Roman marble from Lusitania: petrographic and geochemical characterisation

This paper reports the results of an archaeometric study of the marble from the Estremoz Anticline, Portugal. Thirty-four samples from eleven different locations were analysed petrographically. In addition, ten samples were selected for trace element and strontium isotopic analysis. The sampling was aimed at obtaining material from known ancient quarries and at establishing the overall petrographic and geochemical variation of the marble from the Estremoz Anticline. The main type of marble in Estremoz is a white(-veined), calcitic marble with an average maximum grain size between 0.81 and 3.50 mm. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.70850 to 0.70891 and are similar to the results for other Palaeozoic marbles of the Iberian Peninsula.     

Consideration on the construction process and the sandstone quarries during the Angkor period based on the magnetic susceptibility

Detailed magnetic susceptibility measurement was conducted on the sandstones used for the Angkor monuments constructed in the period spanning the Preah Ko and Angkor Wat styles, and the construction process of the buildings and quarries of the sandstones was considered. Combined with the previous study on the sandstones of the Bayon style [Uchida, E., Cunin, O., Shimoda, I., Suda, C., Nakagawa, T., 2003. The construction process of the Angkor monuments elucidated by the magnetic susceptibility of sandstone, Archaeometry 45, 221–232], the magnetic susceptibility measurement revealed that there were 7 sandstone quarries corresponding to Stages I, II, III, IVa, V, VII and VIIIb during the Angkor period. The sandstones used for the monuments belonging to Stage I show average magnetic susceptibility values ranging from 1.1 to 2.3 × 10⁻³ SI units. In the Bakheng style period (Stage II), the average magnetic susceptibility of the supplied sandstones decreased gradually from around 10 to 1 × 10⁻³ SI units over time. The magnetic susceptibility range of the sandstones used for the monuments of Stage III was from 2.3 to 3.0 × 10⁻³ SI units. In the early Angkor Wat style period (IVb), the average magnetic susceptibility of the supplied sandstones increased over time, reflecting the supply of the sandstones from two different quarries, that is, the quarry corresponding to the Khleang and Baphuon style monuments (Stage IVa), with low average magnetic susceptibilities of 1.1 to 2.4 × 10⁻³ SI units, and the quarry corresponding to the main Angkor Wat style monuments (Stage V), with high average magnetic susceptibilities ranging from 2.8 to more than 4.3 × 10⁻³ SI units. The sandstones of Stage VII show low average magnetic susceptibility around 1 × 10⁻³ SI unit. The sandstones of Stage VId is a mixture of sandstones of Stages V and those of Stage VII. The sandstones with high magnetic susceptibilities are found in the monuments belonging to Stage VIIIb, reflecting the supply from the new sandstone quarry.     

Nature and provenance of the sandstone used for Bayon style sculptures produced during the reign of Jayavarman VII

Under Jayavarman VII (1182/83-ca.1218 CE) the Khmer empire reached its apex, leaving a heritage of major construction works and unique artistic production. The stone materials of several sculptures produced under his reign were characterized and compared to possible geological sources in northern and eastern Cambodia. The data suggest that a specific type of sandstone, rich in volcanic detritus, was deliberately selected and quarried from a Triassic sedimentary sequence exposed far from Angkor, the main political and economic center at that time.     

Salt weathering of sandstone at the Angkor monuments,Cambodia: identification of the origins of salts using sulfur and strontium isotopes

The Angkor monuments in northwestern Cambodia, which are primarily made of sandstone, are suffering from deterioration due to salt weathering. In order to elucidate the sources of the salts and salt weathering process, this paper analyzed bulk chemical compositions and S (sulfur) and Sr (strontium) isotopic ratios for the salts and surrounding environmental materials. At places where bats inhabit the structures, various kinds of sulfate and phosphate salts are formed on the surface of the sandstone. The results of the analysis demonstrate that the S and P (phosphorus) components in the salts are primarily derived from bat guano. Moreover, Ca (calcium), which is the major element in the salts, is suggested to be derived from both bat guano and the sandstone. The isotopic data strongly suggests that bat guano is related to salt weathering. Removal of these animal excrements is essential for future conservation of these monuments. On the other hand, exfoliation of sandstone commonly occurs due to crystallization of calcite (CaCO₃) on platform surfaces of pyramid-type monuments. A large amount of Ca in calcite is suggested to be derived from calcite cement of the building sandstone.     

