Obsidian Artifacts Research Articles

Circulation of Goods and Information in Southern Patagonia During the Late Holocene: An Integrated Analysis of Engravings and Black Obsidian Artefacts

Circulation of Goods and Information in Southern Patagonia During the Late Holocene: An Integrated Analysis of Engravings and Black Obsidian Artefacts

Folsom obsidian conveyance at the Great Divide Paleoindian sites, Wyoming

We present a study of obsidian artifacts found in Folsom contexts from the Great Divide Paleoindian sites (Great Divide Basin, Wyoming) to evaluate Paleoindian mobility patterns in the central and southern Rocky Mountains. Obsidian sourcing using pXRF demonstrates conveyance from Obsidian Cliff (400 km), Teton Pass (300 km), and the Green River/Engineer Quarry source. Other chipped stone raw materials from Folsom localities derive from sources in the upper Green River Basin, thus partially establishing a Folsom mobility pattern between the Yellowstone Plateau, upper Green River Basin, and Great Divide Basin of Wyoming. This study supports the notion that Paleoindians regularly transported lithic raw materials great distances even in relatively raw material rich regions like the interior of the Rocky Mountains and is further evidence for a sparsely documented Younger Dryas-aged use of the Yellowstone Plateau.

Reconstructing Neolithic obsidian procurement in Western Georgia through an obsidian characterization study

The Caucasus, situated strategically in terms of natural geography and abundant raw materials, has been attractive to the interest of prehistoric hunter-gatherers throughout ancient times. Recent discoveries at the Neolithic site of Makhvilauri in the Ajara region, affirm this historical focus. The Makhvilauri flaked stone tool assemblage encompasses various lithic resources, of which ∼11 % (n = 59) comprise obsidian, a raw material whose closest sources are 170 km away. Using the XRF method at the Archaeometry Laboratory at the University of Missouri Reactor Research (MURR) to elementally characterise 23 of the obsidian artifacts (∼39 % of the total) we can demonstrate that the Makhvilauri assemblage was made from at least five geochemically distinct sources. This analysis not only sheds light on the mobility patterns of ancient communities but also underscores the extensive contacts established during the Neolithic period (6th millennium BC).

Obsidian Sources and Source Provenance of Archaeological Obsidian in Northern Sonora: The Known and Unknown

A recent obsidian provenance study in three sites in the Valle de Altar region of northern Sonora has greatly expanded our understanding of the prehistoric relationship between the southern and northern Sonoran Desert. Based on obsidian source provenance, archaeological sites in the Valle de Altar indicate that contact with the region as far north as west-central and northern Arizona, the northern portion of the Papaquería, the Sierra Pinacate, the Sierra Madre Occidental, and the Basin and Range of Chihuahua was potentially frequent. However, the vast majority of artifacts produced from obsidian were procured apparently locally from an, as yet, unlocated source called here “SON Valle de Altar Unknown.” The purpose here is to discuss the relevant regional geology, the source provenance of the obsidian artifact assemblage, and relationships throughout the greater Sonoran Desert. This project also adds significant data to the Southwest Archaeological Obsidian Project (http://swxrflab.net/).

Obsidian hydration dating by infrared transmission spectroscopy

AbstractThe obsidian dating method converts the quantity of diffused molecular water within a near‐surface hydration layer to elapsed time using an experimentally derived diffusion coefficient predicted from the structural water content of the glass. Infrared spectroscopic transmission measurements on transparent archaeological samples record vibrational responses of water bands in the near‐infrared region, permitting determination of structural water content (OH), and the amount of diffused ambient water (H2O). In this application, the H2O water band at 5200 cm−1 is measured directly. The accuracy of the approach is assessed by an evaluation of the precision of each contributing variable. The new protocol is evaluated using obsidian artifacts from radiocarbon‐dated deposits at Salamanca Cave in Argentina.

