ARCHAEOLOGICAL AMBERS FROM NORTHERN ITALY: AN FTIR–DRIFT STUDY OF PROVENANCE BY COMPARISON WITH THE GEOLOGICAL AMBER DATABASE*

European geological ambers of five different localities and types, and Italian geological ambers from seven different deposits have been studied with Fourier transform infrared spectroscopy (FTIR) and diffuse‐reflectance infrared Fourier transform (DRIFT). Ambers from several localities have been characterized for the first time. The research aims to create a database of European ambers, containing both FTIR and DRIFT data. The FTIR spectra are easily comparable with the data commonly available in the literature, whereas DRIFT analyses are shown to be more useful to characterize the archaeological finds. The provenance of several archaeological ambers from northern and southern Italy, dating from the Middle Bronze Age to the Iron Age, is assessed on the basis of the developed database. Of the 35 analysed archaeological objects, all but five are composed of Baltic succinite amber.     

The chemical identification of baltic amber at the Celtic oppidum Staré Hradisko in Moravia

The Celtic oppidum Staré Hradisko north of Brno in Moravia, SSR, has long been noted for its wealth of archaeological amber artifacts. Since there are several substantial deposits of fossil resins in the immediate vicinity of the site, it has been an open question whether the settlement was a centre of exploitation and exportation of these local raw materials, or whether it was an entrepôt of Baltic amber on its way to southern and southeastern Europe.Because of extensive weathering, many of the amber finds at Staré Hradisko cannot be identified by infra-red spectroscopy. A new analytical method, which determines the amount of succinic acid by means of gas chromatography, has been developed to show that the amber of Staré Hradisko is, in fact, of the Baltic variety called succinite.     

Local amber in a Palaeolithic context in Cantabrian Spain: the case of La Garma A

It is important to determine the geological sources of Palaeolithic ambers in the south of Europe in order to understand the mobility and interchanges of prehistoric societies. Fourier transform infrared (FTIR) spectroscopy analysis carried out on Upper Palaeolithic ambers from La Garma A cave (Cantabria, Northern Spain) allowed us to identify their source area. Their diagnostic features were found to be similar to the amber obtained in the Lower Cretaceous outcrops close to this archaeological site, and to differ clearly from Baltic amber, which has been generally suggested as the amber found in European prehistoric sites. These results show that the origin of the Gravettian amber found in La Garma A is local and, consequently, a hypothetical contact route is not required to be able to account for the presence of this material in the Iberian Palaeolithic context studied here. For the first time it has been demonstrated that the provenance of an archaeological amber in the Iberian Peninsula is local, with both geographical and spectroscopical evidences. Our study also concludes that the archaeological amber of La Garma A possibly belongs to an araucariacean resin that originated from the coniferous forests which grew in the northeast portion of the Iberian Plate c.110-million years ago.     

The use of different amber sources in Italy during the Bronze Age: new archaeometric data

The production of amber ornaments occurred in Italy during the Eneolithic (E)–Early Bronze Age (EBA), although very few beads from the Italian peninsula have been found and analysed. The number of data available for provenience study of Bronze Age ambers is larger, but still a precise picture of when and to what extent the local sources of amber were exploited is lacking. In the present work, 22 amber finds from six Sicilian sites have been studied and analysed by infrared spectroscopy, in particular with DRIFT (diffuse reflectance infrared Fourier transformed) analyses. The amber samples are dated between the Eneolithic and the Final Bronze Age–Early Iron Age and are from the collections of the P. Orsi Museum, in Syracuse (Sicily). The data show that only simetite was used in South Italy in the Late Eneolithic (LE)–EBA. In the Bronze Age, the exploitation of simetite shows different intensity in different chronological phases. The results are discussed in comparison with the information available for coeval European ambers.     

Classification of the Amber Beads of the Hungarian Bronze Age

Abstract

Spectroscopic provenance analysis of Hungarian amber artifacts has shown that nearly all of them are of Baltic amber or succinite, which occurs naturally only in northern Europe. The present paper explores the question whether these beads were made in northern Europe and imported into Hungary as finished products, or were made in Hungary from imported raw material.

