The Reconstruction of a Bronze Battle Axe and Comparison of Inflicted

Journal of Imaging

Article The Reconstruction of a Bronze Battle Axe and Comparison of Inﬂicted Damage Injuries Using Neutron Tomography, Manufacturing Modeling, and X-ray Microtomography Data

Maria Mednikova 1,* , Irina Saprykina 1,2, Sergey Kichanov 2 and Denis Kozlenko 2 1 Department of Theory and Methods, Institute of Archaeology RAS, 117036 Moscow, Russia; [email protected] 2 Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia; [email protected] (S.K.); [email protected] (D.K.) * Correspondence: [email protected]; Tel.: +7-916-714-4625

Received: 14 April 2020; Accepted: 3 June 2020; Published: 8 June 2020

Abstract: A massive bronze battle axe from the Abashevo archaeological culture was studied using neutron tomography and manufacturing modeling from production molds. Detailed structural data were acquired to simulate and model possible injuries and wounds caused by this battle axe. We report the results of neutron tomography experiments on the bronze battle axe, as well as manufactured plastic and virtual models of the traumas obtained at different strike angles from this axe. The reconstructed 3D models of the battle axe, plastic imprint model, and real wound and trauma traces on the bones of the ancient peoples of the Abashevo archaeological culture were obtained. Skulls with traces of injuries originate from archaeological excavations of the Pepkino burial mound of the Abashevo culture in the Volga region. The reconstruction and identification of the injuries and type of weapon on the restored skulls were performed. The complementary use of 3D visualization methods allowed us to make some assumptions on the cause of death of the people of the Abashevo culture and possible intra-tribal conflict in this cultural society. The obtained structural and anthropological data can be used to develop new concepts and methods for the archaeology of conflict.

Keywords: cultural heritage; Bronze Age; 3D model reconstruction; weapon injuries reconstruction; neutron tomography; X-ray microtomography

1. Introduction In recent years, more attention from archaeologists and other history-related scientists has been focused on comprehensive studies of the great number of cultural heritage items using natural science methods. The ever-growing number of scientific research methods is being used to study the physical and chemical properties of ancient coins [1,2], metal weapons [3,4], and stone, glass, and ceramic archaeological objects [5]. The obtained results are intended to be used to expand our knowledge about ancient production technologies, the origins of ore mining, the degree of preservation, and corrosion and crack penetration [6,7]. The uniqueness and great value of museum archaeological items require modern, innovative approaches to their study. Besides this, nondestructive structural imaging methods such as neutron and X-ray tomography are advantageous [8,9]. In our work, we want to present not only the capabilities of structural imaging methods [7–10] but also bioarchaeological-related methods of historical reconstruction of the identification processes of damage caused by metal weapons of the Bronze Age based on human remains. Our joint studies are dictated by the requests of one scientific direction in archaeometry science, namely, conflict

J. Imaging 2020, 6, 45; doi:10.3390/jimaging6060045 www.mdpi.com/journal/jimaging J. Imaging 2020, 6, 45 2 of 9 archaeology [11–13]. There are many archaeological finds connected to the manifestations and determinations of great violence between individual humans and cultural groups in the past [11,13]. The reasons, evolution, and passing of conflicts can be derived from joint research by physicists and anthropologists. Studies of ancient weapons and the remains of peoples can be used to recover the battle opportunities and experiences of the distant past. Modern osteology techniques and methods are used for reconstruction of the wounds, injuries, and traumas of ancient warriors or civilians. In the frame of the historical theory of conflicts, Bronze Age metal battle axes are indicators of a great degree of ancient society militarization [11]. For these joint studies, we chose a bronze axe found on the forest-steppe territory of the area of the Abashevo archaeological culture, dated from the end of the 3rd millennium B.C. This culture is characterized by developed livestock, agricultural farming, and bronze metalworking, in which it has several points of linkage with the Eurasian metallurgical province [14,15]. The axe was excavated in the Malo-Kizilsky settlement (territory of Eastern Abashevo) in the modern Ural region of the Russian Federation. On the other hand, one of the famous archaeological sites of the Abashevo culture is the Pepkino burial mound [16,17] in the Volga region, Russia. This collective burial site contains the remains of 27 persons bearing traces of violent deaths. The nature of the injuries indicates that the enemies used bows in the first wave, and then they attacked with battle axes in close combat. Those Abashevo men from the Pepkino burial who did not fall from arrows immediately, fought hard. Their skulls show many traumas from strike weapons [17]. The archaeology of conflict declares this tragic situation a result of the political and social situations of the tribes of the Abashevo archaeological cultures or their interaction with neighboring cultures. In addition to the remains of bones in the Pepkino burial, utensils, jewelry, bone amulets, and, particularly interestingly, production molds for bronze axes similar to the above-mentioned were found. In order to expand our knowledge in the archaeology of conflict, the cultural origin of the found bronze axe, the technology of its manufacture, and the relation of this axe to the received lethal wounds on the skulls of the remains of people from the Pepkino burial mound were studied. In our research, modern imaging methods like neutron and X-ray microtomography were utilized. Manufacturing modeling based on the found molds was performed. We believe that the presented bioarchaeological results of our joint research can form a basis for some conclusions in the archaeology of conflict about ancient Abashevo cultural evolution and its cross-cultural interactions.

