Obsidian Outcrops Research Articles

Value, significance and use of 'exotic' materials – in the light of the presence of obsidian on Neolithic sites in Poland

At Neolithic archaeological sites in Poland, obsidian stands out as the most common ‘exotic’ raw material. Thereare over several hundred Neolithic sites where artefacts made from this raw material have been recovered. Given the absence of natural obsidian outcrops in Poland, it is evident that these artefacts were imported to the sites through various means, such as direct procurement or exchanges.One of the most extensive collections was found at Opatów, representing the Samborzec-Opatów group of the Late Neolithic. This collection forms the core of our discussion, in which we aim to explore the economic systems involved in the acquisition of obsidian. Results obtained from our analyses (technological, morphological, and traceological) constitute the foundation for considering various hypotheses regarding the significance and value of ‘exotic’ materials for Neolithic communities.

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.

Geochemical changes in obsidian outcrops with elevation at Hatis volcano (Armenia) and corresponding Lower Palaeolithic artifacts from Nor Geghi 1

Most descriptions of obsidian-bearing rhyolitic lava flows and domes are largely based on relatively simple cases of tectonic plate subduction in North America, but Armenian geologists proposed since the 1960s that these models are less suitable for describing rhyolitic volcanism in their research area. Obsidian-producing volcanoes that lie in the Armenian Highlands, they argued, are more complex in form and stratification. Hatis volcano in central Armenia is one such example. As we document, Hatis is highly unusual, perhaps unique, in that its obsidian changes in composition with elevation. Prior studies of Hatis obsidian recognized the existence of two different chemical types. Here, though, we report a series of four obsidian chemical types and their spatial distributions across the slopes. Our findings were enabled by the use of portable XRF during our field surveys of Hatis. Additionally, we recognized each of these four chemical types of Hatis obsidian at the Lower Palaeolithic site of Nor Geghi 1, where thousands of obsidian artifacts reflect Pleistocene hominin behaviors from Marine Isotope Stage (MIS) 11 (~424–374 ka) to 9 (~337–300 ka). Thus, all four types of Hatis obsidian are archaeologically significant despite the fact that their outcrops span more than 500 m (from <1600 to greater than 2100 m asl) in elevation on the volcanic slopes, thereby enabling future studies on links between altitude and hominin toolstone acquisition behaviors over hundreds of millennia.

Consuming local: The new obsidian source of Ideloo (Northwestern Iran) and first evidence of use by neighbouring prehistoric communities

AbstractThis paper reports the results of a recent geological and archaeological survey conducted in the Sarab district (Sabalan area) in Northwestern Iran. This survey aimed to identify potential obsidian outcrops in the region and to investigate archaeological sites in the vicinity to assess their obsidian exploitation patterns. We located a new obsidian source, Ideloo, and surveyed the previously known archaeological sites of Tepe Qalehjoogh, Kultepe Asbfrooshan, Tepe Emam Chay and Qaleh Tepe Abarghan. Here, we describe the methods and results of our surveys, along with the geochemical characterisation, using portable XRF and LA‐ICP‐MS, of both the new outcrop and the obsidian artefacts found on the sites. Our analyses have revealed the consumption of Ideloo obsidian on three of the four sites surveyed, confirming its exploitation by local communities. While validating previous assumptions regarding the existence of potential obsidian sources in Northwestern Iran, our study also highlights the consumption of raw materials originating from the Caucasus or Eastern Anatolia in complement to local resources. However, the diffusion of the Ideloo obsidian seems so far restricted to a small area, which suggests more complex consumption and trade patterns than previously expected.