To this end, 659 extant amber beads of the Bronze Age of Hungary are divided into 17 types by shape and dimensions. The significance of the typology is borne out by striking diachronical patterns: e.g., flattened globular beads (Group III) are virtually limited to the Middle Bronze Age, while truncated bi-conical beads (Group IX) are essentially exclusive to the Late Bronze Age. By comparing Hungarian bead forms of a given period with those of countries to the north, including Denmark and the Baltic States, the classification offers a means by which imported beads may be distinguished from locally made beads.     

DISTINGUISHING AMBER AND COPAL CLASSES BY PROTON MAGNETIC RESONANCE SPECTROSCOPY

Fossilized resin, or amber, has been examined from 120 worldwide sources by 1D and 2D proton magnetic resonance spectroscopy in solution. These spectra fall into five categories, corresponding to the classes already established by mass spectrometry and carbon‐13 magnetic resonance spectroscopy. The wide availability of this technique provides a straightforward method to classify amber rapidly and inexpensively.     

AMBER FROM THE DOMINICAN REPUBLIC: ANALYSIS BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

The carbon-13 NMR spectra of amber from several mining sites in the Dominican Republic show considerable variation. In certain cases the differences are sufficiently distinct to serve as a reliable indicator of provenance. The gradations within the resonances of unsaturated carbons may reflect the relative ages of the samples, because fossilization and diagenesis can remove this functionality.     

NUCLEAR MAGNETIC RESONANCE CHARACTERIZATION OF CRETACEOUS AMBER

Carbon-13 nuclear magnetic resonance spectra have been examined under high resolution conditions for 31 samples of fossil resin that have been dated to the Cretaceous period. Samples from Alaska, Canada, parts of the United States, Greenland, France, Switzerland, Lebanon, Jordan, and Israel have very similar spectra, consistent with a common, geographically dispersed palaeobotanical source. Samples within this large group exhibit a variation in spectral linewidth that is consistent with differences in sample age or maturity. A single Triassic sample from Bavaria shows the same spectral patterns but greater linewidths, indicating that it probably had a similar palaeobotanical source.     

THE AMBER OF EL DORADO: CLASS IB ARCHAEOLOGICAL AMBERS ASSOCIATED WITH LAGUNA GUATAVITA*

Laguna Guatavita, a crater‐like lake located in central Colombia, was used by pre‐Columbian Muisca people for a variety of socio‐religious ceremonies, many of which involved casting offerings into the lake. Of these, the installation of a new ‘king’ became the basis of the El Dorado myth that was carried back to Europe by 16th century conquistadores. In the present study, beads collected from Laguna Guatavita during a late 19th/early 20th century attempt to recover valuables from the lake bed, have been subjected to geochemical analysis. Results establish that these artefacts have been fabricated from Class Ib amber. Class Ib ambers have not previously been reported in either the geological or archaeological records of Central or South America, and their existence in this context implies that the Muisca people had access to a unique local or regional source of amber, knowledge of which has subsequently been lost.     

The Resinous Cargo of the Java Sea Wreck

A number of blocks of resinous materials were found in the cargo of a 12th‐ to 13th‐century shipwreck, discovered in the late 1980s in the Java Sea near the Indonesian islands of Sumatra and Java and excavated in 1996. These well‐preserved blocks presumably were trade materials used for religious, medicinal, cosmetic, decorative or practical purposes. Such materials, derived from plants and termed exudates, generally include frankincense, myrrh, ‘gum benjamin’, liquidambar, dragon's blood, dammar, copal and amber. The source of the cargo resin could not be determined from the site. Investigation by nuclear magnetic resonance (NMR) spectroscopy has revealed that the molecular structure corresponds to that of modern resin from the plant family Dipterocarpaceae, known in trade as dammar and closely resembling Group B copal and amber. Other molecular classes of exudates are excluded. Such materials are not present in the Middle East, which then cannot be their source. The NMR spectra differ from those of Group B samples from Australia, Papua New Guinea and Indonesia, but resemble those from India or Japan. The spectra indicate that the saline environment had a similar effect on the molecular structure to heating and aging.     

