Archaeological Samples Research Articles

Archaeological and modern whitemouth croaker fish (Micropogonias furnieri) of southeastern Brazil: A geochemical proxy for environmental preference

In this study, laser ablation–inductively coupled plasma–mass spectrometry was used to characterize the growth patterns of otolith of Micropogonias furnieri from southeastern Brazil under the influence of coastal marine upwelling. Archaeological fish sagittae otoliths of M. furnieri recovered from Brazilian shell mounds (5820‒4980 cal BP) were analysed and compared with those of modern specimens. Otolith Sr/Ca analysis indicated that off southeastern Brazil, M. furnieri shifted from freshwater/brackish in archaeological specimens to brackish/marine in modern times. Regular core-to-edge Sr/Ca oscillations suggest that both modern and archaeological M. furnieri are resident estuarine fish that also use the marine waters adjacent to the coastal zone. Based on analyses of a wide range of otolith edge Sr/Ca values measured in archaeological samples, pre-colonial fishing activities in the coastal regions of Guanabara Bay occurred throughout the year. This study reinforces the importance of M. furnieri as a precolonial fishing resource in this area and demonstrates a shift in fishing practices, where smaller fish are targetted within the bay and larger fish are caught beyond the bay. These data may also be indicative of a shift in the life cycle of this species, possibly caused by the overfishing of this important resource and significant increase in human activities in protected coastal waters in modern times.

Differentiating present-day from ancient bones by vibrational spectroscopy upon acetic acid treatment

Acetic acid treatment for an accurate differentiation between ancient and recent human bones was assessed using Raman and FTIR-ATR spectroscopies. Each set of skeletal samples was analysed by these techniques, prior and after chemical washing, in order to determine the variations in bone´s chemical composition and crystallinity. Bone samples were collected from several independent sources: recent bones burned under controlled experimental conditions or cremated, and archaeological (XVII century and Iron Age). The effect of acetic acid, expected to impact mostly on carbonates, was clearly evidenced in the spectra of all samples, particularly in FTIR-ATR, mainly through the bands typical of A- and B-carbonates. Furthermore, as seen for crematoria and archaeological samples, acetic acid was found to remove contaminants such as calcium hydroxide. Overall, acetic acid treatment can be an effective method for removing carbonates (exogenous but possibly also endogenous) and external contaminants from bone. However, these effects are dependent on the skeletal conditions (e.g. post-mortem interval and burning settings). In addition, this chemical washing was shown to be insufficient for an unequivocal discrimination between recent and archaeological skeletal remains. Based on the measured IR indexes, only cremated bones could be clearly distinguished.

Tracing microbial communities associated with archaeological human samples in Latvia, 7-11th centuries AD.

In the grave environment, microorganisms are major ecological participants in the successional decomposition of vertebrates and could infiltrate the skeleton/skeletal material during taphonomic processes. The diversity of archaeological skeleton-associated microbial assemblages and the impact of various factors are poorly understood. This study aimed to evaluate the taxonomic microbial composition of archaeological human bone and teeth samples from the 7th to 11th centuries AD from two burial sites in Latvia. Samples were analysed by a shotgun metagenomics-based approach. The results showed a strong presence of the environmental DNA in the samples, and variability in microbial community structure between individual samples. Differences in microbial composition were observed between bone and tooth samples, as well as between different burial sites. Furthermore, the presence of endogenous ancient DNA (aDNA) in tooth samples was detected. Overall, compositions of microbial communities associated with archaeological human remains in Latvia dated 7-11th century AD were influenced by the sample type and burial location. These findings indicate that, while the content of historical DNA in archaeological samples is low, the comparison of archaeological skeleton-associated microbial assemblages across time and space, along with aDNA damage profile analysis, is important and could help to reveal putative ancient microorganisms.

GC–MS analysis of soil faecal biomarkers uncovers mammalian species and the economic management of the archeological site "Le Colombare di Negrar"

The identification of the mammalian species based on faecal sediments in modern and ancient environments is the aim of the research of archaeologists, forensic scientists and ecologists. Here, we set up and validated an optimized gas chromatography-mass spectrometry (GC–MS) method, characterized by a time-saving sample preparation protocol, for the simultaneous analysis of faecal biomarkers (6 sterols/stanols and 5 bile acids) in 14 soil samples from the archaeological site of “Le Colombare di Negrar” in northern Italy. Although the archaeological sediment samples examined are numerically exiguous, a comparative reading of our faecal biomarkers findings with new studies on faunal materials collected in the same stratigraphic detail during recent excavation campaigns will allow to better clarify the economic interest of the animal species farmed in the Colombare site (such as bovines, goats, sheep and pigs) and to shed light on the management of breeding. Together with archaeozoological and archaeobotanical analyses, the investigation of faecal biomarkers can increase our knowledge of how ancient local communities exploited natural resources and may allow us to deduce what their impact on the landscape was.

