Metal Tools Research Articles

Western Message Petroglyphs: A Faux Indian Picture-Writing Project in the American West

The term “Western Message Petroglyphs” (WMPs) refers to a number of petroglyph sites found scattered among eight western states that are recognized by their shared image content and layout. The imagery is drawn largely from a mash-up of late historic Native American sign-gesture language and picture-writing traditions inter-mixed with pan-cultural imagery from around the world. An increasing number of sites that fit this mold have been reported over the past 85 years or so, currently numbering 39 in all. There is no question that these sites date to post-European contact based on images in some panels that depict Euro-American cultural content (e.g., western-style house, rifle, whiskey keg, horse, etc.). The post-contact era is also apparent in the method used in rendering the engraved images evidenced by the smooth angular lines and chisel strikes produced by metal tools. This paper focuses on narrowing the time frame for these sites based on two additional streams of evidence. First, patterned associations with historic landscape settings tied to the era of western expansion bind the sites together into a coherent whole and set a floor for their oldest probable dates. An example of four sites located in Utah and Arizona illustrates their connection to the last quarter of the nineteenth century and the opening years of the twentieth. Secondly, a study of their imagery supports the proposed dates by revealing a “smoking gun” for the source of many of the individual icons. An example of the methodology used to translate a Western Message Petroglyph panel is described, and a profile of the central author who appears to have acted with a small group of others is suggested in order to aid in the search for this person(s) in the historic record of the American West.

Metal tools of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol: chemical and metallurgical characteristics

In this paper, the chemical composition of tools and ingots of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol region is characterized with identification of main recipes of the alloys using several analytical methods (spectral, X-ray fluorescence, and atomic emission spectrometry analyses carried out in the laboratories of the Institute of Archaeology of the Russian Academy of Sciences and the Institute of Inorganic Chemistry of the Si-berian Branch of the Russian Academy of Sciences). The complexes of the Petrovka Culture of the Sou-thern Trans-Urals have been dated by a set of AMS 14C dates to 19th–18th centuries BCE. Recently introduced in the scientific discourse 27 AMS 14C dates (settlement of Stepnoe and burial grounds of Stepnoe 1, 7 and 25) established an ear-lier interval of the Petrovka series — 2133–1631 BCE and point to the synchroneity of the cultures at the northern periphery of the Sintashta area in the local micro-region of the Southern Trans-Urals. The results of the analytical study of 106 metal tools and 70 ingots of the Petrovka Culture of the Southern Trans-Urals and south of Western Siberia are reported. The statistical processing of the analytical results with plotting correlation diagrams of Sn–As, Sn–Pb, As–Ag, As–Sb, and a frequency distribution histogram for the proportions of Sn allowed casting the metal into 4 metallurgical groups — pure copper and tin, arsenic-tin and arsenic bronzes. The first group subdivided into oxide and sulfidic samples. According to the geochemical peculiarity of the metal from the metal industry centers of Ustie 1, Kulevchi 3 and Shibaevo 1, several sources of oxide-carbonated ores were utilized for copper smelting — malachite and azurite-malachite deposits, while sulfidic chalcocite-covelline ores, and sometimes chalcopyrite-pyrite depositions, were added to the melt as a flux agent. The admixture of sulfides was carried out as an experiment and was not purposeful. Petrovka metallurgists supplied copper to the workshops of the Middle Tobol region — the sites of Ubagan 1, 2, 3 and Kamyshnoe 1, 2. The centers of the Petrovka Culture of the Southern Trans-Urals were domi-nated by the production of pure copper implements, including the metal smelted from the oxidized ore. To a lesser extent, low-alloyed bronze was used — Cu+Sn, Cu+Sn+As and Cu+As, whose feedstock was supplied by the kin-dred tribes of Central and Eastern Kazakhstan in the form of ingots and finished products along the eastern part of the Trans-Eurasian transport corridor of metal trade — over the Turgay trough and further along the extensive river system of the Tobol River and its tributaries. The highest concentration of tools of alloyed bronzes was recorded in the burial grounds of the Middle Tobol, which can be explained from the point of view of the prestige value of such goods and observance of special ceremonial practices.

