

The study of the Upper Palaeolithic in the South of the Iberian Peninsula is usually addressed from a few stratigraphic sequences recognized in the region. We can say that the upper Palaeolithic in Andalusia is one of the worse known stages of regional prehistory. On the other hand, its development has just surpassed the description of the typological formal characterization. In some cases, recent contributions in the central region of the Baetic Mountain range, confined to the province of Granada, appeared during the last century.In this sense, the present study has two objectives. On one hand, to present the site of the rockshelter 3 of the “tajos de Marchales” (Colomera, Granada, Spain), as a new Magdalenian site in the mountainous area of Sub-Baetic Andalusia.On the other hand, through the application of diacritic analysis on cores, unretouched material and tools recognisable, we present the technological characterization of different chaîne opératoire from the production supported by the main idea of different typological objectives (domain of burins, scrapers and to a lesser extent with backed edge blades). We distinguish the different operational sequences aimed at the generation of the artefactual set. All of this will allow us to obtain a global comprehension of the lithic assemblages from the site, and to define the beginning of its chaîne opératoire. The work presents and discusses the distinctive traits of the different technical elements, focused on laminar production (blades and bladelets) and knapping methods.

Human resilience to Lateglacial climate and environmental change in the Scheldt basin (NW Belgium)

Recent palaeoenvironmental analyses in the Scheldt basin in NW Belgium have identified significant hydrological and vegetation changes between Greenland Interstadial-1b (GI-1b) and Greenland Stadial-1 (GS-1)/Younger Dryas (YD) that enable us to develop hypotheses to explain the radical changes in land-use and lithic technology observed between the Federmesser and post-Federmesser occupation of the region. The highly productive lacustrine environments of the lower Scheldt basin during the Allerod enabled relatively high population packing by Federmesser groups exploiting the region within a residential mobility system. Federmesser assemblages indicate a flexible lithic technology centered on the production of unstandardized blades and flakes that were intensively backed to shape various tool forms. The destabilization of these landscapes in the Scheldt basin between GI-1b and GS-1/YD, and the ensuing cold of the YD, changed the composition of important secondary biomass from less mobile ungulate species to seasonally mobile reindeer populations. Human populations were resilient to these changes by developing a highly standardized (micro)blade technology and microlithic toolkit.

From flint to quartz: Organization of lithic technology in relation to raw material availability during the pioneer process of Scandinavia

Formal technologies and intensified reduction are often seen as responses to increased mobility and low abundance of lithic raw material of good flakeability and controllability. In this paper, we discuss an alternative explanation to this hypothesis using the change in tool raw material experienced by flint-using pioneers, as they had to go from a formal blade technology to a simple flake technology as they settled in Scandinavia. The region is dominated by quartz, and we use use-wear data as a means to evaluate the role of this type of raw material compared to the use profile of flint assemblages in the home territories of the pioneers. Although the technology changed through simplification and loss of formal production rules, due to the low workability of quartz, we conclude that changes in the foraging range into areas of different quality tool raw materials does not need formalization of the technology. The quartz in our sample was produced with a simple platform/bipolar technology and used for a wide variety of activities in every aspect comparable to the range of uses identified in the contemporaneous blade assemblages based on flint. Instead of formalization of the lithic technology to cope with different quality raw materials, it was diversified and simplified. The organisational dimensions and design criteria of the bone technology, whereby simple flakes were used as insets in slotted tools, did not have to change in this process.

Reconstructing the last stages of bidirectional blade technology in the Levant: North and South (dis)connections

Cet article livre une mise à jour et une chronologie des derniers stades de l’évolution du débitage laminaire bidirectionnel dans trois régions du Levant, connaissant des écosystèmes différents : la moyenne vallée de l’Euphrate au Levant Nord, le désert syrien (bassins d’El Kowm et de Douara), et la Galilée au Levant Sud. Malgré des similitudes dans la nature même du processus évolutif, cette approche comparative met en avant des disparités à travers le Levant. Il y a des différences majeures en termes de chronologie des changements techniques observés et suivant les contextes socio-économiques au sein desquels le débitage bidirectionnel est délaissé ; elles suggèrent l’existence de divers facteurs ayant entraîné l’abandon de ce qui constituait la culture matérielle lithique la plus commune au Levant durant le PPNB.