GermanIum array for non-destructive testing (GIANT) setup for muon-induced x-ray emission (MIXE) at the Paul Scherrer Institute

The usage of muonic x-rays to study elemental properties like nuclear radii ranges back to the seventies. This triggered the pioneering work at the Paul Scherrer Institute (PSI), during the eighties on the Muon-induced x-ray emission (MIXE) technique for a non-destructive assessment of elemental compositions. In recent years, this method has seen a rebirth, improvement, and adoption at most muon facilities around the world. Hereby, the PSI offers unique capabilities with its high-rate continuous muon beam at the Swiss Muon Source (SμS). We report here the decision-making, construction, and commissioning of a dedicated MIXE spectrometer at PSI, the GermanIum Array for Non-destructive Testing (GIANT) setup. Multiple campaigns highlighted the outstanding capabilities of MIXE at PSI, e.g., resolving down to 1 at. % elemental concentrations with as little as 1 h data taking, measuring isotopic ratios for elements from iron to lead, and characterizing gamma rays induced by muon nuclear capture. On-target beam spots were characterized with a dedicated charged particle tracker to be symmetric to 5% with an average σ = 22.80(25) and 14.41(8) mm for 25 and 45 MeV/c, respectively. Advanced analysis of the high-purity germanium signals further allows us to improve energy and timing resolutions to ∼1 keV and 20 ns at 1 MeV, respectively. Within the GIANT setup, an average detector has a photopeak efficiency of ϵĒ=0.11% and an energy resolution of σĒ=0.8keV at E = 1000 keV. The overall performance of the GIANT setup at SμS allowed us to start a rich user program with archaeological samples, Li-ion battery research, and collaboration with the industry. Future improvements will include a simulation-based analysis and a higher degree of automation, e.g., automatic scans of a series of muon momenta and automatic sample changing.

Carbon mapping in steel using 12C(d,pγ)13C in external beam

Carbon concentration and distribution has a dramatic impact on mechanical properties of steel. The manufacture technology of ancient steel is an important question in archaeometallurgy, especially during medieval times when the production process evolves between indirect and direct modes. Steel is an iron alloy incorporating up to a few % of carbon in weight, heterogeneously clustered in various carbide phases that are usually imaged by metallographic microscopy after acid etching. We have investigated the capability to obtain in a direct, non-destructive way and quantitative maps of carbon in steel samples using the 12C(d,pγ)13C reaction with the simultaneous detection of the emission of the 3089 keV γ-ray (d-PIGE) and of the p0 proton group (d-NRA). Carbon spot measurements and mappings were carried out using an external deuteron microbeam of 1.5 MeV at the New AGLAE facility of the Centre de Recherche et de Restauration des Musées de France. The beam diameter on the target was around 50 µm and its mean intensity 4nA, monitored by using the PIXE signal (Fe Kα line) emitted by the sample. Spectra were fitted using the SIMNRA program and the calculated composition checked against standard reference steel targets. Carbon distribution maps were extracted from the collected γ-ray and proton spectra datacubes. Spot measurements acquired in 2 min yielded a limit of detection of 200 ppm carbon weight for d-PIGE and 10 ppm for d-NRA. Proton detection appeared more effective than γ-ray detection owing to better statistics, mainly due to higher detection efficiency and better S/N ratio while γ-rays detection is affected by the spurious emission from nitrogen contained in the exit foil. Carbon concentration was mapped on a medieval archaeological iron alloy sample (140 × 32 points, 7 mm × 1.6 mm area) using a 1.6 sec dwell time, yielding a carbon content of 0.395 % with an uncertainty of 10 %. Heterogeneities could be evidenced in the maps, and incidentally the presence of oxygen. A simple methodology was developed to derive the depth distribution maps of carbon in the first microns of the sample.