Social Network Analysis of Ancient Japanese Obsidian Artifacts Reflecting Sampling Bias Reduction

Social Network Analysis of Ancient Japanese Obsidian Artifacts Reflecting Sampling Bias Reduction

Obsidian Procurement and Exchange at the Apogee of Empire: Wari Political Economy in Arequipa, Peru

Abstract During the Middle Horizon (AD 600–1000), obsidian was transported in greater quantities and distances than ever before identified in the Andes, in part by the expansionary Wari state. Two of the three major obsidian sources used in the south-central Andes are located in the modern department of Arequipa, Peru. Arequipa was a region of intense Wari influence and intrusive presence; however, little is known about regional obsidian use. Portable X-ray fluorescence (pXRF) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) were used to analyze 383 obsidian artifacts recovered from 10 archaeological sites in Arequipa. Results highlight diachronic and spatial patterning related to obsidian procurement strategies, state versus bottom-up exchange networks, and local participation within the Wari realm. A wide variety of geological obsidian sources, including nonlocal obsidians originating from Wari's Ayacucho heartland, were used. By the late Middle Horizon, the Wari had consolidated regional resources with the sole use of Alca-1 and Alca-4 bedrock obsidians, the largest-sized and highest-quality sources in the area. We assess related models of obsidian procurement and exchange related to state political economy, long-distance caravan activity, and the role of local ceremonial/waystation centers that facilitated the flow of ideas, goods, and people across Arequipa.

Archaeometric analysis of the obsidian assemblage from Hodoni/Hodony (Banat, Romania)

Hodoni “Pocioroane” is one of the archaeological sites discovered near the village of Hodoni/Hodony, ca. 25 km north of Timişoara, in the Romanian Banat. The excavations carried out at “Pocioroane” have yielded traces of superimposed Neolithic settlements and a medieval cemetery. This paper considers 113 obsidian artefacts recovered during the excavations carried out between 1985 and 1991 in the Vinča C2 and Tisza culture layers and features. The obsidian artefacts are represented by waste flakes, bladelets, exhausted cores and a few retouched tools two of which show utilisation marks. The artefacts have been characterised by LA-ICP-MS and XRF methods at the CNRS laboratory of Orléans University (France) indicating a Carpathian 1 provenance.

Techno-typology and provenance of the obsidian chipped stones from Sofular Höyük, an Early Neolithic settlement near the Kızılırmak in Central Anatolia

Recent excavations at Sofular Höyük (Nevsehir, central Turkey) uncovered Aceramic Neolithic deposits dating to the late 9th and early 8th millennium cal BC and a lithic industry almost entirely made of obsidian. This study focuses on the techno-typology of this lithic assemblage and provides a first look at the material procurement strategies through geochemical characterization. Our results show that Sofular Höyük shares many general techno-typological features with contemporary sites in Central Anatolia, placing the settlement within the locally rooted traditions of the region, while the pXRF analysis of a selection of obsidian artefacts indicates the presence of two Cappadocian sources, namely Göllüdağ and Acıgöl.

A novel approach to documenting water diffusion in ancient obsidian artifacts via the complexity analysis of microscope images

The diffusion of water through the surface of archaeological obsidian is mainly a temperature-dependent and concentration driven phenomenon that forms the basis of the hydration dating (OHD) method. For the first time, we apply a novel fractal approach, which explores the various attributes of images linked to the variation in water concentration and structural deficiencies within the hydrated layer. The microscopic images of hydrated layers on two obsidian specimens from Africa spanning thousands of years have been investigated. Seven complexity measures of fractal dimension (succolarity, lacunarity, correlation dimension, local connected fractal dimension (LCFD), fractal fragmented index (FFI), entropy and normalized Kolmogorov complexity (TIFF-LZW)), were applied to the hydration layer images. It was found that the effective determination of diffusion depth mainly comes from the application of succolarity, FFI and LCFD fractal indices, plus the structural deficiencies at the surface and the misconnected lacunas at the interface of the water diffusion layer and unaltered obsidian. The difference between fractal dimensions of the hydrated area and the non-hydrated images turned out to be a crucial quantitative parameter. Accordingly, we found that especially the succolarity, which is based on the capacity of a water fluid to percolate through the obsidian area in a given direction, was critical to determine the characteristics of the obsidian hydration layer. The FFI and LCFD estimate the compaction/fragmentation and connectivity, respectively. Therefore, the fractals play an important role in understanding the general diffusion in solids theory and the study aims at providing a new direction in the OHD and diffusion fields concerning the complex dynamic systems and structures which display a fractal pattern.