Petroarcheometric Analysis on Obsidian Artefacts Found Within Some Neolithic – Eneolithic Period Caves of Southern Italy

AbstractIn the last twenty years, obsidian artefacts have been found in important and often extensive karst cavities in Southern Italy: three located in Calabria (Grotta della Monaca, and Grotta del Tesauro, in Sant’Agata di Esaro, Cosenza; Grotta Pietra Sant’Angelo in San Lorenzo Bellizzi, Cosenza), one in Puglia (Grotta di Santa Barbara in Polignano a Mare, Bari) and another in Campania (Grotta di Polla, Salerno). All these sites, that have returned a total of 151 obsidian tools, were connected to human frequentation of the underground environments that occurred during the Holocene, which can be precisely located in the vast period between the Neolithic and the Eneolithic (6th–4th millennium BC). They are mainly blades and bladelets, but also burins together with scrapers and cores, generally of small dimensions. SEM-EDS and WD-XRF absolutely non-destructive analyses carried out on these items have shown that all samples have a source area in the obsidian outcrops of the island of Lipari (Messina, Italy). These data confirm that the Aeolian island of Lipari furnished the privileged obsidian extraction outcrops for most of the Neolithic and Eneolithic archaeological sites of Southern Italy.

The provenance of obsidian artefacts from the Middle Kingdom harbour of Mersa/Wadi Gawasis, Egypt, and its implications for Red Sea trade routes in the 2nd millennium BC

This paper presents the results of the geochemical analysis carried out on the obsidian artefacts discovered at the archaeological site of Mersa/Wadi Gawasis, located along the Egyptian Red Sea coast, in between the modern cities of Safaja and Quseir. During the 12th and 13th Dynasties of Egypt the site hosted a port city from where the Egyptian expeditions set sail directed to the south, on both edges of the Red Sea. Six obsidian artefacts collected during the 1970s’ research carried out at the site by A. Sayed, were geochemically analysed, together with five geological samples from the obsidian Kusrale source in Eritrea. The major element concentrations were determined by SEM-EDS analysis and the trace element concentrations were obtained by LA-ICP-MS method, a micro-destructive technique, capable of chemically characterizing the volcanic glass. A comparison of geochemical results obtained on the archaeological artefacts and geologic samples, together with the literature data on different geological obsidian outcrops from the Horn of Africa and the southwestern Arabian peninsula, allowed us to determine the provenance of the Mersa/Wadi Gawasis obsidian artefacts in both the Kusrale source of Eritrea, and the volcanic area of Dhamar Reda in Yemen. These results can provide further insights on ancient trade routes along the Red Sea during the early second millennium BC.

Petroarchaeometric Data on Antiparos Obsidian (Greece) for Provenance Study by SEM-EDS and XRF

Abstract The island of Antiparos belongs to the Aegean volcanic arc. The obsidian outcrops here contain pieces of excellent tool-making quality, but of small size making the raw material less attractive. Geological samples collected at Soros beach, at Blaco and Mastichi, in the southern part of the island, were analysed using Optical Microscopy, XRF (whole rock) and SEM-EDS (glass and microliths-microphenocrysts). The results obtained demonstrate the potential for distinguishing the Antiparos obsidian from other major central-western Mediterranean sources in an absolutely non-destructive way, using an XRF spectrometer or alternatively with an SEM equipped with an ED spectrometer.

Characterization and Provenance of Archaeological Obsidian from Pirozza-Spalmatore, a Site of Neolithic Colonization on the Island of Ustica (Sicily)

Abstract This article presents the first archaeometric research carried out so far on a group of obsidian artifacts collected in the promontory of Pirozza-Spalmatore, the site of a Neolithic settlement on the small island of Ustica (Sicily, Italy). The obsidian assemblage, consisting of 28 artifacts, was subjected to optical, typological and geochemical analyses, the latter carried out by means of a portable pXRF, in order to determine their provenance. The results indicate that 89% of the fragments come from geologic obsidian outcrops on the island of Lipari, and 11% from the island of Pantelleria. It is thus ascertained that, during the Neolithic, Ustica used two different sources of obsidian, located 150–250 km away from the site. These obsidian sources were typical of some western Sicily prehistoric villages, while eastern Sicilian villages seem to have imported obsidian exclusively from Lipari. The analyses indicate that all the obsidian artifacts attributed to Lipari come from the geological deposit of Gabellotto, while those attributed to Pantelleria come from the two distinct deposits of Lago di Venere and Balata dei Turchi.