Estimating fertility using adults: A method for under‐enumerated pre‐adult skeletal samples

Infant underrepresentation poses a great risk to accurate palaeodemographic findings when analyzing skeletal samples. Empirically derived palaeodemographic methods all require unbiased or minimally biased pre-adult representation for estimating demographic characteristics, including fertility. Currently, there are no reliable methods for estimating palaeodemographic parameters when pre-adults are underrepresented in skeletal samples, consequently such samples are often excluded from palaeodemographic analyses. The aim of this article is to develop a method for estimating total fertility rate (TFR) using reproductive aged adults, specifically for samples with suspected pre-adult under-enumeration. United Nations mortality data and TFR from the World Population Prospects was utilized. The correlation between known fertility and the proportion of individuals in key reproductive years (15-49 years) to total adult sample (15+ years) was assessed as an indirect means to estimate fertility. It was determined that the proportion of reproductive aged adults is a reasonable proxy for fertility. A significant positive correlation was observed between the TFR and those who died aged 15-49 years of age as a proportion of those who died ≥15 years (D15-49/D15+). SE of the estimate revealed reasonable predictive accuracy. When applied to two modern non-agricultural populations, the method showed some variability in accuracy but good potential for an improved outcome over existing methods when pre-adults are underrepresented. This research has provided a new method for estimating fertility in archeological skeletal samples with pre-adult under-enumeration. In combination with a contextually focused approach, this provides a significant step toward further use of biased samples in palaeodemography.

Electrochemical dating of archaeological gold based on repetitive voltammetry monitoring of silver/copper in depth concentration gradients

The use of repetitive voltammetry for dating archaeological gold objects is described. The method involves the record of the gold- silver-, and copper-related voltammetric responses obtained for metal nanosamples attached to graphite electrodes immersed into HCl electrolytes. This methodology permits to characterize different electrochemical types representative of different manufacturing techniques. Age estimates are based on the assumption that decuprification/desilvering processes advance with time under reasonably uniform conditions. Age calibration curves covering a range of ca. 2500 years were obtained from a set of archaeological samples from the Mapungubwe Gold Collection at the University of Pretoria Museums, South Africa, the Rijksmuseum of Amsterdam, The Netherlands, the Rheinische Landesmuseum Trier of Mannheim (Germany), the Museu de Belles Arts de Castelló, Spain, the Museu de Segovia, Spain, and the repository of the Servei d’Investigació Arqueològica Municipal de València, Spain.

Atmospheric Corrosion of Iron Artifacts in Museum Environments: Determination of Anions in Extraction Solutions Using Ion Chromatography

ABSTRACT It is well known that pollutants affect the deterioration of iron artifacts. To store iron artifacts in a suitable environment, it is imperative to understand the mechanisms of long-term corrosion in museum environments. Although many studies have been carried out to determine the corrosion behavior of iron artifacts, little research has been undertaken to quantify soluble ions in iron corrosion. In this study, the determination of anions in the extraction solution of archaeological iron and iron coupons produced in one-year monitoring experiments was conducted using ion chromatography. Monitoring was carried out in storage and galleries at four museums in different regions of China. The results show that the ion content of the experimental samples, including iron coupons and archaeological iron samples, reflects the atmospheric corrosion environment in the museum, where acetate, formate, and sulfate ions were found present in significant concentrations in the samples. The results produced will provide guides to the accelerated aging experiment of iron with pollutants in the next step of the project.

XRF Semi-Quantitative Analysis and Multivariate Statistics for the Classification of Obsidian Flows in the Mediterranean Area

Obsidian is a natural volcanic glass formed after eruptions if very rapid cooling of lava occurs. In particular conditions, the lava silicate ions cannot reach the crystalline lattice ordered formation and assume a chaotic arrangement, giving origin to obsidian flows. Obsidian has been used since the Paleolithic period to make tools because of its durability; in the Neolithic period, its trade played an important role in the Mediterranean area, and currently, obsidian is of particular interest for tracing prehistoric trading patterns. In this work, we present a semi-quantitative approach, exploiting energy-dispersive X-ray fluorescence (ED-XRF) coupled with principal component analysis. We consider geological samples from the five main collection sites of archaeological interest in the Mediterranean Basin (i.e., Pantelleria, Lipari, Palmarola, and Sardinia islands in Italy and Milos Island in Greece) and obtain a reliable classification of the fragments’ provenance, also comparing chemical fingerprints with data from the literature. Reported results show that this non-invasive semi-quantitative protocol could ease the application to archaeological samples, such as blades and splinters, permitting the classification of artifacts found in the archeological sites of the Mediterranean area even when relatively few samples are considered.

