The identification of archaeological amber has been used in Iberian prehistory to evidence long-distance exchanges and engage Iberia in networks that connect western Europe with central and northern Europe. However, assuming a Baltic origin for these ambers is not usually supported by analytical data and numerous deposits are found in Spain, Italy, France, Germany, Austria, Switzerland, Hungary and Romania.
It was not until the start of the twenty-first century, paralleling scientific developments in instrumentation and methods, that systematic provenance analyses of Iberian amber were performed.
Pioneering analytical studies by Beck (Beck et al. 1964, 1965; Beck 1965) paralleled the first inventories of amber artefacts in Portugal (Ferreira 1966) and the increasing attention paid to amber finds in archaeological reports. Since then, analytical studies have relied strongly on infrared spectroscopy (FTIR), nuclear magnetic resonance and gas chromatography as ways to determine the botanical and geographical origin of amber (Stout et al. 2000). FTIR became the standard technique in archaeology and was the first technique capable of determining the Baltic origin of amber through the presence of a distinct feature in its infrared spectrum: the ‘Baltic shoulder’ (Beck et al. 1964, 1965, Beck 1965, 1982). However, the limits of this method appeared to be reached when i t proved less successful in distinguishing between non-Baltic ambers due to a misclassification of copal as simetite. Once that had been solved, the characteristic FTIR simetite spectrum was clearly determined (Beck and Hartnett 1993). In addition, the discovery of geological sources of amber within the Iberian Peninsula in the 1990s (Rovira i Port 1994; Domínguez-Bella et al. 2001; Álvarez Fernández et al. 2005; Delclòs et al. 2007; Peñalver et al. 2007; Cerdeño et al. 2012) has challenged the capabilities of this technique, broadened the range of possibilities and reinforced the dangers of assuming amber provenance without supporting analytical evidence. A further limitation stems from the relative scarcity of analytical studies and absolute dating.
The analysis of Iberian Peninsula amber artefacts is approached by considering their provenance, chronology, and, most importantly, their spatial relationship with other exotica. It signifies a great advance in this field, as it increases the number of analyzed artefacts to 156.
Anta da Capela
Anta da Capela is a medium size megalithic passage grave, poorly preserved. Most of the orthostats from the chamber were broken or displaced (some of them even before the excavation in the nineteenth century), and currently only two of them remain in their original position. The monument itself still preserves the passage and the mound, a feature which is still visible in the landscape.
The finds, deposited in the National Archaeological Museum (Lisbon), are represented by a typical Late Neolithic/Early Copper Age assemblage. The amber nodule (MNA 2006.74.68) studied here (See figure below) appeared together with an assemblage of c. 500 beads worked in slate, talc, muscovite, variscite (MNA 2003.74.67), ceramic and ivory.
The homogeneity of the votive assemblage, and its features, situates the use episodes of this monument between 3200 and 2800 BCE; the absence of elements no more recent than the second quarter of the 3rd millennium BCE indicate that the “exotic” materials at this monument (such as amber, ivory and even the variscite) are attributable to an occupation centred in the transition from the 4th to the 3rd millennium BCE (and the first centuries of the latter).
Anta Grande da Comenda da Igreja
Anta Grande da Comenda da Igreja, Montemor-o-Novo (CNS 616), is a megalithic monumental passage grave, with collective burials, in use from the late 4th millennium BCE to the first half of the 3rd millennium BCE.
First excavated in the late nineteenth century, it has been the object of several excavations in the course of the twentieth century. The recovered pottery assemblage is typical of the Iberian 3rd millennium BCE. The excavations recovered (among other findings) a set of beads of different shapes made from various raw materials, including a zoomorphic schist pendant, a blue glass bead (possibly Bronze Age), green beads (talc, muscovite and variscite), lignite beads, fluorite beads (one of them with reticulated decoration) and several amber beads of different typologies (MNA 985.52.1, 2000.21.5 and 2011.54.102) (See figure below).
It is located in the necropolis of Valencina de la Concepción settlement, one of the largest (c. 450 ha) and most remarkable sites in Copper Age Iberia. Architecturally, Montelirio is a tholos with a double chamber oriented on an east–west axis. The corridors’ sides as well as the chambers and the main corridor’s roofing were made of slate slabs, while the roofing of the two chambers was built with sun-dried mud.
The individuals buried in the chambers were found to be associated with an extraordinary set of sumptuous grave goods, the most notable of which is an unspecified number of shrouds, cloaks or clothes similar to that of the warrior princes in the Italian Orientalizing period (Negroni Catacchio 2007, 2011), made of hundreds of thousands of perforated beads and decorated with amber beads. All the calibrated dates lie roughly within the first half of the third millennium BCE.
These are not the only amber finds in the necropolis of Valencina de la Concepción; Tholos 10.042–10.049 from the PP4-Montelirio yielded a pommel made of simetite and a bead and La Pastora tholos an amber bead (Almagro 1962: 20) that is deposited in the Museo Arqueológico Nacional in Madrid.
Monte da Pena/Povoado da Pena/Tholos do Barro
Monte da Pena hill at Torres Vedras is the location of a corbelled vault tholos-type funerary monument known as Tholos do Barro (CNS 662). Madeira et al. (1972) points out that this area may have been used as a funerary space, while Schubart referred to it as a settlement (Schubart 1967).
The beads analyzed here (See figures above and below) were recovered by Trindade and deposited in the Museu Municipal Leonel Trindade and labelled as Monte da Pena. It is most likely that these beads were recovered in the area around the monument, and therefore refer to the Bronze Age necropolis.