2. Materials and Methods The bronze battle axes of the Abashevo archaeological culture are heavy and lethal weapons. For our studies, we selected a real bronze battle axe of the Abashevo culture from the ancient settlement Malo-Kizilsky, Russian Federation [18]. This archaeological site was discovered in 1948 by archaeologist K.V. Salnikov [14]. The settlement consists of several huts, burials, and skeletal remains. It is assumed that this settlement was destroyed and burned down as a result of an external attack [17]. The weight of the studied axe is 953 g. Its blade length is 209 mm, the blade width is 50 mm, and the width of the hitting edge is about 6 mm and 0.3 mm at the sharp part (Figure1). This axe could inflict deep, lethal head traumas, including penetrating wounds. The bone remains with similar wounds were collected from the Pepkino burial mound in the Volga-Kama archaeological area. Based on visual observations, the majority of the human skulls there have traumatic wounds inflicted by a battle axe [17]. Both archaeological sites (Malo-Kizilsky and Pepkino) belong to the same Abashevo culture, and the finds correspond to approximately the same period. The connection between the shape and structure of the real bronze axe and the inflicted wounds on the bones is the aim of the presented studies. X-ray microtomography of the bone samples from Pepkino was performed using FEI HELISCAN. X-ray tomography with an accelerating voltage of 20–160 kV can provide single projections, circular or spiral tomography of samples with resolution 0.8 µm, and tomography with a double spiral trajectory, or with an iterative trajectory. FEI HELISCAN provides an opportunity to perform running tomography of samples with length/diameter up to 8 cm, reconstruction of tomography data, and visualization of 2D virtual slices. J. Imaging 2020, 6, x FOR PEER REVIEW 3 of 9