Electrochemical Chip Combined with Immunomagnetic Beads Enrichment for the Detection of Peach Gum Binding Medium in Ancient Wall Paintings

The sensitive determination of peach gum in aged wall painting was developed by combining protein A magnetic bead (MB) enrichment and an electrochemical immunosensor based upon a screen-printed electrode. Peach gum antibodies were immobilized onto protein A-functionalized magnetic beads with specific recognition. The prepared immunomagnetic beads (IMBs) efficiently enriched peach gum in archaeological samples, improving the accuracy. After elution, the peach gum was detected using an enzyme-linked immunosorbent assay and an electrochemical immunosensor constructed by screen-printing a three-electrode system on polyethylene terephthalate. The carbon working electrode was modified with gold nanoparticles to improve the conductivity. A detection limit of 6.4 pg·mL−1 was obtained using the immunosensor with a linear range from 0.01 to 100 ng·mL−1. Simulated wall paintings were prepared to assess the enrichment by the IMBs and the performance of electrochemical immunosensor. Archaeological samples from the Sulamani Guphaya Temple and Shi Wushe Tomb were analyzed and the results showed that more reliable results were obtained and false negatives were avoided after enrichment and electrochemical detection. Hence, IMBs were suitable for the determination of the peach gum binding medium in archaeological samples.

Multi-isotope fingerprints of recent environmental samples from the Baltic coast and their implications for bioarchaeological studies

Stable isotopes in coastal regions are influenced by the so-called sea spray effect which masks the actual terrestrial isotope fingerprint with a marine isotope signal. The sea spray impact on plants was investigated by analyzing different stable isotope systems (δ13Ccellulose, δ18Ocellulose, δ18Osulfate, δ34Ssulfate, δ34Stotal S, δ34Sorganic S, 87Sr/86Sr) in recent environmental samples (plants, soil, water) collected close to the Baltic Sea.All these isotopic systems are influenced by the sea spray, either by the uptake of ions (HCO3−, SO42−, Sr2+) of marine origin, thus exhibiting a marine isotopic signature, or by biochemical reactions associated with, e.g., salinity stress. A shift towards seawater values is observed for δ18Osulfate, δ34S, and 87Sr/86Sr. Cellulose becomes enriched in 13C and 18O due to sea spray, further enhanced (δ13Ccellulose) or mitigated (δ18Ocellulose) by salinity stress. The effect differs both regionally and seasonally, probably as a result of, e.g., differences in wind strength or prevailing wind direction, as well as between plants collected only few meters apart, in either the open field or at more wind-protected sites, reflecting samples more or less influenced by sea spray.The stable isotope data of recent environmental samples are compared to previously analyzed archaeological bone samples of animals from the Viking Haithabu and Early Medieval Schleswig sites located close to the Baltic Sea. Potential regions of origin can be predicted based on the magnitude of the (recent) local sea spray effect. This enables the identification of probably non-local individuals.The insights into sea spray mechanisms, biochemical reactions in plants, as well as seasonal, regional, and small-scale differences in stable isotope data will help to interpret multi-isotope fingerprints at coastal sites. Our study demonstrates the usefulness of environmental samples for bioarchaeological studies. Moreover, the detected seasonal and small-scale differences require adjusted sampling strategies for, e.g., isotopic baselines in coastal areas.

Study of thermal behavior and molecular composition of mixtures of resinous materials and beeswax found as adhesives in archaeological finds

Beeswax and resinous materials have been used and combined since ancient times to obtain adhesives. In this work, we studied mixtures of these two materials under heating to investigate the effect of their interactions on the properties of the resulting adhesive. The results were then compared with those of archaeological samples, to obtain new insights into ancient technological knowledge. This study was performed by combining two different chemical-analytical techniques: evolved gas analysis coupled with mass spectrometry and flow injection analysis-high resolution mass spectrometry. Evolved gas analysis was used to investigate the thermal behavior of the mixtures and obtain information on production techniques and ageing processes. The data were processed by isoconversional method to estimate the activation energies associated with the thermal degradation of the adhesives. The results suggested that archaeological mixtures were subjected to a thermal pre-treatment before their use as adhesives and that heating led to a material with new chemical features, due to the formation of hybrid species between resin diterpenes and the beeswax compounds. The formation of these species was confirmed by high resolution mass spectrometry.