The Canaanean Blades from Tel Yarmuth, Israel: A technological analysis

L’analyse technologique du matériel de Tel Yarmouth offre de nouvelles perspectives sur la nature du débitage cananéen et sur la structure de cette production très élaborée en la replaçant dans la société de l’âge du Bronze ancien. L’étude détaillée de tous les éléments de la production, débris, produits bruts et outils, montre clairement l’utilisation de la technique de la pression au levier. La présence dans le site de toutes les phases de la chaîne opératoire, y compris la collecte et la réduction de nodules, le débitage des lames et la transformation des lames en outils, indique que la production avait lieu sur place. L’absence de preuves d’un atelier proprement dit suggère que les lames étaient importées comme biens d’échange depuis des ateliers hors site, probablement par les tailleurs, et produites sur demande par ces mêmes tailleurs. En considérant le savoir-faire et les connaissances impliqués, le nombre de lames que chaque spécialiste pouvait produire et la répartition des débris, aussi bien à Tel Yarmouth que dans d’autres sites, la reconstruction de cette production spécialisée et de son système d’échange suggère que seul un nombre limité de tailleurs était engagé dans la production des lames cananéennes.

Aero engine compressor fouling effects for short- and long-haul missions

The impact of compressor fouling on civil aero engines unlike the industrial stationary application has not been widely investigated or available in open literature. There are questions about the impact of fouling for short- and long-haul missions comparatively, given their unique operational requirements and market. The aim of this study is to quantify the effects of different levels of fouling degradation on the fan, for two different aircraft with different two-spool engine models for their respective typical missions. Firstly, the study shows the increase in turbine entry temperature for both aircraft engines, to maintain the same level of thrust as their clean condition. The highest penalty observed is during take-off and climb, when the thrust setting is the highest. Despite take-off and climb segment being a larger proportion in the short-haul mission compared to the long-haul mission, the percentage increase in fuel burn due to fouling are similar, except in the worst case fouling level were the former is higher by 0.8% points. In addition to this, for all the cases, the additional fuel burn due to fouling and its cost is shown to be small. Likewise, the increase in turbine entry temperature for both missions at take-off are similar, except in the worst case fouling level for the short-haul mission were the turbine entry temperature is 7 K higher than the corresponding long-haul mission for the same level of degradation. The study infers that the penalty due to rise in temperature is of more concern than the additional fuel burn. Hence the blade technology (cooling and material) and engine thrust rating are key factors in determining the extent to which blade fouling would affect aero engine performance in short- and long-haul missions.

Striking a difference? The effect of knapping techniques on blade attributes

Studies of lithic blade technology offer an important step towards explanations of technological diversification among Stone Age hunter-gatherers, and for tracking continuity and change in cultural traits through time and space. One prominent example is the many efforts to map the spatiotemporal diffusion of pressure blade technology. In this context, a key concern is to distinguish the various knapping techniques, applied by prehistoric knappers. Specific observable blade attributes, found by experimental work is proposed to provide essential information, to determine the technique used. To date, however, the causal relationship between blade knapping techniques and postulated technique-related attributes remains largely untested in quantitative terms. With the purpose of contributing to a better understanding of how various knapping techniques, and in this case the indentor type used for blade removal, effect particular aspects of blade morphology, statistical analysis of experimental data is used, and subsequently applied as a basis for predicting knapping techniques in blade assemblages from Early and Middle Mesolithic (ca. 9500–6300 cal. BC) Southern Norway. The results clearly indicate a considerable overlap in the distributions of the majority of the attributes with regards to technique, and that their causal relationship should be viewed with considerable caution. The discriminate capability increases, however, when specific composite attributes are considered. Importantly, what is also shown is that at the blade population level, results from statistical analysis of experimental data contribute to predict general tendencies in knapping technique variability in archaeological blade assemblages, while simultaneously formalising the discriminating characteristics that differentiate those assemblages. Taken together, these results have implications when investigating variation and change in blade technology in time and space.