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Figure 1. A photo of the bronze axe from the Malo-Kizilsky settlement of the Abashevo culture. A scale line of 30 mm is presented. Figure 1. A photo of the bronze axe from the Malo-Kizilsky settlement of the Abashevo culture. A Modelingscale line of of 30 themm bronze is presented. axe hitting edge was performed by an imprint of plasticine materials heated up to 110 ◦C based on the tomography reconstruction model. MicroCT scanning of the obtainedX-ray plasticine microtomography model was of performed. the bone Bioarchaeologicalsamples from Pepkino comparisons was ofperformed the axemodel using withFEI theHELISCAN. three-dimensional X-ray tomograph (3D) datay ofwith cranial an traumasaccelerating were voltage performed. of 20– Thermo160 kV Scientificcan provide™ PerGeos single Softwareprojections, (Systems circular for or Microscopy spiral tomography and Analysis, of samples Moscow, with Russia) resolution was used0.8 μm, for and the segmentationtomography with and visualizationa double spiral of trajectory, virtual data. or with an iterative trajectory. FEI HELISCAN provides an opportunity to performThe neutronrunning tomography tomography experiments of samples were with performed length/diameter at a neutron up radiographyto 8 cm, reconstruction and tomography of facilitytomography [19,20 data,], with and the visualization subject placed of on2D beamlinevirtual slices. 14 of the IBR-2 high-flux pulsed reactor at JINR, Dubna.Modeling The characteristic of the bronze parameter axe hitting L/ Dedge was was 200 performed in the neutron by an experiments. imprint of plasticine A set of materials neutron radiographyheated up to images 110 °C was based collected on the by tomography a detector systemreconstruction based on model a high-sensitivity. MicroCT scanning camera withof the a 6 HAMAMATSUobtained plasticine S12101 model CCD was chip. performed The LiF. /BZnS(Cu)ioarchaeological scintillation comparisons screen manufactured of the axe model by RC with TRITEC the Ltdthree (Teufen,-dimension Switzerland)al (3D) wasdata usedof cranial for converting traumas neutron were radiationperformed. into Thermo visible light.Scientific™ The field PerGeos of view of the detector is 200 mm 200 mm. The tomography experiments were performed with a rotation Software (Systems for Micros× copy and Analysis, Moscow, Russia) was used for the segmentation and stepvisualization of 0.5◦; the of totalvirtual number data. of measured radiography projections was 360. The exposure time for one projectionThe wasneutron 20 s. Thetomography imaging data experiments were corrected were by performed the camera darkat a current neutron image radiography and normalized and totomography the image offacility the incident [19,20] neutron, with the beam subject using placed ImageJ on software beamline [21 ].14 The of tomographicthe IBR-2 high reconstruction-flux pulsed wasreactor performed at JINR, byDubna utilizing. The SYRMEP characteristic Tomo parameter Project (STP) L/D software was 200 [in22 the]. Finally, neutron a dataexperiments. set containing A set theof neutron volume radiography distribution ofimages 3D pixels was (voxels)collected was by a reconstructed. detector system The based size ofon one a high voxel-sensitivity in our studies camera is 52withµm a HAMAMATSU52 µm 52 µm. S12101 The 3D CCD volume chip. dataThe 6 ofLiF/ZnS(Cu) voxels are thescintillation essence ofscreen the spatial manufactured distribution by RC of × × valuesTRITEC of Ltd the ( neutronTeufen, attenuationSwitzerland) coe wasfficients used for inside converting the sample neutron volume. radiation Attenuation into visible of the light. neutron The beamfield of corresponds view of the withdetector scattering is 200 mm and × absorption 200 mm. The losses tomography inside the experiments material [8]. were VGStudio performed MAX with 2.2 softwarea rotation from step Volume of 0.5º; Graphicsthe total number (Heidelberg, of measured Germany) radiography was used for projections the visualization was 360. and The analysis exposure of reconstructedtime for one projection 3D data. was 20 s. The imaging data were corrected by the camera dark current image and normalized to the image of the incident neutron beam using ImageJ software [21]. The 3. Results and Discussion tomographic reconstruction was performed by utilizing SYRMEP Tomo Project (STP) software [22]. 3.1.Finally, Neutron a data Tomography set containing of the Bronzethe volume Battle Axedistribution of 3D pixels (voxels) was reconstructed. The size of one voxel in our studies is 52 µm × 52 µm × 52 µm. The 3D volume data of voxels are the essenceThe of structural the spatial model distribution and 3D spatial of values distribution of the neutron of internal attenuation components coefficients of the bronze inside axe the from sample the Malo-Kizilskyvolume. Attenuation settlement of the were neutron determined beam usingcorresponds a neutron with tomography scattering method.and absorption A set of losse 360 neutrons inside radiographicthe material images[8]. VGStudio for diff erentMAX angular 2.2 software positions from of theVolume metal Graphics axe relative (Heidelberg, to the beam Germany) direction was usedused for 3Dthe tomographicvisualization reconstructionand analysis of ofreconstructed the axe’s inner 3D structure,data. its casting defects, and hidden traces (Figure2)[7,8]. The reconstructed 3D model of the bronze battle axe is presented in Figure2a. The obtained shape of the axe model indicates that it belongs to the sleeve lop-sided type 3 of axes of the Kamsky region [23]. Interestingly, the molds from the Pepkino burial mound correspond to the same type of battle axe.