A Decoration Technique Featured in 18th Century Turkish Bindings: Yekşah

Decoration techniques have changed over time in bookbinding art, as in every branch of art. The 18th century is a period in which the classic style bindings were continued to be made, but at the same time new decoration techniques were tried. Yekşah, one of these techniques, is a decoration technique applied in the form of inlaying/pressing a flat or oval metal iron tool on the motifs embroidered with gold on the binding. This decoration technique takes its name from the metal tool used in the application. This tool, called yekşah iron, is an average of 15-16 cm long and is a flat or oval hand tool. Yekşah decoration technique is applied on bindings applied with brush. ‘Applied with brush binding’ means to embroider the pattern on the leather using gold-ink with a brush. After the pattern is embroidered on the leather with the applied with brush technique, it is started to be processed with yekşah iron tool. Lines are drawn on the motifs with a yekşah iron tool based on the direction of the pattern. The leather is partially pitted during this striping. Yekşah decoration technique joined Turkish bookbinding art at the end of the 17th century and the beginning of the 18th century. Examples continued to be seen in the 19th century. However, the period in which the technique was most frequently used is the 18th century. It is known that yekşah decoration technique is mostly applied by the palace bookbinders and especially on the bindings of the manuscript of high value. As a result of the examinations of the yekşah bindings samples published in the literature of Turkish binding art and found in museums and libraries, it was determined that the yekşah decoration technique was applied on 3 different patterns in Turkish bindings. These; rūmī, lattice (zerbahar/zilbahar) and baroque-rococo patterns. It is seen that the yekşah technique was applied in all parts of the rūmī patterned yekşah binding cover. However, it is most common and most diverse in medallions. The reason for this may be that, as of the 18th century, when yekşah decorations began to be seen, corner pieces were not frequently used on the covers of the binding and the intensity of the decoration was seen on the center-medallions. Three types of medallions were identified in the rūmī patterned yekşah bindings. These are the classical sliced oval form medallion, the rectangular medallion, and the sliced circular form medallion. On the rūmī patterned yekşah bindings, the center-medallion and pendant backgrounds are often painted in burgundy color in order to see the gold of the pattern more clearly. Another type of pattern in which the yekşah decoration technique is applied is the lattice (zerbahar) pattern. Zerbahar pattern is a type of binding decoration seen at the end of the 18th century and especially in the 19th century and was applied to cover the entire surface of the binding. It has been determined that as of the 18th century, yekşah application has been made on realist-style flower or Western-influenced baroque-rococo motifs seen in Turkish bindings. Turkish Rococo is an attractive decoration style in which the surface is completely filled and decorated with C and S curved motifs. Along with curved and round shapes, leaf, flower motifs and flower bouquets are also included in this decoration style. Although yekşah technique is weak in terms of durability, there is an effort to increase the artistic value of the binding, which is often preferred in 18th century bindings. Thanks to this technique, the pattern applied with brush has been made more attractive. This has increased the artistic value of the binding.

Deep Drawing of AISI 304 Blanks with Polymer Punches Produced by Additive Manufacturing: Effects of Process Scalability

Rapid tooling is a methodology which aims to integrate additive manufacturing into the production of tools to be used in casting, forming or machining processes. In forming, rapid tooling is applied in the production of metallic or plastic tools that guarantee good performance in small- and medium-sized batch production. However, most punches tested to date have dimensions measured in millimeters and are therefore unsuitable for typical real-world industrial processes. In this study, the performance of plastic punches with geometries designed for industrial application was investigated. A deep drawing process involving AISI 304 blanks was created for the manufacturing of cups. Experimental and numerical analyses were conducted to measure the quality of the cups produced and the behaviour of the punches involved. The results indicate that when punch dimensions increase, a more precise cup geometry is produced (99% of drawing depth, 98% of cup precision on the fillet radius, and roundness error equal to 0.53%).

Extrusion Additive Manufacturing of PEI Pellets

The simplest, most cost-efficient, and most widespread Additive Manufacturing (AM) technology is Extrusion Additive Manufacturing (EAM). Usually, EAM is performed with filament feedstock, but using pellets instead of filaments yields many benefits, including significantly lower cost and a wider choice of materials. High-performance polymers offer high strength even when produced with AM technique, allowing to produce near-net-shape functional parts. The production of these materials in filament form is still limited and expensive; therefore, in this paper, the possibility of producing AM components with engineering polymers from pellets will be thoroughly investigated. In this work, the effectiveness of a specially designed AM machine for printing high-performance materials in pellet form was tested. The material chosen for the investigation is PEI 1000 which offers outstanding mechanical and thermal properties, giving the possibility to produce with EAM functional components. Sensitivity analyses have been carried out to define a process window in terms of thermal process parameters by observing different response variables. Using the process parameters in the specified range, the additive manufactured material has been mechanically tested, and its microstructure has been investigated, both in dried and undried conditions. Finally, a rapid tool for sheet metal forming has been produced.