Embracing diversity: a genetic marker dataset with increased marker density facilitates association studies in maize

Embracing diversity: a genetic marker dataset with increased marker density facilitates association studies in maize

Nonadult vertebral maturation in Late Holocene hunter‐gatherers from Patagonia (Salitroso Lake, Argentina)

AbstractBioarchaeological research of bone growth patterns provides information on the health status and disease of past populations. Recent studies have pointed out the potential of metric analysis of nonadult vertebrae as indicators of stress during different stages of ontogeny, highlighting that most vertebral measurements present low sexual dimorphism, a stable and known pattern of growth and give useful information even in incomplete spines. The aims of this paper are first, to construct a vertebral growth profile for nonadults of a skeletal series of Patagonian Late Holocene hunter‐gatherers from Salitroso Lake (SAC); second, to compare it to the ones obtained in other archaeological and modern populations with different stress experiences; and third, building on this, to assess whether individuals with evidence of stress experienced in early development demonstrate different patterns in vertebral growth than those without. Two spinal dimensions are used: vertebral body height (VBH) and transverse diameter of the neural canal (TDNC) in a sample of 23 nonadult skeletons with ages previously estimated from dental and bone indicators. The vertebral dimensions of 20 adults between 18 and 35 years of age were also measured as reference information. Results show that the growth of the VBH is steady over the years and reaches adulthood size by approximately 16 years of age whereas TDNC dimensions do not experience marked fluctuations in size throughout life and adult dimensions are reached at approximately 4 years of age as expected. The vertebral growth pattern observed in SAC is similar to that obtained in other archaeological samples from very different settings but experiencing relatively high nutritional or pathological stress in early stages of life. However, it is markedly different, and systematically smaller, to the 20th century sample pattern, probably responding to a secular trend in the modern population with a more stable access to resources and medical treatment. Finally, SAC individuals with systemic stress markers do not tend to exhibit smaller vertebral dimensions than those without them.

Testing the guidelines of the New Coimbra Method for recording entheseal changes via interobserver agreement in a Bronze Age skeletal sample from Kültepe‐Kanesh, Türkiye

AbstractThe New Coimbra Method is the most recently proposed standardized method to assess entheseal changes (EC). However, the method's developers acknowledge the inadequacy of their guidelines and state that those who will use the method need in‐person training from them. This study aims to determine the applicability of the method's guideline by testing the interobserver agreement (IOA) with observers who were not trained by the developers. The second objective of this study is to apply the New Coimbra Method to a relatively small archeological sample, in this case a Bronze Age population from Kültepe‐Kanesh, Türkiye. Four observers (the authors) scored EC in three entheses of the right upper limb of 52 adults. IOA was analyzed via Fleiss' kappa (FK) and percentage of agreement (PA) tests. FK test results indicate moderate overall agreement (0.458), while PA implies significantly high agreement (95%). The results of the FK and PA tests contradict each other due to the known limitations of the latter. However, FK values among features vary broadly; some of the features indicate substantial agreement and surpass the required benchmark, while the rest remains moderate or lower. The features that revealed substantial agreement indicate the sufficiency of the method's guidelines. However, the guidelines for the other features appear to be inadequate. Further revision of the guidelines could make the method more applicable for all researchers with no requirement of in‐person training.

Improved discrimination of biogenic and diagenetic elements in Palaeolithic mammoth ivory and bone from Hohle Fels Cave in the Swabian Jura of Southwestern Germany

Mammoth ivory was used by humans to manufacture personal ornaments, sculptures or music instruments during the Upper Palaeolithic. These objects are among the first and most precious witnesses of ancient artistic behaviour. Archaeological ivory, however, has been subjected to complex alteration processes due to exchange with its burial environment over time. Therefore, it is necessary to understand the diagenetic phenomena in order to develop adequate conservation measures for ivory artefacts. The element-analytical study of ivory artefacts can shed light on these processes and can help to track the origin of these objects.In this work we studied twelve mammoth ivory samples and ten bone samples coming from the Palaeolithic site Hohle Fels located in the Swabian Jura. Mammoth bone samples were included in the study in order to find eventual differences in the diagenetic changes between ivory and bone material. We performed ion beam analysis (PIXE/PIGE) at the microfocus beamline of the accelerator NewAGLAE at C2RMF and micro-X-ray fluorescence (XRF) mappings at the PUMA beamline at synchrotron SOLEIL. The obtained PIXE/PIGE results are consistent with previous studies of ivories from Hohle Fels and other contemporaneous European sites in terms of possible site-specific (Zn, Br, Sr contents) and diagenetic markers (F content). XRF mappings and their semi-quantitative analyses confirm former observations and provide additional criteria for the classification of endogenous and exogenous elements. Based on our results we could not find significant difference in the diagenetic alterations between archaeological ivory and bone samples for the studied archaeological site.