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3. Results and Discussion

3.1. Neutron Tomography of the Bronze Battle Axe The structural model and 3D spatial distribution of internal components of the bronze axe from the Malo-Kizilsky settlement were determined using a neutron tomography method. A set of 360 neutron radiographic images for different angular positions of the metal axe relative to the beam directionJ. Imaging 2020 was, 6 ,used 45 for 3D tomographic reconstruction of the axe’s inner structure, its casting defects,4 of 9 and hidden traces (Figure 2) [7,8].

true blade of axe under the patina

internal cavities

0 30mm FigureFigure 2. 2. (a()a 3D) 3D model model of ofthe the bronze bronze axe axe after after tomographic tomographic reconstruction reconstruction from from neutron neutron data. data. (b) L(bongitudinal) Longitudinal virtual virtual slice slice of the of the 3D 3D model model of ofthe the bronze bronze battle battle axe. axe. The The inner inner voids voids and and cavities cavities are are visible.visible. The The bottom bottom large large void void is is a a manufacturing manufacturing defect defect.. The The rainbow rainbow-like-like coloring coloring shows shows the the neutron neutron absorptionabsorption degree fromfrom lowlow (blue)(blue) to to high high (red). (red). ( c()с Transparent) Transparent virtual virtual model model of theof the bronze bronze battle battle axe axewith with contrasting contrasting internal internal voids. voids.

TheNeutron reconstructed absorption 3D inside model the of axe the volume bronze is battle mostly axe heterogeneous. is presented in Some Figure near-surface 2a. The obt regionsained shapecorresponding of the axe to model areas ofindicates higher neutronthat it belongs attenuation to the coe sleevefficient lop were-sided detected. type 3 of We axes suggest of the that Kamsky these regionare some [23 patina]. Interestingly, areas [24 ].the These molds areas from were the virtuallyPepkino separatedburial mound and cutcorrespond from the to total the reconstructedsame type of battlevolume axe. of the battle axe to improve its model for future calculations. Several hollows and cavities on the surfaceNeutron of absorption the bronze inside axe are the visible axe vol (Figureume 2isb,c). mostly This heterogeneous. type of defect mostSome likely near-surface corresponds regions to correspondingan effect of insu toffi areascient of filling higher of neutron molds or attenuation some overheating coefficient of were the metal detected. during We casting. suggest Inthat general, these arethe some data obtainedpatina areas indicate [24]. thatThese the areas structure were virtually of the internal separated volume and of cut the from axe the is quite total dense,reconstruct withed no volumepronounced of the porosity, battle axe except to improve for large its model casting for defects future (seecalculations. below). Several The volume hollows of and the bronzecavities axeon 3 theconsists surface of 137,774,522of the bronze voxels axe are or 19,372.2(1)visible (Figure mm 2b,c), while. This the type cavity of defect volume most forms likely 1,687,101 correspond voxelss to or 3 an237.2(1) effect mmof insufficient, 1.2(2)% of filling the total of molds volume. or some overheating of the metal during casting. In general, the dataWe obtained theindicate chemical thatcomposition the structure of of the the metal internal of this volume axe using of the an axe EDAX is quite Orbis dense, PC Micro-XRF with no pronouncedAnalyzer spectrometer. porosity, except The studiedfor large bronze casting battle defects axe (see from below). the Malo-Kizilsky The volume settlementof the bronze is made axe consistsof arsenic of bronze,137,774, which522 voxels is a nativeor 19,372.2(1) alloy of mm the3 Tash-Kazgan, while the cavity Deposit volume with forms pale ores1,687 [,23101]. Thisvoxels type or 237.2(1)of bronze mm alloy3, 1.2(2)% is characterized of the total byvolume. quality casting and expanded plasticity of copper. As a result, cold forging of arsenic bronzes and a complex slope of the axe dramatically increase the durability of the weapon. However, local arsenic saturation of more than 8% leads to embrittlement of the bronze product. We can assume that this is the reason for the formation of cavities and cracks inside the volume of the studied axe. Also, these cavities can be the result of the release or venting of associated gas during the casting process. This type of defect appears when the melting technology is not strictly enforced: the metal is not deoxidized enough and the molds are not calcined enough. J. Imaging 2020, 6, x FOR PEER REVIEW 5 of 9