Quantifying Edge Sharpness on Stone Flakes: Comparing Mechanical and Micro-Geometric Definitions Across Multiple Raw Materials from Olduvai Gorge (Tanzania)

In line with engineering research focusing on metal tools, techniques to record the attribute of ‘edge sharpness’ on stone tools can include both mechanical and micro-geometric approaches. Mechanically-defined sharpness techniques used in lithic studies are now well established and align with engineering research. The single micro-geometrically-defined technique—tip curvature—is novel relative to approaches used elsewhere, and has not explicitly been tested for its ability to describe the attribute of sharpness. Here, using experimental flakes produced on basalt, chert, and quartzite sourced at Olduvai Gorge (Tanzania), we investigate the relationship between tip curvature and the force and work required to initiate a cut. We do this using controlled cutting tests and analysis of high-resolution microCT scans. Results indicate cutting force and work to display significant dependent relationships with tip curvature, suggesting the latter to be an appropriate metric to record the sharpness of lithic tools. Differences in relationship strength were observed dependent on the measurement scales and edge distances used. Tip curvature is also demonstrated to distinguish between the sharpness of different raw materials. Our data also indicate the predictive relationship between tip curvature and cutting force/work to be one of the strongest yet identified between a stone tool morphological attribute and its cutting performance. Together, this study demonstrates tip curvature to be an appropriate attribute for describing the sharpness of a stone tool’s working edge in diverse raw material scenarios, and that it can be highly predictive of a stone tool’s functional performance.

The Broad-Spectrum Revolution at 50: Increasing dietary diversity reflects the heterogeneity of domesticated landscapes

The area of North-East Poland was in prehistory, and still is today, an area with easy access to amber as a raw material, as is evidenced in part by numerous Late Neolithic (3rd millennium) amber workshops located in the Gulf of Gdańsk and Żuławy Wiślane (Vistula Fens). Given this fact, it is surprising that only a few finished amber products have been recovered from this area. Among them are unique ornaments from the Late Neolithic sites Ząbie 10, Supraśl 3, and Supraśl 6. The preliminary analysis showed that these amber artifacts differ from the products manufactured by local groups located in the territory of modern Poland. The selected artifacts were subjected to in-depth stylistic and technological analysis to identify their provenance, taking also into consideration the type of raw material used in their production by means of FTIR analysis. Stylistic analysis showed that several specimens have analogies amongst the amber beads known from the Bell Beaker phenomenon. However, most of the beads under study are unique, and there are no analogies among any Neolithic ornaments in Europe. In addition, it was found that the specimens from Ząbie 10, Supraśl 3, and Supraśl 6 had perforations drilled with a metal tool, not a flint drill bit, which was previously unheard of in this part of Europe. The FTIR analysis revealed the use of local amber, including its different varieties i.e., succinite, gedano-succinite and gedanite. It also revealed its varying state of preservation. This may be useful for exploring the environmental context in which these artifacts were deposited.

Nanoscale patterning of metallic surfaces with laser patterned tools using a nanoimprinting approach

In this study, we demonstrate that metallic substrates with a nanocrystalline grain size can be structured down to the micro- and nanometre range during a room temperature nanoimprinting process. WC-Co hard metal dies are patterned by Direct Laser Interference Patterning (DLIP), generating an array of separated asperities with a height of 4.7 µm and a spacing of 11.3 µm. Additionally, Laser Induced Periodic Surface Structures (LIPSS) with a spacing of 500 nm are formed as a hierarchical substructure. The patterned dies can be used to deform metallic substrates due to their high hardness. For structure replication, the WC-Co tool is pressed onto a nanocrystalline CuZn30 model alloy at room temperature. The pattern transfer process from the hard metallic tool to the nanocrystalline alloy is discussed in detail: At low contact pressures, the asperities on the tools act as single contact points, leading to the formation of separated dimples with a depth of up to 0.8 µm in the nanocrystalline alloy. At high contact pressures, the tool pattern, including the LIPSS is almost completely transferred to the substrate. The formed asperities protrude out of the surface, with a height to width aspect ratio of 0.4. It is thereby demonstrated, that plastic flow processes during the imprinting of nanocrystalline alloys allow for the replication of the DLIP tool pattern, even down to nano-scaled LIPSS. The imprinted array of surface asperities exhibits hydrophobic properties, due to a combined topographical and chemical influence on the wetting behaviour.