COUGAR CREEK: QUANTITATIVE ASSESSMENT OF OBSIDIAN USE IN THE GREATER YELLOWSTONE ECOSYSTEM

With more than 15 sources of obsidian and other lithic materials, the Greater Yellowstone Ecosystem of Montana, Wyoming, and Idaho is one of the richest toolstone regions in northwestern North America. This article introduces a quantitative assessment technique to compare attributes of seven Yellowstone obsidians used by Native Americans over at least 11,000 years. The proposed assessment technique is replicable and adaptable to other regions. This article also analyzes the procurement, use, and distribution of the poorly studied Cougar Creek obsidian. Archaeological research documented Cougar Creek obsidian outcrops, procurement areas, and secondary processing sites. Native Americans acquired the material at surface exposures, as well as occasional trench and pit excavations. There is a significant distance decay reduction in its use, especially when compared with Obsidian Cliff obsidian. Using a weighted z-score analysis, the material attributes of Cougar Creek were compared with those of six regional obsidians to determine the factors involved in their differential use. Based on these rankings, Cougar Creek obsidian experienced low demand and usage due to poor quality and availability. In contrast, due to their high quality, abundance, and aesthetics, Obsidian Cliff and Bear Gulch obsidians were preferred for stone tool production.

Long-distance provenance for obsidian artifacts of Mesoamerica Preclassic and Early Classic periods found in the Los Naranjos Archaeological Park (Honduras)

Los Naranjos is one of the most important pre-Columbian human settlements of Honduras related to the south-easternmost border of the Mayan civilization. Although the archaeological site mostly spans from 850 BC to 1250 AD, the present obsidian study was only focused on the Preclassic and Early Classic periods (Jaral, 800–400 BC and Eden, 400 BC–550 AD) where undamaged blades and/or retouched obsidian flakes are rare. In this way, the INAA analyses of 17 obsidian samples, compared with major-trace elements data of Honduran and Guatemalan obsidian sources, are mostly representative of waste flakes. Lithic artifacts of Los Naranjos such as sandstones, basalts, and quartzites come from local geological outcrops; whereas, obsidian provenance has to be searched from sources which are located within a radius up to 300 km far away. San Luis, La Esperanza, and Guinope obsidian sources are located in Honduras while the three most exploited Highland Guatemalan obsidian outcrops, which have been dominating long-distance trade in the Maya area mostly for the Classic-Postclassic periods, are San Martin de Jilotepeque, El Chayal, and Ixtepeque. An Ixtepeque provenance, for all the investigated obsidian samples of Preclassic and Early Classic periods found in the Los Naranjos Archaeological Park, was established, thus emphasizing a long-distance source (180 km). This also confirms that Ixtepeque represents the most important provenance of the obsidian artifacts found in archaeological sites of Western and Central-Western Honduras. The possible role played by some of the most important rivers of Guatemala and Honduras as waterway networks of transport was finally pointed out. New INAA chemical data from the Honduran obsidian source of La Esperanza (“Los Hoyos”, 4 samples) are also reported in this paper.

Les affleurements d’obsidiennes du Nemrut (Anatolie orientale) : mise en évidence d’une source exploitable, premiers résultats