New data from old collections: Obsidian and ostrich eggshell beads from the 1977 Mehlman excavations at Mumba rockshelter, Tanzania

Mumba rockshelter in northern Tanzania has served as a key benchmark sequence for understanding Late Pleistocene-Holocene archaeological changes in the region. A complete understanding of the site is complicated by multiple excavations across >90 years, with an unfortunate history of incomplete publication of those results, particularly for some of the older, larger-scale excavations from the 1930s and 1970s. We report here on newly recovered material from the 1977 Mehlman excavations at Mumba. We (1) untangle the complex notation Mehlman used when labeling his artifacts which has led to a misunderstanding of some patterns of change in the past, (2) present the first fully quantitative results of the geochemical analysis and source attribution of obsidian artifacts from Beds III and II at the site, and (3) test and confirm observations about a lack of change in ostrich eggshell bead size at Mumba, a pattern unlike that found at other regional sequences.

Ice Patches and Obsidian Quarries: Integrating Research Through Collaborative Archaeology in Tahltan Territory

ABSTRACT This article presents the results of archaeological survey of ice patches in the vicinity of the vast obsidian quarries and artifact scatters found near Goat Mountain and the Kitsu Plateau in Mount Edziza Provincial Park, Tahltan Territory. During the survey, over 50 perishable artifacts were found, including stitched birch bark containers, wooden walking staffs, carved and beveled sticks, an atlatl dart foreshaft, and a stitched hide boot. Radiocarbon ages on 13 of the perishable artifacts reveal that they span the last 7000 years. These finds were made against a massive and stunning backdrop of scattered obsidian artifacts: bifaces, cores, flakes, and raw material nodules. This project collaborated with the Obsidian Discoveries Tahltan Tene Mehodihi Youth Group Hike and the “Our Ancestors’ Trail” museum exhibition. This collaboration resulted in connections between the archaeological results presented here, community learning, and artistic inspiration.

New results of obsidian artifact analysis from the middle and lower basin of the Salado stream, Río Negro province, Argentina

AbstractThe Salado and Verde streams constitute the two main seasonally available freshwater courses that flow into the Atlantic coast of the Río Negro province (continental Patagonia, Argentina, 42° South). This would have favored their use in the past as corridors for human circulation between the coast and the interior. This paper presents the results of the technomorphological and geochemical analyses of the obsidian artifacts recovered in the area to constrain mobility. The results allow us to propose the existence of toolkit reconditioning or replacement activities, and the identification of different sources of provenance of the obsidians (Sacanana, Telsen, and Portada Covunco, distant up to 800 km from the study area), reinforcing the hypothesis of a coast–inland circulation, with the possible existence of circuits of exchange of this raw material.

Connecting Obsidian Artifacts with Their Sources Using Multivariate Statistical Analysis of LIBS Spectral Signatures

With the recent introduction of handheld instruments for field use, laser-induced breakdown spectroscopy (LIBS) is emerging as a practical technology for real-time in situ geochemical analysis in the field. LIBS is a form of optical emission spectroscopy that is simultaneously sensitive to all elements with a single laser shot so that a broadband LIBS spectrum can be considered a diagnostic geochemical fingerprint. Sets of LIBS spectra were collected for seven obsidian centers across north-central California, with data processed using multivariate statistical analysis and pattern recognition techniques. Although all obsidians exhibit similar bulk compositions, different regional obsidian sources were effectively discriminated via partial least squares discriminant analysis. Obsidian artifacts from seven archaeological sites were matched to their putative sources with a high degree of confidence.