Modeling and Development of Cooling Technology of Turbine Engine Blades

The paper aims to develop adequate means to measure the effectiveness of cooling technology of turbine blades. The used methodologies are the mathematical modeling of movement and heat transfer in the boundary layer of the working medium near the curved surface of the turbine blade and also using empirical data on the critical flow regimes. The mathematical model of film cooling of turbine engine blades under film formation on the punched surface with blind damping cavities is offered. On the basis of numerical research with the use of the offered model the option for essential (providing in analyzed conditions decrease in adiabatic temperature of a wall on 200 K) increase in efficiency of film cooling at the expense of a partial laminarization of a turbulent interface on the punched surface is revealed.

Rethinking the origin of microblade technology: A chronological and ecological perspective

There are four hypotheses on the origin of microblade technology in North China: i) that it originated from Siberia before the Last Glacial Maximum; ii) that it emerged in Siberia after the Last Glacial Maximum; iii) that it developed from the long-narrow flakes produced by the long-established knapping tradition in North China; and iv) that it had multi-regional origins, among which, a microblade industry may have emerged from the bipolar technology in northern China. Based on archaeological data from Siberia, Mongolia, the Japanese archipelago, Korean Peninsula, and North China, it is reasonable to say that the technological groundwork of Siberia was more substantial, and the initial microblade technology appeared in Siberia earlier than in the other areas. Microblade technology was involved in core preparation, systematic knapping, soft hammer and indirect/pressure flaking techniques, which were all present in the blade technology in Siberia but hardly ever evidenced in the traditional flaking technology systems in North China. It is well accepted that the microblade technology was closely related the high mobility of foragers to live in harsh environments. The climatic fluctuations of the last glacial in Siberia were more severe than in low latitudes, and placed greater subsistence pressure on hunter–gatherers in Siberia. The advantages of the initial microblade technology in dealing with these hostile circumstances encouraged foragers to employ and develop it, and finally generated its widespread use during the Upper Paleolithic through human migration and cultural transmission in Northeast Asia and North America.

Honeycombed TiO2 films prepared by combining breath figure and sol gel methods

TiO2 films with honeycombed microstructure were coated on glass substrate by introducing breath figure method to sol gel route, and by dip coating and doctor blade technology respectively. The effect of some factors on the formation of honeycombed microstructure was investigated. Field-emission scanning electron microscope and optical microscope observations indicate that a pulling speed of 15–30cm·min−1, a mixed solvent of Vcyclohexane/Vbutanol=3–7 and a bath water temperature of 50–60°C were favorable for the formation of homogenous honeycomb pattern on TiO2 film. Furthermore, the traditionally breath figure method was modified by decreasing the substrate temperature below 0°C. By this modification, honeycombed pattern with bimodal pore size distribution was produced without a moist flow. This modification broadens the application of breath figure method, and the obtained film modified with nanoscale and microscale pores may provide potential research value for surface science.

BLADE AND MICROBLADE INDUSTRIES IN NORTHERN, EASTERN, AND CENTRAL ASIA 1. AFRICAN ORIGIN AND SPREAD TO THE NEAR EAST

Being the first in a series, this study addresses the place of the blade industry among those of Africa and Eurasia, and its origin and evolution in southern, eastern and northern Africa. The blade technology first appeared in the Kapturin Formation some 500 ka BP. The Middle Stone Age industries of southern, eastern, and northern Africa were mostly based on the Levallois technique, which included points, blades, and flakes; and on radial flaking. In the late Middle and early Upper Pleistocene, two principal technologies, Aterian and Nubian, emerged in northern and northeastern Africa; whereas the principal industries of southern and partly eastern Africa were Howieson's Poort (whose primary reduction technique was basically Upper Paleolithic), and an industry on predominantly geometric tools. Both were associated with anatomically modern humans, who migrated to Eurasia at various stages of the Upper Pleistocene.

Regional variability in late Lower Paleolithic Amudian blade technology: Analyzing new data from Qesem, Tabun and Yabrud I

The Acheulo–Yabrudian Cultural Complex (AYCC) of the late Lower Paleolithic Levant consists of three major industries, one of which is the blade-dominated Amudian. This paper provides an in-depth comparison of the Amudian blade industry from three major AYCC sites in the Levant – Qesem Cave, Tabun Cave and Yabrud Rockshelter I. The results demonstrate high inter-site similarity in Amudian blade technology and in product (blades) characteristics – i.e., a regional, clearly defined Amudian blade production technology. Nevertheless, differences in particular technological choices along the reduction sequences of blade production between the sites represent minute sub-regional technological variability within the Amudian. The evidence presented in this paper, together with many other innovative behavioral patterns seen in the AYCC, especially as reflected at Qesem Cave, may mark the end of a Lower Paleolithic Acheulian way of life that lasted over a million years in the Levant, and the beginning of a new era.