Roman amber identified as Siegburgite

A small amber fragment from the period of Roman occupation of Numantia (Garray, Spain) was characterised by Fourier transformed infrared spectroscopy and optical microscopy. The material was found to be a polystyrene-like material, which is a very rare fossil resin known as Siegburgite or class III amber. Until now, this material was found in Europe only at two sites, both localised in Germany, and it is the first time that this type of amber was identified in wrought archaeological artefacts. The discussion includes the applicability of the method to distinguish false from true and amber of different origins, its use and trading as well as a hypothesis for a transport route. The study highlights the need for a more systematic study of archaeological amber remains. The finding also proves the exploitation and trading of local, non-Baltic amber deposits throughout the Roman Empire.     

Preservation assessment of Miocene–Pliocene tooth enamel from Tugen Hills (Kenyan Rift Valley) through FTIR,chemical and stable-isotope analyses

We investigated fossil tooth enamel of mammals and crocodiles from two Mio-Pliocene East-African formations (Lukeino and Mabaget Fms) using infrared spectroscopy and chemical and stable-isotope analyses. Infrared spectra indicate that the fossil enamel contains biological apatite (bioapatite), without significant secondary carbonate contaminations. Several empirical infrared indexes were used to analyze the crystal–chemical characteristics of enamel. Fossil enamel has less organic matter, water and structural carbonate of apatite than modern enamel with which it was compared. Fossil apatite has a better crystallinity than bioapatite. The calcium/phosphorus mass ratio and the fluorine content of fossil apatite show intermediate values between bioapatite and geological fluorapatite. The samples also display significant crystal-chemical variations, depending on the vertebrate group (mammals vs. reptiles) and the taphonomic context (Lukeino Fm vs. Mabaget Fm). In spite of these changes, no relationship was observed between the chemical contents (carbonate and fluorine) and the stable-isotope ratios of carbonate (δ¹³C and δ¹⁸O) in fossil enamel. Preservation of the palaeoenvironmental signals is strongly supported by the fact that the stable-isotope composition of the three investigated fossil mammalian taxa (deinotheres, equids and hippos) is consistent with their ecological features. For instance, typical C₃- and C₄-plant isotope compositions are reflected in the deinotheres and equids, respectively, and amphibious hippos display lower δ¹⁸O values than terrestrial herbivores, as expected.     

THE PROVENANCE AND COAL RANK OF JET BY CARBON-13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

The carbon-13 nuclear magnetic resonance spectra of jet samples from England and Spain resemble those of carbonaceous materials from lignitic and sub-bituminous ranks. This characterization is based on the aromatic/aliphatic ratio of resonances and on the pattern of fine structure. Particularly characteristic of jet is the well-defined fine structure in the aromatic region that may be attributed to phenolic functionalities. This fine structure is found in all English and Spanish samples. Resonances from rapidly moving methyl groups are found in English but not in Spanish samples and may provide a means of distinguishing provenance.     

The Effect of Accelerated Alteration on the Discrimination between Baltic and Romanian Amber

Ten geological samples (five from each source—Romanian amber and Baltic amber) in duplicate for five different media (air, water, saline, acid and basic) were subjected to thermal alteration at 80 ± 2°C for 12 weeks, in the dark. The samples were analysed before and after the accelerated alteration experiment by Fourier transform infrared spectroscopy, both in transmittance and reflectance mode, and the acquired spectra were statistically processed by multivariate data analysis, mainly using principal component analysis. The results of the experiment are useful in giving a better picture of how to discriminate between archaeological amber artefacts.     

Modern and fossil charcoal: aspects of structure and diagenesis

The structures and compositions of modern and fossil charcoal samples were compared in order to evaluate charcoal degradation processes in archaeological sites. Modern charcoal samples produced in campfires contain two major phases: graphite-like microcrystallites and a non-organized phase. These phases create a mosaic-like structure with differing relative proportions depending on the taxonomic source of the wood used. Fossil charcoal samples (Tel Dor, Israel: 3000 years BP and Kebara Cave, Israel: 40,000 years BP) also contained the graphite-like microcrystallites and the non-organized phases, but were clearly altered compared to modern charcoal. The graphite-like phase of the fossil charcoal has much higher electrical resistivity, and its ESR properties show that it has markedly altered surface electronic states. Infrared spectra show the presence of additional carboxylate groups. Oxidation has therefore altered the structure. This appears to be a “self-humification” process that affects the graphitic component, and probably the non-organized phase as well.     