Dans de nombreux sites du Proche-Orient, des artefacts archeologiques en obsidienne ont ete retrouves et attribues aux sources geologiques du Nemrut. Les publications sur la geologie du Nemrut montrent que des affleurements d’obsidienne sont presents sur les flancs sud, est, ouest et nord du volcan. Lors de deux missions de terrain (2013, 2014), nous avons prospecte une large partie du volcan et repere les affleurements decrits dans la litterature ; notre prospection n’a cependant pas ete exhaustive. La grande majorite des obsidiennes etudiees presente en effet un facies a phenocristaux et craquelures marquant une pietre qualite pour la taille. De plus, une grande partie de ces obsidiennes affleure sous forme de lits de faible epaisseur, ne permettant pas leur exploitation. Nous avons localise un seul affleurement d’obsidienne taillable. Associe a un atelier de taille, son facies, tres different de celui rencontre ailleurs dans le volcan, est uni et homogene, sans phenocristaux ni craquelures. Ces caracteristiques sont compatibles avec la taille pour la confection d’objets. Cet affleurement n’a jamais ete decrit dans la litterature. Comparativement aux autres affleurements d’obsidienne connus aujourd’hui, nous pouvons affirmer que cet affleurement d’obsidienne homogene est le seul taillable connu sur le volcan Nemrut. A partir des donnees de terrain, de l’etude des facies, d’analyses chimiques en LA-ICP-MS et d’une etude petrologique, nous pouvons emettre deux hypotheses concernant les modalites de mise en place d’un affleurement exploitable repere. Ces modalites en effet ont un rapport etroit avec l’accessibilite de la ressource et de ces espaces pour l’homme de la Prehistoire (du Paleolithique au Chalcolithique).

New Data on the Exploitation of Obsidian in the Southern Caucasus (Armenia, Georgia) and Eastern Turkey, Part 1: Source Characterization

A large analytical programme involving both obsidian source characterization and obsidian artefact sourcing was initiated recently within the framework of the French archaeological mission ‘Caucasus’. The results will be presented in two parts: the first part, this paper, deals with the presentation and characterization of obsidian outcrops in the southern Caucasus, while the second presents some results obtained from a selection of artefacts originating from different Armenian sites dated to between the Upper Palaeolithic and the Late Bronze Age. The same analytical method, LA–ICP–MS (laser ablation inductively coupled plasma mass spectrometry), has been used to characterize all the studied samples (both geological and archaeological). This method is more and more widely used to determine the elemental composition of obsidian artefacts, as it causes minimal damage to the studied objects. We present in this first part new geochemical analyses on geological obsidians originating from the southern Caucasus (Armenia, Georgia) and eastern Turkey. These data enhance our knowledge of the obsidian sources in these regions. A simple methodology, based on the use of three diagrams, is proposed to easily differentiate the deposits and to study the early exploitation of this material in the southern Caucasus.

Non-destructive PXRF analysis of museum-curated obsidian from the Near East

Non-destructive pXRF has the potential to expand sample populations of archaeological provenancing studies by facilitating access to museum collections of artefacts. In this study, we use museum-curated obsidian for the sites of Tell Brak, Mersin-Yümüktepe and Tell Arpachiyah and geological obsidian samples from central Turkey to demonstrate that non-destructive pXRF is comparable to other techniques in differentiating between Near Eastern obsidian sources. Secondly, we use multivariate analysis to evaluate whether non-destructive pXRF is sufficiently accurate and precise to enable comparison with legacy datasets from previous analysis using PIXE and ICP-MS. Multivariate analyses show that instrumental offsets between the results from pXRF and other analytic techniques are less than source-to-source variation typical for most Anatolian obsidian outcrops and pXRF-identified geochemical groups are directly comparable to legacy datasets. Non-destructive pXRF analysis indicates that during the Chalcolithic, East Göllü dağ and Nenezi dağ continued to be the major sources of obsidian to communities in central Anatolia and the Bingöl range and mountains surrounding Lake Van supplied sites east of the Levant. Variations in the analysed assemblages suggest a number of obsidian exchange networks existed during this period.

New investigations of the Göllüdağ obsidian lava flows system: a multi-disciplinary approach

The Göllüdağ obsidian lava flow system is relatively complex. More than ten different obsidian outcrops and knapping workshops have been identified around this volcano. Their importance for long and short distances obsidian supply has already been demonstrated. One of the main problem encountered when studying the Göllüdağ obsidian flows, is the great chemical similarity of some of them. The use of the geochemical approach to solve the problems of obsidian trade around the Göllüdağ is therefore insufficient. A multi-disciplinary program joining archaeology, geochemistry and geomorphology, was thus started to understand the relationships between the different obsidian flows and to draw the pattern of the Göllüdağ obsidian trade. Our archaeological and geomorphologic approach will help us to understand which obsidian outcrops were available during the Palaeolithic and Neolithic periods. Also our geomorphologic approach, linked to intensive geochemical analyses, will help us to understand the spatial variability of the geochemistry of the obsidian outcrops. Lithic technology will also give information about the different knapping methods used at the workshops.