Archaeological evidence for indigenous human occupation of Southern Arabia at the Pleistocene/ Holocene transition: The case of al-Hatab in Dhofar, Southern Oman

The Neolithic peopling of Arabia is a subject of increasing debate, as different scenarios are proposed to describe the relatively sudden appearance of seemingly homogeneous archaeological sites throughout the south of the Peninsula during the Early Holocene. Such sites are identified by the co-occurrence of a laminar core reduction strategy with its supposed fossile directeur, the “ Fasad point.” This techno-typological package has been used by some to link these sites with an expansion of pastoralists from the Levant. A recent study of blade technologies in Southern Arabia, however, demonstrates a large degree of internal variability within these reduction strategies, whilst an inter-regional study of Fasad points reveals this artifact category to be both time-transgressive and morpho-metrically variable across parts of Southern Arabia. Archaeological findings from al-Hatab Rockshelter in Dhofar, Oman go further to challenge the notion of an expansion originating in the Levant and spreading across Southern Arabia. Here we demonstrate that an indigenous occupation with a blade technology and tanged points pre-dates the ‘ Levantine expansion’ by at least four millennia. Based on the lithic assemblage from al-Hatab, we argue the Arabian Late Palaeolithic developed locally in Southern Arabia, forming part of the previously defined Nejd Leptolithic tradition. The evidence from al-Hatab in conjunction with recent genetic findings indicates that some groups in Southern Arabia have persisted there since the Late Paleolithic ca 13,000 years ago, if not earlier.

The Design of Arctic Small Tool Tradition Toolkits: An Example from Matcharak Lake, Alaska

This article presents the results of an analysis of stone tools and debitage from a 3600–4000 cal BP Arctic Small Tool tradition (ASTt) component at Matcharak Lake (AMR-186), located in the Alaskan Brooks Range. The goal of this study is to understand how ASTt technology is organized at a caribou hunting camp located far from a high quality toolstone source, and to use this information to evaluate ASTt mobility and settlement patterns in northern Alaska. Reconstructions of the stone-tool reduction sequences demonstrate that ASTt people made use of blade and biface technologies, but they primarily transported small finished tools and biface cores to produce large flakes for tool blanks and microblade cores. The stone-tool assemblage recovered from at Matcharak Lake is one designed to maximize utility, transportability, and relatively rapid production, which is an adaptive feature of a culture that has high residential mobility in an environment with limited access to raw material sources and an economy specialized on caribou.

Improvement in the casting technology of blades for aviation gas-turbine engines made of TNM-B1 titanium aluminide alloy produced by induction crucible melting

Properties of the TNM-B1 γ-titanium aluminide alloy are investigated in order to find reliable results of a simulation of casting processes used to produce the blades of gas-turbine aircraft engines. Thermal properties of the TNM-B1 alloy are experimentally determined using the methods of differential scanning calorimetry (DSC), laser flash analysis (LFA), and dilatometry (DIL). Various variants of gate-feeding systems for the production of cast blades using a vacuum induction melting furnace (Consarc, Scotland) in conditions of the Ufa Engine Production Association (OAO UMPO) are considered. The test casting is obtained and its defects are analyzed. A good correspondence of results of simulation to the actual centrifugal filling of blades is shown.