Elemental Composition of Tagar Copper-Bronze Sickle-Shaped Tools

The article features the elemental composition of copper and bronze sickle-shaped tools of the Tagar culture. The structure and composition of metal sickles have been the focus of chemical and spectral quantitative analyses since the 1950s. The paper introduces new data obtained by X-ray fluorescence, energy dispersive, and atomic emission spectral methods. The chemical and chemical-metallurgical features of the alloys add to the external descriptions of the Tagar metal tools. The research objective was to identify the features of Tagar copper-bronze sickles based on the chemical-metallurgical profile of the alloys. The authors also analyzed the effect of the alloy formulations on the morphological and metric characteristics of the tools, compared the bronze formulations with surface patterns, and established the copper ore sources. The study revealed no relationships between the bronze formulations and the morphological and metric indicators. An attempt to search for correlations showed two types of sickle-shaped tools. By measuring the length of the base and the height of the blade, the authors restored the actual sickles and reaping knives. The second type tools came from the Mariinsk-Achinsk foreststeppe. An analysis of the geochemical impurities in high-concentration copper indicated that the ore used in the Tagar tools was similar to that mined in the Glafirinsk and Kharadzhul-Butrakhty mines in the eastern foothills of the Kuznetsk Alatau. The sickle-shaped tools might also have been used to harvest fodder for livestock.

Bone, antler, and tooth objects from the late bronze/early Iron Age urnfields in south-western Poland

Objects made of osseous materials are extremely rare in the urnfield burial contexts dated in SW Poland to the late Bronze and early Iron Age (ca. 1300–550 BCE). That may be the result of the cremation process which made the bone/antler artefacts fragmented and difficult to distinguish from human bones, usually densely packed in ceramic urns. We compare data about 95 specimens from four urnfields (Dunino [2], Jarząbkowice [1], Wicina [1], Sękowice [5]) and one bi-ritual cemetery (Przeczyce [76]). The analysis of micro traces showed that these usually simple and small objects were manufactured both with flint and metal tools. The observation of their colour and surface alterations suggests they were exposed to high temperatures, probably cremated together with the bodies, and then carefully deposited in the urns.

Value Chain Comparison of Additively and Conventionally Manufactured Multi-Cavity Tool Steel Inserts: An Injection Molding Industrial Case Study for High-Volume Production

The development of injection molding tools is an expensive, time-consuming, and resource-intensive process offering little to no flexibility to adapt to variations in product design. Metal additive manufacturing can be used to produce these tools in a cost-effective way. Nevertheless, in an industrial context, effective methods are missing for the selection of the most suitable technology for the given tooling project. This paper presents a method to compare process chains based on additive and conventional subtractive technologies for the manufacturing of metal tooling for injection molding. The comparison is based on a technology focused-performance analysis (TFPA) through computer simulation performed using Tecnomatix Plant Simulation developed by Siemens Digital Industries Software combined with a customized cost–benefit economic analysis tool. The analysis of the technology comparison highlights potential bottlenecks for production, such as the printing phase and the heat treatment. It also gives a deeper understanding of the technology maturity level of conventional milling machines against laser powder bed fusion machines. The result is that the total costs for an insert made by AM and CM are indeed rather similar (the cost difference between the two tooling process chains is lower than 5%). The cost analysis reveals major costs drivers in the production of high-performance molding tools, such as the cutting tools employed for the milling steps and their changeover frequency. The industrial case of a 32-cavity mold insert for plastic injection molding is used to perform the study, develop the analysis, and validate the results.

GRIN pad polishing

AbstractA new concept for CNC polishing pads is given by the gradient index (GRIN) pad polishing tools. Instead of gluing polishing foils as a layer onto metallic tool holders that have the spherical surface to be polished, 3D‐printed GRIN pads are applied directly to the CNC tool axis.