We obtained the chemical composition of the metal of this axe using an EDAX Orbis PC Micro- XRF Analyzer spectrometer. The studied bronze battle axe from the Malo-Kizilsky settlement is made of arsenic bronze, which is a native alloy of the Tash-Kazgan Deposit with pale ores [23]. This type of bronze alloy is characterized by quality casting and expanded plasticity of copper. As a result, cold forging of arsenic bronzes and a complex slope of the axe dramatically increase the durability of the weapon. However, local arsenic saturation of more than 8% leads to embrittlement of the bronze product. We can assume that this is the reason for the formation of cavities and cracks inside the volume of the studied axe. Also, these cavities can be the result of the release or venting of associated gas during the casting process. This type of defect appears when the melting technology is not strictly enforced: the metal is not deoxidized enough and the molds are not calcined enough. J. Imaging 2020, 6, 45 5 of 9 3.2. Bioarchaeological Studies of the Bone Remains Using X-ray Microtomography

3.2. BioarchaeologicalPrevious bioarchaeolog Studies ofical the Bonestudies Remains of the Usingwounds X-ray and Microtomography injuries on bone remains have sufficient scientific content [12,25,26]. As an experimental example, the artificial skin–skull–brain model was Previous bioarchaeological studies of the wounds and injuries on bone remains have sufficient used for the modeling of blunt force traumas from the European Neolithic osteological record [27]. A scientific content [12,25,26]. As an experimental example, the artificial skin–skull–brain model was used replica of a Neolithic wooden club was able to produce the wounds in synthetic skulls with for the modeling of blunt force traumas from the European Neolithic osteological record [27]. A replica remarkable comparisons to Neolithic skeletal remains from an archaeological site in Austria. Fracture of a Neolithic wooden club was able to produce the wounds in synthetic skulls with remarkable formation from blunt force trauma to the skull is dependent on its biomechanical properties. Cranial comparisons to Neolithic skeletal remains from an archaeological site in Austria. Fracture formation bone consists of three layers. The outer and inner layers are compact, high-density cortical bone, from blunt force trauma to the skull is dependent on its biomechanical properties. Cranial bone while the intermediate layer is a low-density, irregularly porous bone structure. Studying fractures, consists of three layers. The outer and inner layers are compact, high-density cortical bone, while the we need to produce lesions on specimens of cranial bone. There are several types of fractures in the intermediate layer is a low-density, irregularly porous bone structure. Studying fractures, we need to case of blunt force trauma, such as linear fractures, produced by a low-velocity force, or depressed produce lesions on specimens of cranial bone. There are several types of fractures in the case of blunt fractures with primary, secondary, or even tertiary changes [27]. Speaking of weapon injuries, one force trauma, such as linear fractures, produced by a low-velocity force, or depressed fractures with should differentiate between blunt force trauma that produces crushing and is indicative of club-like primary, secondary, or even tertiary changes [27]. Speaking of weapon injuries, one should differentiate weapons and sharp force trauma that is produced by a bladed weapon. Bioarchaeologists also between blunt force trauma that produces crushing and is indicative of club-like weapons and sharp encounter penetrating wounds from projectiles or pointed weapons. Both linear fractures and force trauma that is produced by a bladed weapon. Bioarchaeologists also encounter penetrating comminuted fractures of the cranium are caused by impact with wider objects, whereas depressed wounds from projectiles or pointed weapons. Both linear fractures and comminuted fractures of the and penetrating fractures are a result of narrow objects [28,29] (the last could be a case of bronze cranium are caused by impact with wider objects, whereas depressed and penetrating fractures are a battle axe use). result of narrow objects [28,29] (the last could be a case of bronze battle axe use). The ancient molds of the bronze battle axe were found in the Pepkino burial archaeological site. The ancient molds of the bronze battle axe were found in the Pepkino burial archaeological Experimental imprints of several hits by the same battle axe from the Malo-Kysilski site were made site. Experimental imprints of several hits by the same battle axe from the Malo-Kysilski site were using plasticine. The obtained plastic model was converted into a 3D virtual copy using X-ray made using plasticine. The obtained plastic model was converted into a 3D virtual copy using X-ray microtomography methods (Figure 3). The shapes and cutting angles of the hitting edge of the microtomography methods (Figure3). The shapes and cutting angles of the hitting edge of the recovered model of the bronze battle axe were used for modeling of the caused traumas on the bones. recovered model of the bronze battle axe were used for modeling of the caused traumas on the bones. This model can also be used to identify shallow or superficial wounds that are characteristic of This model can also be used to identify shallow or superficial wounds that are characteristic of fighting fighting or defending warriors. or defending warriors. 6 5