The Paleoamerican Occupation of the Plains of Uruguay: Technology, Adaptations, and Mobility

This paper presents results of investigation of an early archaeological site in Uruguay, and considers its position on a regional scale. Pay Paso 1 is the first early site of Uruguay to yield both artifacts and faunal remains including records of Pleistocene fauna (Equus sp. and Glyptodon sp.) in a radiocarbon-dated stratigraphic context. From stratigraphic, chronological and archaeological observations, three cultural components for the Pleistocene-Holocene transition have been identified, together representing one of the most intensively AMS dated sites in South America. This solid chronological base allows the positioning of the peopling of Uruguay in the context of the early settlement of the surrounding region including northeastern Argentina and southern Brazil. The site is also remarkable because it yielded evidence of a blade technology at 12,802 cal yr BP, with numerous blades and a depleted blade core, which, together with the records from Laguna Canosa and K87 (Arroyo del Tigre), permit the definition of the Tigre and Pay Paso Paleoamerican cultural complexes. Tigre and Pay Paso bifacial points were produced in post-Fishtail times in the Low Plains, a vast open territory in Uruguay and southern Brazil.

Errata

Blade Technology in Clovis Assemblages in Kentucky: A Brief Comparison with Old World Technologies (Vol. 35:1, pp. 1–36, 2014) In discussions with Dr. Metin Eren regarding the characterization of his work with Dr. Brian Redmond on the Paleo Crossing Site, it has become clear we made an error in understanding. Eren has explained to the authors that in using the word “prominent” to characterize blades in Clovis assemblages, his intention was to point out that their presence is noteworthy and not to comment on their frequency. It is clear in our conversations and review of his paper, that there are no explicit statements regarding the numbers or proportions of blades at the Paleo Crossing Site or throughout Clovis culture as a whole. We apologize to Eren and Redmond for this misunderstanding and retract our statements in regards to their excellent study. Crista M. Haag, MA, Principal Archaeologist

Aterian lithic technology and settlement system in the Jebel Gharbi, North-Western Libya

The Aterian represents one of the multiple facets of the Middle Stone Age (MSA) and has become increasingly important in the context of understanding modern human origins. In this paper, we present the results of our study on the Aterian in the Jebel Gharbi, North-Western Libya, from a regional point perspective. A total of 1567 lithic objects were analysed for this work from twelve different Aterian assemblages. The results of this analysis show a wide range of economic behaviour, possibly suggesting different site functions, within the three main areas (Ain Zargha, Jefara and Wadi Ghan). It is unlikely that any of these assemblages represents a residential site. Instead, we argue that the assemblages in the study are more likely to be the result of a logistic land use. Technologically, they exhibit all the distinctive features of the Aterian technocomplexes: coexistence between Levallois and blade technology, presence of tanged pieces and bifacial foliates, as well as of “Upper Palaeolithic” tools, together with a majority of sidescrapers and endscrapers. Only a combination of these features, and certainly not one of them alone, can characterize an assemblage as “Aterian”.

Functional analysis of prismatic blades and bladelets from Pinson Mounds, Tennessee

Hopewell prismatic blade industries are a standardized technology but not a specialized one. Exactly why they are ubiquitous and synonymous with Hopewell is a puzzle. That Hopewell prismatic blade technology satisfied basic tool needs concurrent with efficient usage of toolstone are beyond dispute. Prismatic blades from Pinson Mounds and other Hopewell sites in the Midwest and Southeast United States were simple, easily repaired, modular tool forms of variable usage. This functional evaluation of 125 artifacts documents far distant preferential exploitation of prismatic blade toolstone sources within the Ohio River valley and its tributaries, reveals statistically significant differences among seven technological types, explicates a production chain model for burins, and argues that prismatic blade technology had an equal or greater social meaning and identity as a quintessential symbol of the Hopewell Interaction Sphere.

Early Holocene blade technology in southern Brazil

This article presents the results of the technological analysis of assemblages from the sites of Alto Alegre 3, Linha Policial 1 and Linha Policial 3 in the states of Santa Catarina and Rio Grande do Sul (Brazil), dated to the Early Holocene. Alongside other reduction sequences, these sites also present sequences for exclusive blade production, described for the first time for Brazilian prehistory. Despite the lack of cores, analysis of the blades has established that: (1) blade production took place using a single method, with centripetal core initialization and unidirectional production; (2) knapping techniques by direct hard and soft percussion were both used to produce blades; and (3) the blades obtained were destined for different functions, the active part mainly lateral and sometimes used without retouch. This study presents an example of obvious technological convergence, since blade production is known in other prehistoric contexts throughout the world without historical links with that observed at the three sites analyzed here. It also shows the necessity of developing detailed technological analyses to understand the settling of South America in all its complexity.