Archaeometrical study of Khmer stoneware from the Angkorian period: Results from the Cerangkor Project

In the area around Angkor, Cambodia, several ceramics kilns dating from the ninth to 15th centuries ce have been discovered since 1995. The technical, typological and compositional characterization of their production has been one of the main goals of the Cerangkor Project. Samples of green‐glazed ‘Kulen‐type' stoneware and non‐glazed stoneware produced in five kiln sites in the Angkor region were analysed chemically by wavelength‐dispersive X‐ray fluorescence spectrometry (WDS‐XRF) and also petrographically. The data indicate that some workshops used similar raw materials for the same types of ceramics, suggesting the exploitation of the same geological formations in the whole region. Several references groups were established for each type of stoneware offering an important database for future provenance studies of sherds from consumption sites.     

New insights regarding the Akko 1 shipwreck: a metallurgic and petrographic investigation of the cannonballs

The Akko 1 shipwreck constitutes the remains of a small Mediterranean naval vessel, discovered in Akko harbour, Israel, and excavated over three seasons between 2006 and 2008. Among the finds at the shipwreck site were eleven cannonballs. Two of them, a 9-pdr and a 24-pdr, were retrieved and studied using metallurgical and petrographic methods. The examination of the cast-iron was performed with optical microscopy, SEM–EDS, XRF and microhardness tests. The remains of the casting sand from within the voids in both cannonballs were studied by petrography. Combined with the archaeological evidence and the historical background, the metallurgical and petrographic testing may suggest that Akko 1 was a warship or an auxiliary naval vessel of similar size to, or slightly smaller than, sixth rate, and was in Akko harbour circa 1840.     

INAA of pre-contact basalt quarries on the Samoan Island of Tutuila: a preliminary baseline for an artifact-centered provenance study

This project presents a material-centered instrumental neutron activation analysis (INAA) characterization of 120 geologic samples selected from four fine-grained basalt quarries on the Samoan Island of Tutuila. Previous attempts at definitive differentiation of these Tutuilan quarries have utilized x-ray fluorescence (XRF). In this study, clear differentiation of each analyzed quarry was achieved using INAA. Biplots of canonical discriminant analysis (CDA) scores for the INAA data illustrate clear separation based on the variation in chemical composition between each quarry. The samples analyzed not only define quarry separation, but also provide the “core group” for a preliminary baseline necessary for future artifact-centered provenance studies. Inclusion of these “core group” samples in the baseline was confirmed by stepwise discriminant analysis. These findings suggest the ability to determine artifact quarry of origin on the island of Tutuila, which can elucidate the importance of individual Tutuilan quarries in the production, distribution and consumption of fine-grained basalt artifacts in Polynesia.     

Trace elements in palaeopathology: Quantitative analysis of a case of hypertrophic osteoarthropathy by instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) of the bones of a 6th century case (AD ) of hypertrophic osteoarthropathy (HOA) showed high levels of Zn, Mn and K in the periosteal new bone. The concentration of Zn in the periosteal new bone appeared to be biogenetic in origin and connected with active mineralization processes in the abnormal bone tissue. Manganese and potassium concentrations were, at least partly, related to diagenetic processes.     

Developing baseline data to understand environmental change: a geochemical study of archaeological otoliths from the Coorong,South Australia

Otoliths are calcium carbonate structures found in the inner ear of teleost fish. While they are routinely studied by marine scientists, analyses of otoliths recovered from archaeological sites in Australia and the Pacific have generally been restricted to identification of species and sometimes the fish age. Otoliths can also provide information on the season of catch, and, through trace element analysis, allow the reconstruction of environmental conditions experienced by fish. In this study, we use otoliths from mid- to late Holocene aged archaeological shell middens at the Coorong (South Australia) to examine species present, season of catch, age of fish and environmental conditions experienced by fish. Results demonstrate that the majority of the fish (identified as Argyrosomus japonicus and Acanthopagrus butcheri) were caught in freshwater environments during the warm season, and had grown to an age and size indicative of their having reached sexual maturity. This study provides data indicating fluctuating levels of salinity in the estuary, which are significantly lower than the hypersaline conditions experienced today. Ultimately, this project highlights the usefulness of conducting more detailed investigations of otoliths, including geochemical analyses, to address a wide range of research questions in archaeology and palaeoenvironmental research.     