Increasing data (INAA) on Ecuadorian obsidian artifacts: preliminary provenance and a clue for pre-Columbian eastward trade

In this work we carried out INAA major (Na, K, Ca and Fe %) and trace (ppm) elements (plus Mn by FAAS analysis) of 15 obsidian samples (waste flakes) coming from an unknown archaeological site ( 14C-AMS age of 1425 AD) located on the south-eastern flank of the back-arc Sumaco volcano (to the east of the Cordillera Real) and from two already known pre-Columbian archaeological localities: La Florida (Quito) and Milan (Cayambe). Literature compositional data of the Ecuadorian obsidian outcrops provide some constraints on the provenance of the analyzed waste flakes, even though different methods of analyses make comparisons a difficult task. Concerning the obsidian artifacts of La Florida and Milan, they come from the well known Sierra de Guamanì obsidian sources (Cordillera Real). By contrast, the obsidian fragments of the Sumaco settlement show some compositional characters compatible with obsidian erratic pebbles recently discovered in some river banks of the Amazonian foothills draining the easternmost flanks of the Antisana volcano in the Cordillera Real as well. In this way, the obsidian artifacts found at the Sumaco site reinforce the opinion that Ecuadorian source inventory is not yet exhaustive. Although the Antisana volcano seems to be the best candidate to find out additional primary outcrops of obsidian sources, it cannot be also excluded that sub-Andean and Amazonian people directly took advantage from obsidian secondary sources (e.g. river banks), rather than procurements from primary outcrops in the Cordillera Real. The new archaeological findings at the Sumaco volcano are really of paramount importance in tracing the ancient routes of a possible obsidian eastward trade toward the Amazonian region.

Is Obsidian Hydration Dating Affected by Relative Humidity?

Experiments carried out under temperatures and relative humidities that approximate ambient conditions show that the rate of hydration of obsidian is a function of the relative humidity, as well as of previously established variables of temperature and obsidian chemical composition. Measurements of the relative humidity of soil at 25 sites and at depths of between 0.01 and 2 m below ground show that in most soil environments, at depths below about 0.25 m, the relative humidity is constant at 100%. We have found that the thickness of the hydrated layer developed on obsidian outcrops exposed to the sun and to relative humidities of 30-90% is similar to that formed on other portions of the outcrop that were shielded from the sun and exposed to a relative humidity of approximately 100%. Surface samples of obsidian exposed to solar heating should hydrate more rapidly than samples buried in the ground. However, the effect of the lower mean relative humidity experiences by surface samples tends to compensate for the elevated temperature, which may explain why obsidian hydration ages of surface samples usually approximate those derived from buried samples.

Mountain of glass: Archaeology of the Mount Edziza obsidian source, British Columbia, Canada

Abstract Results of a first‐stage archaeological reconnaissance of the Mt Edziza obsidian source area in northwestern British Columbia, Canada, are described. Mt Edziza obsidian has been utilized by native people for 9–10,000 years and widely distributed throughout surrounding regions. Archaeological investigations reveal primary concentrated obsidian outcrops and quarry sites at high elevation, as well as lower and more dispersed areal scatters of raw material. Preliminary excavation results and paleoenvironmental reconstructions suggest that the concentrated alpine obsidian sources were probably most intensively exploited prior to 3000 B.P. and the onset of cooler Neoglacial climates. Site ‘trains’, or series of functionally differentiated workshops and campsites are distributed around the primary obsidian sources at lower elevations near the tree‐line. Many of these sites appear to have emphasized manufacture of ovate biface‐preforms as the main form in which obsidian was redistributed beyond the mount...