c m m m

3 cm

Figure 3. Virtual reconstructed model: (a) 3D virtual model of hit tracks in the plasticine obtained from the battle axe from the Malo-Kizylski site, resolution 180; (b) virtual transverse slice of the battle axe imprint; (c) virtual longitudinal slice of the battle axe imprint, resolution 70 µm.

Human skeletal remains from excavations of the Pepkino burial mound bear many traumatic wounds on the skulls and postcranial bones (Figure4). The primary hypothesis is that young men of the Abashevo culture fell at the hands of enemies, which were the representatives of another tribe or culture [14,16]. After their discovery in the XX century, the skulls of killed people of the Abashevo culture were restored using anthropological paste, including beeswax. The inner and external surfaces of skulls, especially damaged, were covered by these materials. These restored surfaces were tested using X-ray microtomography in order to identify hidden defects. The beeswax layers were virtually separated and removed from the model. J. Imaging 2020, 6, x FOR PEER REVIEW 6 of 9

Human skeletal remains from excavations of the Pepkino burial mound bear many traumatic wounds on the skulls and postcranial bones (Figure 4). The primary hypothesis is that young men of the Abashevo culture fell at the hands of enemies, which were the representatives of another tribe or culture [14,16]. After their discovery in the XX century, the skulls of killed people of the Abashevo culture were restored using anthropological paste, including beeswax. The inner and external J. Imagingsurfaces2020, 6of, 45 skulls, especially damaged, were covered by these materials. These restored surfaces were 6 of 9 tested using X-ray microtomography in order to identify hidden defects. The beeswax layers were virtually separated and removed from the model.

FigureFigure 4. Virtual 4. Virtual 3D 3D reconstruction reconstruction of of a a male male skullskull from the the Pepkino Pepkino mound mound with with damage damage from from battle battle axes.axes. The The yellow yellow layers layers are are virtual virtual tracks tracks of of thethe beeswaxbeeswax material. material.

We identiﬁedWe identified solid solid and and multiple multiple oval-shaped oval-shaped wounds wounds caused caused by by battle battle axes. axes. The The majority majority of of them, representedthem, represented by holes surrounded by holes surrounded by radiating by radiating fractures, fractures were, associatedwere associated with with a high-velocity a high-velocity hit by a heavyhit weapon by a heavy and weapon could not and indicate could no thet indicate type of the battle type axeof battle directly. axe directly. However, However, a superﬁcial a superficial oval defect oval defect in the lower part of the left parietal bone was visible after X-ray microtomography in the lower part of the left parietal bone was visible after X-ray microtomography reconstruction reconstruction (Figure 5). (Figure5). J. Imaging 2020, 6, x FOR PEER REVIEW 7 of 9

Figure 5. The part of the 3D model of the skull with external damage (arrow)(arrow) virtually cleaned of restoring beeswax.beeswax. TheThe yellowyellow layerslayers areare the the virtual virtual remains remains of of the the beeswax beeswax material. material. The The resolution resolution is 80is 80µm. µm.