Archaeological carved slabs of the Langobard art in churches of Peligna Valley and Spoleto (Italy): provenance of the stones

In this study we investigate the provenance of the limestone and marble used to made carved slabs today placed in three churches located in Raiano and Vittorito (Peligna Valley, Abruzzo, Italy) and in Spoleto (Umbria, Italy). The slabs, representative examples of the Langobard art (Middle Ages), are dated approximately from 8th to 9th centuries A.D. and have the same pattern in terms of decoration, suggesting a progressive expansion of Langobards in central and southern Italy, after the foundation of the Pavia Kingdom.     

Provenancing the rhyolitic and dacitic components of the Stonehenge landscape bluestone lithology: new petrographical and geochemical evidence

The source of the bluestone component found in the Stonehenge landscape has long been the subject of great interest and considerable debate. The bluestones are a mix of lithologies, the standing orthostats being predominantly dolerites, variably ‘spotted’, with only four of them being of dacitic and rhyolitic composition and the Altar Stone being sandstone. However in the 1920s the spotted dolerites were sourced to outcrops which comprise tors in the summit regions of the Mynydd Preseli in north Pembrokeshire, west Wales. There were also speculations about the possible sources of the dacitic and rhyolitic components, ideas which were elaborated on in the early 1990s when the original petrological provenancing was supplemented by whole-rock geochemical analysis. Most recently, new petrographical investigations have been combined with zircon geochemical data to determine the possible source of one type of rhyolite, the so-called ‘rhyolite with fabric’, found abundantly as débitage in the Stonehenge landscape (but not composing the four orthostats) to outcrops in the vicinity of Pont Saeson, especially a large craggy outcrop called Craig Rhos-y-felin, located in low ground to the north of the Mynydd Preseli. In order to test this provenance whole-rock geochemical analysis has been undertaken on samples of débitage from the Stonehenge landscape and from the Pont Saeson area, including Craig Rhos-y-felin. These data are then compared with other new and existing geochemical data for dacitic and rhyolitic lithologies recovered from the Stonehenge landscape, including the four orthostats, as well as geochemical data from outcrops of the same lithologies from the two main volcanic horizons exposed across north Pembrokeshire, namely the Fishguard Volcanic Group and the Sealyham Volcanic Formation, both of Ordovician age. This study concludes that previous, 20th century, attributions of provenance to a number of dacitic and rhyolitic outcrops in the north Pembrokeshire have been in error whilst the new data for the Pont Saeson rhyolite accords well with elemental contents recorded in the ‘rhyolite with fabric’ lithology from the Stonehenge landscape débitage. This study therefore endorses the proposal that the Pont Saeson area is indeed the source of the ‘rhyolite with fabric’ lithology recovered from numerous sites in the Stonehenge landscape, and is the only reliable provenance for any of the dacitic and rhyolitic bluestone material collected to date. It also serves to endorse the use of zircon chemistry as a provenancing tool in archaeopetrological investigations.     

Gabbroic clay sources in Cornwall: a petrographic study of prehistoric pottery and clay samples

Summary.  This analysis of prehistoric pottery and clay samples from Cornwall demonstrates that the clay used to make Cornish gabbroic pottery in prehistory originated around the gabbro rock outcrop in a small area of the Lizard peninsula. The research uses petrographic and chemical analysis to subdivide the prehistoric pottery into six groups. Owing to the unusual geology of the Lizard these groups can be attributed to specific locations. The most abundant pottery fabric, Typical Gabbroic , was made using coarse clay which is mainly found in a 1 km² area near Zoar. A finer version of this clay, found higher in the soil profile or slightly transported and redeposited, was used to make Fine Gabbroic pottery and an even finer variant called FNS (Fine Non-Sandy) Gabbroic . We identify for the first time here a Loessic/Gabbroic pottery fabric which can be matched exactly to clay found at Lowland Point. Serpentinitic/Gabbroic pottery was made using clay from the gabbro/serpentinite border zone. Pottery made from the Granitic/Gabbroic fabric did not match any clay from the Lizard, showing that gabbroic clay was sometimes removed and made into pottery elsewhere in Cornwall. The main clay source near Zoar was used for clay extraction throughout the Bronze Age and Iron Age for pottery which was traded all over Cornwall. Other gabbroic clay sources produced pottery only during certain periods and exclusively supplied particular settlements, such as the Loessic/Gabbroic fabric which was found only at Gear and Caer Vallack. The results suggest that pottery was produced by several small-scale cottage industries, which may have operated on a seasonal, part-time basis and probably formed only part of a wide range of activities located around the Lizard area.     