Study of the friction behavior of AlCrN coated micro-textured surfaces

This work proposes a novel method of the formation of micro-textured coated surfaces, which may become an effective means to improve the machining quality and efficiency of metal tools. Micro-texture and AlCrN coating were prepared on the cemented carbide surface by laser and physical vapor deposition, respectively. The friction and wear tester was used to carry out friction tests of cemented carbide pin-titanium alloy disk to analyze its tribological behavior. It was found that the micro-texture coating has a positive effect on the friction properties. The failure mode was determined to be adhesive wear accompanied by oxidation wear, with the failure time of 25 min. Parameter trend analysis demonstrated that laser power and coating thickness are sensitive to friction vibration.

Tools Used in Tagar Rock Art: Findings of an Experimental Traceological Study

We describe the findings of traceological analysis and experiments with bronze and iron tools used by Tagar and Tes artists. The pecking traces these tools leave on the red Devonian sandstone were examined to assess which of them could have been used in rock art production. At the first stage, a preliminary analysis of Tagar petroglyphs was carried out, and metal tools and weapons from the Martyanov Museum of Local History in Minusinsk were examined. Morphologically suitable ones were selected, and experimental tools were made of stone, copper alloys, and low-carbon steel. Experiments were conducted and samples of pecking traces were produced. The final stage of the work consisted of comparing these samples with actual petroglyphs, and use-wear traces on the experimental tools with those on the actual tools. This approach made a direct comparison possible. Among the Tagar and Tes metal tools, those that had likely been used in rock art production were detected. The conclusion was made that no specialized tools designated for that purpose existed at that time in the Minusinsk Basin. Rather, multifunctional tools were used. These were made of tin bronze and low-carbon steel with thermal processing. Such tools first appeared in the region in the Early Iron Age.

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Evaluation of neural network parameters in the prediction of AISI 1050 steel machining performance

ABSTRACT Significant improvement in the design of ANN model has been hindered by the lack of evaluation of alternate model parameters. It is important that in generating a suitable ANN model, the best parameters capable of providing the fastest network and the most accurate test result be employed. In this study, the performance of the NN models based on the most suitable NN parameters such as the number of hidden layer neurons ranging from 2–20, activation functions; sigmoid (logsig), tangent sigmoid (tansig), and the linear (purelin), along with three different training algorithm (LM, SCG, and RP), has been evaluated to accurately predict the response values; metal removal rate (MRR) and tool wear in the turning operation of AISI 1050 steel bar. A great difference was observed in the performance of the activation functions and in the training algorithms. The optimal ANN model prediction, recorded R values of 0.827, 0.920 and 0.983 for the training, validation and testing sub-datasets respectively, while an overall R-value of 0.876 was obtained for the training process, signifying confirmation of the predictive ability of the model. The experiments demonstrate that the identification of the most suitable activation functions can lead to significant performance improvements without actually increasing the number of neurons.

Experimental Investigation and Optimization of Material Removal Rate and Tool Wear in the Machining of Aluminum-Boron Carbide (Al-B4C) Nanocomposite Using EDM Process

Electrical discharge machining (EDM) is a cost-effective unconventional machining method used for machining any composites materials. EDM is based on the thermoelectric energy between the electrode and workpiece. In this work, boron carbide particles of 50 nm (6 wt.%) are reinforced with aluminum 7075 (94 wt.%) prepared using stir casting method. The stir casting process is carried out at speed of 700–800 rev/min. The fabricated aluminum-boron carbide nanometal matrix composites are used as workpiece (anode); copper electrode is used as tool (cathode). This work investigates the influence of EDM process parameters such as current (I), pulse on-time (ton), and tool diameter (d) during machining of Al-B4C composite on metal removal rate (MRR) and tool wear rate (TWR). The design of experimental plan is executed by Taguchi approach, and the responses of each parameter are influenced by analysis of variances (ANOVA). Response table for average value of MRR and TWR shows that the current is the significant parameter affecting MRR and TWR. From this work, it was observed that material removal rate increased with increasing the current, and the tool wear rate decreases.