FTIR and statistical studies on amber artefacts from three Romanian archaeological sites

In the present study Fourier transform infrared spectroscopy in the reflectance mode (FTIR-reflectance) – was performed on well preserved archaeological amber, originating from three Romanian archaeological sites of Roman and Byzantine cultures, which did not allow sampling material. Resulting spectra were subjected to multivariate data analysis (MDA) using Principal Components Analysis (PCA). In the light of the FTIR-reflectance bands of archaeological samples from the region 1275 to 1155 cm⁻¹ and 900–600 cm⁻¹ we could conclude that the samples from first two locations, Ro?ia Montan? and Nuf?ru, are made from amber of Baltic origin. In the case of the third location, Isaccea, we take into account the possibility of a mixture of raw materials, both Baltic and Romanian amber. These assertions are supported by statistical analysis and the historical context. Besides the FTIR spectra comparison or other analytical data, it is very important to correlate any information about the material (colour, conservation status, historical context, connections with other artefacts) and the statistical analysis in order to favour safe conclusions.     

First fossil thaneroclerid beetle from mid-Cretaceous Burmese amber (Coleoptera: Cleroidea: Thanerocleridae)

Cai, C. & Huang, D., January 2018. First fossil thaneroclerid beetle in Upper Cretaceous Burmese amber (Coleoptera: Cleroidea: Thanerocleridae). Alcheringa 42, 115–119. ISSN 0311-5518.

Thanerocleridae is a small family of Cleroidea with no fossil representatives to date. Here we describe and figure the first fossil representative of Thanerocleridae, Cretozenodosus fossilis gen. et sp. nov., from the mid-Cretaceous amber of northern Myanmar. Cretozenodosus is referred to the extant subfamily Zenodosinae as evidenced by its open procoxal cavities and transverse procoxae. Cretozenodosus has close affinities with the North American Zenodosus Wolcott, suggesting that modern Zenodosinae is probably a relict group. Our discovery of a new thaneroclerid genus from Burmese amber suggests that Thanerocleridae originated no later than the mid-Cretaceous.

Chenyang Cai [cycai@nigpas.ac.cn] Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China; Diying Huang [dyhuang@nigpas.ac.cn] State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China.     

成都光华村街唐墓出土琥珀的红外分析

我国古代先民很早就意识到琥珀的装饰和药用价值,汉代开始从西域引入琥珀,唐代时琥珀已比较常见。我国古代琥珀多为进口琥珀,琥珀产地分析可以反映中外文化交流情况。国内仅对私人琥珀藏品进行过分析,考古出土琥珀的科技分析尚未见报道。本研究通过红外光谱分析,判定成都光华村街低阶官员唐墓出土红色饰品为琥珀;再与若干产地的琥珀开展红外光谱对比,鉴定其产地为波罗的海地区。琥珀经过丝绸之路到达蜀地并为低阶官员所使用,足见唐代琥珀制品的盛行及当时国际贸易文化交流的盛况。     

NEUTRON RESONANCE CAPTURE ANALYSIS OF SOME GENUINE AND FAKE ETRUSCAN COPPER ALLOY STATUETTES*

The probability of nuclei capturing neutrons reveals sharp peaks, so‐called ‘resonances’, which occur at neutron energies that are specific for each element. These resonances are very suitable for analysing the elemental composition of objects. They are the basis of a new analytical method, ‘neutron resonance capture analysis’ (NRCA). This is a fully non‐destructive method, which is applicable to almost all stable isotopes, determines the bulk elemental composition, does not require any sample preparation and results in a negligible residual activity. Recently, NRCA has been applied in a study of a series of bronze statuettes, obtained from the National Museum of Antiquity in Leiden (NL).     

Bronze and Iron Age Amber Artifacts in Croatia and Bosnia-Hercegovina

Abstract

The question as to whether or not Yugoslavia played a role in the Bronze Age amber trade to Greece has traditionally been answered negatively because of the scarcity of amber finds in that country. Amber finds that have come to light as a result of more intensive exploration after World War II have been thought to be of local origin by some Yugoslav scholars. Spectroscopic analysis of 35 archaeological amber artifacts from the Yugoslav provinces of Croatia and Bosnia-Hercegovina of the Bronze and Iron Age shows 31 of them to be of imported Baltic amber. The finds are discussed in their archaeological and geographic contexts as a first step towards re-assessing the place of the Eastern Adriatic area in the southward movement of amber.