Obsidians from the Archaeological Site of San Francisco Toxpan, Mexico: Supply Sources and Trade Routes

The obsidian artifacts from the San Francisco Toxpan excavation in Veracruz, Mexico, dating from the Proto-Classic to the Mid-Post-Classic periods, were analyzed using instrumental neutron activation and statistical methods. The sources of these artifacts were Guadalupe Victoria and Zaragoza-Oyameles in Puebla, Pico de Orizaba in Veracruz, Sierra de Pachuca in Hidalgo, and Paredón in Puebla. The majority of the artifacts came from the first three sources, which are closest to the site. San Francisco Toxpan was into the trade route from the Central Highlands to the Gulf Coast but with limited influence from major cities like Teotihuacan or Cantona. The independence of these cultures likely allowed for the development of a local lithic industry, facilitating trade through the Jamapa-Cotaxtla basin. The intricate process of obtaining obsidian for the residents of Toxpan becomes evident when considering the diverse sources of these materials.

Obsidian in the Valley of Volcanoes, Peru

The Andagua Valley in the Department of Arequipa of southern Peru has only recently seen systematic archaeological investigations, revealing ancient agricultural communities that, despite apparent geographic isolation, were integrated economically with the wider Andean world. Portable x-ray fluorescence analysis of 137 obsidian artifacts recovered from sites in the lower Andagua Valley identifies the transfer of obsidian from Peru’s three largest sources, with > 90% of the analyzed artifacts coming from the Alca-1 source northwest of the valley. In addition to Alca-1 obsidian, small amounts of obsidian from the distant sources of Chivay and Quispisisa appeared in distinct contexts associated with local pre-Inka occupations, corresponding with the Middle Horizon and Late Intermediate Periods (600 – 1000 and 1000 – 1400 Common Era). Obsidian from the Alca-4 and Alca-5 sources, originating on the adjacent plateau, was also transported to Andagua during these periods, possibly continuing under Inka imperial expansion after 1400 CE.Because there is no archaeological evidence of either Wari or Tiwanaku states in the lower Andagua Valley, the probable mechanisms of obsidian transfer include direct or down-the-line exchange between plateau-based camelid pastoralists and valley farmers. Therefore, at least some long-distance obsidian transfers in southern Peru were carried out without direct oversight from Wari or Tiwanaku, though these transfers may have been facilitated by region-scale economic integration during the Middle Horizon and Late Intermediate Period. Tracing the distribution of obsidian in the Andagua Valley highlights both intra-valley and inter-zonal relationships between the Valley of the Volcanoes and specific areas of the high-elevation Andean plateau while illuminating dynamic economic and social connections along the central Andes in the pre-Hispanic past.

Obsidian hydration dating helps understand pre-hispanic land use on the volcanic island of Tenerife, Canary Islands, Spain

Critical to the survival of island-based human societies is their resilience and adaptation to volcanic hazards. We here evaluate pre-Hispanic (before 15th century AD) land use patterns on the volcanic island of Tenerife, Canary Islands, Spain using obsidian hydration dating (OHD). The samples studied include archaeological artifacts and natural rock chips from multiple sites of different elevation and micro-climate settings. We systematically collected samples from the southern dry area around Barranco de las Monjas in the Bandas del Sur. These include a total of 28 isolated artifact scatters (here, a scatter is defined as a minimum spatial unit of artifacts distributed spatially limited range on the surveyed surface), one dwelling, and several pyroclastic deposits containing obsidian clasts. We also collected several artifacts adjacent to a large obsidian flow of Tabonal Negro in the Las Cañadas Caldera. Unsystematic surveys in north of Mt. Teide identified large obsidian outcrops located at Tabonal de los Guanches and Charco del Viento. Size differences among surface-derived obsidian artifacts (i.e., Bandas del Sur, Las Cañadas Caldera, Icod Valley) suggest that pre-Hispanic groups utilized obsidian from multiple outcrops over wide areas. Hydration analysis on 136 obsidian flakes collected from both surface and buried contexts showed only minor obsidian hydration rims (5% of total samples) and varied mean rim thicknesses (0.6–3.5μ). The low percentage of hydration rim formation may be caused by environmental factors such as wind erosion, thermal effects from volcanic or natural ground fires, or due to obsidian geochemistry (low SiO2 and water content of phonolitic obsidian). Surface-collected obsidian flakes from the southern dry area do contain hydration rims along internal fissure. The estimated hydration rates from these samples can provide an approximate age when compared to buried obsidian artifacts with associated radiocarbon dates.