Comparison of Thermal Behavior of Self-Designed Internally Cooled Cutting Tool for Various Heat Transfer Fluids-Statistic and Computational Fluid Dynamics Approach

Abstract Compared with dry machining, using traditional cutting fluids has some weaknesses, such as environmental pollution, high machining costs, and harmful effects on human health. Internally cooled cutting tools (ICCTs) have been promising, sustainable, health-friendly, and green technologies for turning applications. However, the effects of different types of internal coolant fluids on insert tip temperature (Ttip) have not been investigated for ICCTs. The machining quality of metallic materials and tool life can improve with effective cooling. This study investigates the internal cooling performance of a self-designed internally cooled smart cutting tool (ICSCT) by comparing different heat transfer fluids. Therefore, a conjugate heat transfer (CHT) model was set for a self-designed ICSCT. The CHT simulation was experimentally confirmed using pure water (…developed by Ozturk, E., Yildizli, K., and Saglam, F., 2021, “Investigation on an Innovative Internally Cooled Smart Cutting Tool With the Built-In Cooling-Control System,” Arab. J. Sci. Eng., 46(3), pp. 2397–2411). After that, the effects of flow velocity (Vf) and the inlet temperature of the coolant fluid (Tinlet) alongside different types of glycol-based heat transfer fluids (including pure water) on Ttip were statistically evaluated by the Taguchi method and analysis of the variance (ANOVA). It was found that the most influential factor was the Tinlet at a contribution ratio level of 88.32%. Additionally, according to statistics, Vf and the type of heat transfer fluid were significant. Hence, since no external coolant is used, the designed smart tool can be considered environmentally friendly and health-friendly. In conclusion, glycol-based fluids can be a better choice for internally cooled tool designs owing to their superior features, e.g., corrosion prevention, nontoxicity, and stable heat transfer capability at lower temperatures compared to pure water, although pure water has better thermal properties than the glycol-based fluids (Dynalene Heat Transfer Fluids Technical Datasheets, Cited March 31, 2020).

Provenance studies on Late Neolithic amber ornaments from North-East Poland

The area of North-East Poland was in prehistory, and still is today, an area with easy access to amber as a raw material, as is evidenced in part by numerous Late Neolithic (3rd millennium) amber workshops located in the Gulf of Gdańsk and Żuławy Wiślane (Vistula Fens). Given this fact, it is surprising that only a few finished amber products have been recovered from this area. Among them are unique ornaments from the Late Neolithic sites Ząbie 10, Supraśl 3, and Supraśl 6. The preliminary analysis showed that these amber artifacts differ from the products manufactured by local groups located in the territory of modern Poland. The selected artifacts were subjected to in-depth stylistic and technological analysis to identify their provenance, taking also into consideration the type of raw material used in their production by means of FTIR analysis. Stylistic analysis showed that several specimens have analogies amongst the amber beads known from the Bell Beaker phenomenon. However, most of the beads under study are unique, and there are no analogies among any Neolithic ornaments in Europe. In addition, it was found that the specimens from Ząbie 10, Supraśl 3, and Supraśl 6 had perforations drilled with a metal tool, not a flint drill bit, which was previously unheard of in this part of Europe. The FTIR analysis revealed the use of local amber, including its different varieties i.e., succinite, gedano-succinite and gedanite. It also revealed its varying state of preservation. This may be useful for exploring the environmental context in which these artifacts were deposited.

Insight into the carbonaceous fraction of three cultural layers of different age from the area of Verona (NE Italy)

Cultural layers are deposits resulting from settlement and human activity on natural soil in the past. Materials from past domestic activities that become buried into the soil can be used to reconstruct human impact in a specific area in the past. For instance, humans have used fire for millennia, and charcoal in soils and sediments is applied as evidence of anthropic activity. In this context, assessing the abundance and degradation level of charcoal fragments can clarify anthropic activities in cultural deposits. In European towns, cultural layers with similar characteristics, have been defined as urban “Dark Earth” (UDE) but their age, formation and composition often differ significantly across sites.This study examined three archaeological sites in Verona, Italy, where UDE layers with similar characteristics have been identified. The primary aim of this research is to understand the anthropogenic influence on the development of UDE layers, by characterizing their geochemistry and the carbonaceous materials. To pursue this goal, we provide a micromorphological description of the sites, evaluate UDE features and the abundance of charred material andcharacterize the amorphous/crystalline degreethrough µ-Raman spectroscopy. Bulk material was described in terms of amounts of total organic carbon (TOC), recalcitrant organic carbon (ROC), total inorganic carbon (TIC), and trace element concentration. Radiocarbon dating of charred and humin fractions was performed to clarify the dynamics underlying UDE origin. We investigate the relationship between the different variables analyzed in the UDE layers at each site. Results show that a diverse array of human activities including metal tool and/or ceramic manufacturing were related to the formation of UDE layers. The investigation of carbonaceous fractions highlight differences in soil organic carbon and charred material, both of which are correlated with human influence.