Provenance study of early and middle bronze age pottery from Kaman-Kalehöyük,Turkey, by heavy mineral analysis and geochemical analysis of individual hornblende grains

The provenance of Early Bronze Age and early Middle Bronze Age pottery produced between 2100 and 1970 B.C. and excavated from Kaman-Kalehöyük, Turkey was studied using mineralogical methods, including heavy mineral analysis and geochemical study of individual hornblende grains. The relative abundances of heavy minerals in the fabrics of 20 Early Bronze Age (EBA) and early Middle Bronze Age (MBA) pottery sherds, together with 27 local sediments collected within a radius of 25 km of the site were studied. The heavy mineral distributions in the Kaman region were statistically analyzed for consistencies in their occurrence. Amphibole was found to be the most abundant heavy mineral in most of the analyzed samples, followed by titanite and epidote. The amounts of other minerals such as garnet, clinopyroxene, and zircon are subordinate. Different proportions of heavy minerals in the fabrics allow categorization of the EBA and early MBA potteries into 5 groups. Comparative study of heavy mineral assemblages of local sediments and pottery suggests that half of the EBA and most of the MBA potteries were produced from sediment near the excavation site, whereas the other half of the EBA potteries were produced from sediment occurring at 25 km east or more east of the site. The geochemistry of individual amphibole grains was studied by electron-microprobe analysis. Most of the studied amphibole grains are calcic and aluminous, corresponding to hornblende. They can be further characterized into four types based on their chemical composition. The combination of heavy mineral identity and hornblende geochemistry provides diagnostic evidence for the origins of Kaman-Kalehöyük pottery. These and analogous heavy mineral techniques are effective archaeometric tools for determining pottery provenance.     

Petrographic and geochemical investigations of the late prehistoric ceramics from Sos Höyük,Erzurum (Eastern Anatolia)

Ceramics from the late prehistoric periods at Sos Höyük, in Eastern Anatolia, located along a thoroughfare that connects the Trans-Caucasus, Iran and central Anatolia, were subjected to petrographic and X-ray fluorescence analysis in order to characterise the clay groups, with a view to determining provenance and production patterns. Dominated by Kura-Araxes Ware, the data from the sequence at Sos Höyük were compared with the previous studies from the neighbouring regions to understand commonalities in pottery production. The analyses reveal a local production of vessels, most probably for household use. Although Sos Höyük potters shared similarities in the procurement pattern of raw clays and production technique with their neighbours, differences can be also recognized.     

Slag inclusions in iron objects and the quest for provenance: an experiment and a case study

Slag inclusions are found within most archaeological bloomery iron artefacts and are remainders of slag created during the smelting and smithing processes. Although they are widely believed to provide data with the potential for provenancing iron artefacts, previous slag inclusion studies have mostly proven inconclusive. The main aim of the work reported here is to analyse experimental smelting and smithing assemblages (including ore, furnace lining, fuel and slag), to compare these to slag inclusions in the resulting bloom and worked objects, and then explore the relationships between ore, slag and slag inclusions. This study has revealed that the composition of slag inclusions most closely relates to the smelting slag produced, whereas provenance to a specific ore would be difficult due to the chemical variability derived from furnace lining, fuel and any fluxes used. Some compounds in the slag inclusions are particularly affected during smithing of the artefact, i.e. those present in the sand flux and fuel used. However, trends are observed in the K₂O/MgO, MnO/SiO₂, Al₂O₃/SiO₂, Al₂O₃/MgO, Al₂O₃/K₂O and Al₂O₃/CaO ratios that allow comparison between slag inclusions and smelting slag in these experiments, and may therefore be used during other provenancing attempts. The knowledge gained from the experimental assemblages was subsequently applied to an archaeological case study, examining objects from the 900 Cal BC smithing site of Tel Beth-Shemesh, Israel and the 930 Cal BC smelting site of Tell Hammeh, Jordan. The analyses suggest that none of the artefacts examined derived from the Hammeh smelting system.     

Lead isotope and metal source of Shang bronzes: a response to Sun et al.’s comments

In this brief response to Sun et al.’s ( 2018 ) comments on our paper, we re‐emphasize that archaeological, chemical and isotopic evidence are all relevant to the discussion about the metal source of the Shang period with highly radiogenic lead isotope ratios. The southern African bronzes have much lower lead contents and quite different lead isotopic signatures than the Shang bronzes. More importantly, there was no metallurgy of any kind in southern Africa before c.200 ce , so southern Africa cannot possibly be the source of Shang bronze, which date to about 1500 to 1000 bce .     