Obsidian Artifacts from Multiple Sources and Subsources at Valdesi in Western Sicily

Forty-two obsidian artifacts excavated at the site of Valdesi in western Sicily were analyzed to determine their geological sources and to reconstruct trade patterns. Non-destructive analysis was performed using a portable, non-destructive X-ray fluorescence spectrometer, with the calibrated element’s composition values compared directly with a dataset of geological samples from the Mediterranean and European sources that were analyzed with the same instrument. The results, based on straightforward X-Y graphs using the trace elements Rb, Sr, Y, Zr, and Nb, showed the presence of obsidian from two subsources on Lipari (Gabellotto Gorge, Canneto Dentro), two on Pantelleria (Balata dei Turchi, Lago di Venere), and one on Sardinia. The majority coming from Lipari coincided with the location of Valdesi, and nearly 20% came from Pantelleria, both consistent with the overall distribution patterns for Sicily, while the one from Sardinia is a unique discovery. These results are discussed in terms of the time period and context for Valdesi, as well as the open-water and land-based routes that must have been taken.

Combined in situ XRF–LIBS analyses as a novel method to determine the provenance of central Mediterranean obsidians

This work presents a new calibration method for determining the provenance of obsidian artefacts based on the combined use of XRF and laser-induced breakdown spectroscopy (LIBS). At first, obsidian samples collected from the main Mediterranean sources were characterized using portable XRF and LIBS systems. After data treatment, elemental information was used to carry out principal component analysis (PCA) for each technique. Rb, Sr, Zr, Y and Fe elements, detected by using XRF, were found to be the key parameters enabling obsidians discrimination. Likewise, LIBS data helped differentiating the analysed patterns by the intensity of their main elemental components (Ca, Al, Mg and K). After selecting the key parameters detected by each technique, a new data matrix combining XRF and LIBS data was finally built. According to PCA results, the discrimination of Mediterranean sources based on combined XRF–LIBS data ensured a higher reliability over mono-analytical models, by increasing the Euclidean distance between sources projections over three-dimensional principal components plots. Knowing that the representativeness of elemental data could be compromised by the presence of superficial degradation products or deposition patinas, a shot-to-shot comparison of in-depth LIBS analyses is finally proposed as a method to disclose whether the spot under analysis was superficially contaminated or altered. Thus, the proposed strategy based on the combined use of portable XRF and LIBS spectrometers could be particularly useful for the in situ analysis of obsidian artefacts that underwent superficial alteration or could be covered by patina products.Graphical abstract

In-Field Obsidian XRF Analysis of Sites in the Lion Mountain Area and Gallinas Mountains of West-Central New Mexico

ABSTRACT The Gallinas Mountains of west-central New Mexico were home to agriculturalists between ca. a.d. 850 and 1450. Ongoing research of the Lion Mountain Archaeology Project (LMAP) has allowed for in-field analysis of surface obsidian artifacts via portable handheld energy dispersive X-ray fluorescence spectrometry (ED-XRF). Influenced by principles of preservation archaeology and the archaeological repository curation crisis, the LMAP has sought to design and conduct field research to gather the most data with the least amount of impact to sites. Non-destructive in-field analysis via portable handheld ED-XRF subscribes to these goals while also providing answers to significant questions about human behavior. Results show that variable patterns of obsidian source utilization and procurement strategies existed both through time and between contemporaneous populations. These results are indicative of a shifting system of exchange and social interaction between residents of the region and surrounding areas during the Ancestral Pueblo occupation of the area.