Intra-source provenance study on Monte Arci (Sardinia) obsidian by pXRF: Role of the data acquisition and analysis tools

In this work, a detailed study of Monte Arci obsidian sub-sources using the increasingly accessible technique of pXRF is presented based upon a large dataset of 68 geological samples, for the development of X-ray fluorescence-based analytical standardless procedure. In addition, a non-conventional (for obsidian provenance study) direct application of multivariate analysis on XRF spectra (continuous variables), rather than absolute concentrations or intensity ratios (discrete variables) is proposed.Results from different softwares and data analysis approaches (bi-/trivariate versus multivariate) were compared. In a blind test, the bi-/trivariate approach led to the correct assignment for the main SA, SB, and SC sub-sources, taking into account averaged values of intensity ratios with their standard deviation obtained from three independent measurements. A high intra-source variability for the SB subgroups was detected (almost 13% of error in the assignment, 9 samples out of 68). A non-conventional application of multivariate analysis was carried out directly on the XRF spectra and correct assignments were obtained for SA, SB1, SC groups, while 71% of the SB2 samples were correctly identified. The non-destructive analysis on 14 archaeological samples from Su Carroppu (Carbonia, southwestern Sardinia) rockshelter and from the Middle Neolithic (MN) 422 structure of the open-air dwelling site at Cuccuru is Arrius (Cabras, central-western Sardinia) permitted to test the method and hypothesise their provenance. The comparison with visual characterization or previous analyses by Particle Induced X-Ray Emission (PIXE) permitted to verify the correct provenance assignment of all artifacts for the bi-/trivariate method, and for 12/14 samples in the case of the multivariate one. The standardless analytical approach proposed in this work can represent a more general method exploitable for other obsidian sources, other glassy materials, besides other materials of archaeological interest.

Technical note: Application and potentiality of quantitative ultrasonometry for the evaluation of bone mineral density status.

The evaluation of bone mineral density (BMD) is an important task in paleopathology. Techniques commonly applied in bone quantity assessment, such as DXA or radiogrammetry (XR), suffer from several limitations when applied to skeletal remains. In recently published research, we developed a new methodology and new reference curves for the evaluation of BMD on human skeletal remains, applying for the first time Quantitative Ultrasonometry (QUS), a user-friendly, portable, and reliable clinical technique. This study aims to apply this new methodology to an archeological sample and to compare the results with those obtained through XR. We apply QUS and XR to a sample of 104 adults from Medieval Italian cemeteries. Fragility fractures were recorded. Descriptive statistics and comparisons between sexes, age-at-death cohorts, and individuals with and without fragility fractures were performed. Moreover, univariate and multivariate logistic regression models were used to define the parameters most predictive of fracture risk in past populations. The comparison between sexes showed no significant results concerning BMD parameters, whereas a decrease in BMD with increasing age is confirmed. The comparison between fracture and non-fracture individuals and the logit model demonstrated that QUS parameters, especially UBPI, are more reliable predictors of fracture risk in comparison to XR. Our results confirmed that QUS is a valuable technique that can be efficiently applied to archeological remains, also considering its portability. We also propose a modification of the previously published QUS standard curves, to easily assess osteopenia and osteoporosis in archeological material.

Machine Learning–Based Identification of Lithic Microdebitage

ABSTRACTArchaeologists tend to produce slow data that is contextually rich but often difficult to generalize. An example is the analysis of lithic microdebitage, or knapping debris, that is smaller than 6.3 mm (0.25 in.). So far, scholars have relied on manual approaches that are prone to intra- and interobserver errors. In the following, we present a machine learning–based alternative together with experimental archaeology and dynamic image analysis. We use a dynamic image particle analyzer to measure each particle in experimentally produced lithic microdebitage (N = 5,299) as well as an archaeological soil sample (N = 73,313). We have developed four machine learning models based on Naïve Bayes, glmnet (generalized linear regression), random forest, and XGBoost (“Extreme Gradient Boost[ing]”) algorithms. Hyperparameter tuning optimized each model. A random forest model performed best with a sensitivity of 83.5%. It misclassified only 28 or 0.9% of lithic microdebitage. XGBoost models reached a sensitivity of 67.3%, whereas Naïve Bayes and glmnet models stayed below 50%. Except for glmnet models, transparency proved to be the most critical variable to distinguish microdebitage. Our approach objectifies and standardizes microdebitage analysis. Machine learning allows studying much larger sample sizes. Algorithms differ, though, and a random forest model offers the best performance so far.