Provenance Analyses of the Volcanic Rock Grinding Stones from the Greek Colony of Selinunte,Sicily (Italy)—Constraints and Possibilities

The petrography as well as the major and trace element compositions of the Selinunte grinding stones, made of grey vesicular lava, were analysed. By comparison with geochemical data from volcanic rocks in the Mediterranean, we were able to determine that only a minor number of the tools were extracted from the nearest volcanics of Mount Etna and the Hyblean Mountains, while the majority of the grinding stones were most probably imported from the Aeolian Islands, although an origin from the Aegean cannot be excluded entirely. The results are important in order to scrutinize trading connections, especially for the earlier times of settlement during the sixth century bc .     

Geochemical provenance analyses of Roman lava millstones north of the Alps: a study of their distribution and implications for the beginning of Roman lava quarrying in the Eifel region (Germany)

In Roman times, rotary querns and different types of millstones, driven either by horse-capstan or water power, were produced in the lava quarries of the quaternary volcanic Eifel region and exported to many parts of the Empire. The geographic distribution of Roman lava millstones from the Eifel region provides important information about trade patterns and, in cases of well dated millstones, also allows an estimate as to when the Roman lava quarrying in the Eifel region began. Sixty-two millstones from Germany, France and Austria were sampled and analyzed for major and trace elements by X-ray fluorescence. To determine their provenance, the millstone data was evaluated by a combination of geochemical discrimination and cluster and discriminant analyses using an extensive and detailed database of all Roman lava quarries in the Eifel region. An Eifel provenance could be confirmed for forty-four artefacts and, furthermore, determined down to the exact lava flow. The affiliation of the other artefacts to other possible regions where millstones of comparable lava were extracted was carried out on the basis of geochemical data from the literature. However, because of insufficient data, only assumptions about the regional provenance can be made. The origins of the other finds are assumed to be the Vogelsberg region, the Massif Central, Orvieto, and, possibly, the Pannonian Basin. A preliminary map of the distribution of Eifel millstones in Roman times based on these data is presented; the beginning of Roman lava quarrying can be constrained to 8–7 BC.     

Petrographic Characterization and Provenance Determination of the Crystalline Marbles Used in the Roman City of Banasa (Morocco): New Data on the Import of Iberian Marble in Roman North Africa

This paper reports the results of an archaeometric study of the crystalline marbles used in the Roman city of Banasa (Morocco). On‐site surveys allowed a detailed inspection of the monuments of the ancient city and sampling of the different marble lithotypes used for architectural purposes and sculptures. The inventory was completed by the study of both the grey‐and‐white streaked or spotted marble items stored in the warehouse of the archaeological site and of those currently exhibited at the National Archaeological Museum of Rabat. Provenance determination of 28 samples was carried out by means of a multi‐method approach combining mineralogical–petrographic data and C–O stable isotope analyses as the first step, and cathodoluminescence microscopy as a complementary technique to verify possible unusual alternative origins of some marbles. The analytical results obtained were compared with both the most reliable international databases and the few available studies dealing with the use of marble in other Roman towns in Morocco (e.g., Volubilis, Thamusida and Sala‐Chellah). They point to a variety of classical marble sources such as Carrara, Mount Penteli, Paros, Marmara and probably Mount Filfila (Algeria), and prove a significant import of Iberian lithotypes.     

Celtic vitrified forts: Implications of a chemical-petrological study of glasses and source rocks

The term “vitrified forts” refers to remnants of stony fortifications of early Iron Age in which constituent rock fragments and boulders have been melted and/or welded together by heat, apparently in situ. The methods used are a matter of controversy, and even the question whether the firing was constructive or destructive is disputed. In this study we present bulk analyses of some twenty source rocks and of fifty glasses (in petrographic thin sections) from eleven sites and attempt to relate these data to the processes (and purposes) producing the observed sintering, welding and melting. The results are consistent with progressive partial, sometimes total, melting of the rocks used. In agreement with most previous investigators we conclude that no exotic rocks (although limited amounts of clays or organic debris cannot be excluded) were used as flux nor were easily fusible materials selected. On the other hand, simply burning an ordinary (of the later murus gallicus type) timber-laced wall cannot account for the evidence of strongly reducing conditions and sustained high temperatures, probably for days and in some cases well above 1000 °C. Rather, the fires seem to have been contained, perhaps by filling the space between the rocks in the timber framework with soil, clay and combustible materials, e.g. peat, brushwood and domestic debris. We cannot conclude whether the firing was accidental, or set by enemies or by the builders. In any case, the builders appear to have used more sophisticated techniques than previously believed to ensure the durability of their constructions.