A simple explanation for obtaining such injuries is the conclusion that the victim stood face to face with their assaulter and tried to back away from the battle axe, but fell and received other lethal wounds. The superficial trauma by the battle axe as well as serious damage to a bone structure and deep cracks in the skull are visible in the upper part of the model. The virtual slice of the cranial damage reflects the triangle-shaped hitting edge of the bronze battle axe (Figure 6). The shape of the wound looks similar to the shape of the reconstructed plasticine model where the edge hit angle was close to 45° (Figure 3b).

Figure 6. Vertical transverse slice of the cranial vault reflecting the shape of the weapon. The resolution is 190 µm.

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J. ImagingFigure2020 5., 6 The, 45 part of the 3D model of the skull with external damage (arrow) virtually cleaned of 7 of 9 restoring beeswax. The yellow layers are the virtual remains of the beeswax material. The resolution is 80 µm. A simple explanation for obtaining such injuries is the conclusion that the victim stood face to faceA with simple their explanation assaulter and for tried obtaining to back such away inju fromries theis the battle conclusion axe, but that fell and the receivedvictim stood other face lethal to facewounds. with their The superﬁcialassaulter and trauma tried by to theback battle away axe from as wellthe battle as serious axe, but damage fell and to received a bone structure other lethal and wounds.deep cracks The insuperficial the skull trauma are visible by the in thebattle upper axe as part well of as the serious model. damage The virtual to a bone slice structure of the cranial and deepdamage cracks reﬂects in the the skull triangle-shaped are visible in hitting the upper edge ofpart the of bronze the model battle. axeThe (Figurevirtual6 ).slice The of shape the cranial of the damagewound looksreflects similar the triangle to the shape-shaped of hitting the reconstructed edge of theplasticine bronze battle model axe where (Figure the 6). edge The hitshape angle of wasthe woundclose to looks 45◦ (Figure similar3b). to the shape of the reconstructed plasticine model where the edge hit angle was close to 45° (Figure 3b).

FigureFigure 6. VerticalVertical transverse transverse slice slice of theof cranialthe cranial vault vault reﬂecting reflecting the shape the ofshape the weapon. of the Theweapon. resolution The risesolution 190 µm. is 190 µm.

4. Conclusions The modern methods neutron and X-ray microtomography for the 3D visualization and modeling of cultural heritage items were used to reconstruct the model of an ancient bronze battle axe and bone remains with wounds and damage received by people of the Abashevo culture. The production modeling of the battle axe shape from plasticine, together with neutron tomography data, allowed us to identify the bronze axe, determine its type, and obtain bioarchaeological parameters, such as the angles of the blade’s edge and upper hitting part. The obtained 3D data were used to compare injuries and wounds on human skulls with the specifics of the battle axe shape. Microtomography of skulls allowed us to divide the wounds into penetrating and siding wound groups. It is most important that the 3D data of the axe and skulls allowed us to look for conformity of the injuries and the structural models of the battle axes. The comparison of the real bronze axe with the model obtained from molds indicates their complete identity and the belonging of these axes from different archaeological sites of the Abashevo culture to the same cultural group. This conclusion may indicate intra-cultural conflict among the Abashevo people. As a final note, the presented results of quite diverse imaging methods indicate a new direction in the archaeology of conflicts and the applicability of 3D modeling methods to identify both weapons technologies and the specifics of the use of these weapons to injure humans.

Author Contributions: Conceptualization, M.M. and I.S.; methodology, M.M.; anthropological studies, M.M.; archaeological background, I.S.; neutron experiments, S.K. and D.K.; X-ray microtomography, modeling, M.M.; validation, I.S., S.K. and D.K.; writing—original draft preparation, M.M. and I.S.; writing—review and editing, S.K., I.S., M.M.; visualization, M.M., D.K. All authors have read and agreed to the published version of the manuscript. J. Imaging 2020, 6, 45 8 of 9

Funding: This research received no external funding. Acknowledgments: The authors express deep thanks to S. Kuzminykh for the opportunity to study the Abashevo battle axe. Maria Mednikova is very grateful to Julia Troizkaya (Systems for Microscopy and Analysis, Moscow) for help in virtual imaging. Conﬂicts of Interest: The authors declare no conﬂict of interest.

References

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