Anta Grande de Zambujeiro
Anta Grande do Zambujeiro (CNS 62) is a monumental megalith with a long corridor, and a seven-orthostat polygonal chamber with slab roofing. At the end of the corridor, just before the chamber, a pillar supports the roofing. The entrance to the monument was preceded by an atrium and an enormous granite stele / standing stone.
Inside the chamber, the presence of microliths, variscite beads (Odriozola et al. 2012) and polished stone tools seems to date the first burials in the late 4th millennium BCE (Santos 2009: 62). These older levels were sealed by a fallen chamber slab overlain by a long 3rd millennium BCE occupational sequence. The most significant burial goods on top of this fallen slab are small decorated pottery vessels (Santos and Rocha 2015), arrowheads, engraved schist plaques, a gold foil and the amber beads (See figure below).
Chronologically, a radiocarbon date obtained from charcoal recovered in the tumulus excavations has given a calibrated date for the megalith that roughly spans the second half of the 3rd millennium BCE (Soares and SIlva 2010: 101).
The dramatic increase in number of amber artefacts during the Copper Age compared with the Neolithic, and the notable number and total weight of the Anta Grande do Zambujeiro amber bead assemblage, only paralleled by the Montelirio tholos assemblage (2900–2800 cal BCE), makes it plausible that the amber beads from Anta Grande do Zambujeiro belong to a very similar time.
Monuments 3 and 4 at Alcalar
The megalithic cluster of Alcalar, Portimão (CNS 11310, 4298, 3512, 7234, 7241, 7245, 11303, 7249, 7277, 7232, 7238, 6807, 7215, 33793, 33792) is mainly characterized by a central group formed by 15 monuments, with Alcalar 1 corresponding to a dolmen-type tomb, and the remaining monuments to corbel vault tombs (tholos-type) with different typologies. Other peripheral groups are associated with this central core, such as Monte Velho (three tholoi), Monte Canelas (four hypogea) and Poio (one possible tholos and a natural cave). All these extensive funerary areas are directly associated with an important Chalcolithic settlement, the ditched enclosure of Alcalar.
The first moment of use of this area as a funerary space could be established in the last quarter of the 4th millennium BCE, corresponding to the construction and first use of the dolmen of Alcalar 1 and the hypogeum of Monte Canelas 1. It could then be extended throughout the 3rd millenniumBCE, with the construction and first use of the corbel vault monuments (possibly still during the first half of the 3rd millennium) and their subsequent reuse (now in the second half).
The amber artefacts studied here (See figure above) were collected in monuments 3 and 4 at Alcalar, two tholos-type monuments with different architectural features.
Only two of the amber artefacts collected in these monuments correspond to beads, namely MNA 983.1007.77 (Alcalar 3) and MNA 983.1008.113 (Alcalar 4). The remaining elements, all fromAlcalar 3, refer to a small nodule (MNA 983.1007.103) and three “mushroom-shaped” artefacts (MNA 983.1007.74 to 76).
Cova del Gegant
Cova del Gegant (Sitges, Barcelona) is a cave located in the Garraf Massif (NE Iberian Peninsula), on the Cape of Punta de les Coves. Cova del Gegant is formed by a subterranean network of galleries, which includes Cova del Gegant and the adjacent Cova Llarga, to which it is connected by a very narrow passage.
The archaeological layer ascribed to the Bronze Age mainly corresponds to a collective burial radiocarbon dated to the Middle Bronze Age, 1600–1400 cal BCE. The artefacts recovered comprise Late Bell Beaker pottery (NR = 71) featuring a decorative style akin to the Northeastern Group, generally ascribed to the Early Bronze Age. Ornaments are scarce and consist of four shell-beads, three lignite-jet beads, two amber beads (See figure below), one coral fragment and one Cypraea fragment. Additionally, two gold artefacts known as tutuli have been recovered from the same archaeological horizon; these are very rare ornaments in the SW of Europe (Daura et al. 2017).
The 84 tombs in Los Millares necropolis (Afonso Marrero et al. 2011) display, according to Chapman (1990), some differentiation in terms of presence/absence of symbolic items and exotica made from rare raw materials such as amber.
Chronologically, Los Millares covers a time span ranging from the last quarter of the 4th millennium to the early 2nd millennium BCE. That covers the whole Copper Age period.
A total of 16 amber beads and fragments were recorded in five tombs: VII/7, IV/8, 12, III/63 and 74 (Arabic numerals correspond to the Siret-Leisner seriation and the Roman numerals to that of Almagro and Arribas).
Tomb 12 yielded five amber beads of different typologies and sizes, and a fragment. The most remarkable is a large barrel bead (1976/1/MILL/12/2), 4.7 cm long and decorated with parallel, incised lines along the perforation that are now inappreciable because of the degradation of the piece (4.5 × 2.10 cm). The Leisners (Leisner and Leisner 1943) also describe a bead fragment, two cylindrical amber beads (one with red pigment), a discoidal bead, and a “tear-shaped” amber pendant with V-shaped perforation.
A non-perforated amber flat-sphere (1976/1/MILL/63/1) was also found during Siret’s works in Tomb III/63. Similar examples of non-perforated amber objects have been found in Los Delgados I tomb. Nowadays, both pieces are exhibited in Museo Arqueológico Nacional in Madrid.
An amber bead was found in each of Tombs IV/8 (Almagro and Arribas 1963: 119–122) and 74 (Leisner and Leisner 1943: 24).
Tomb VII/7 is the only tholos of the megalithic tombs at Los Millares that has yielded amber.
Beads from Los Millares studied here (CE00845 and CE00846) (See figure above) are described as amber in the CERES catalogue, and were recovered by Almagro and Arribas in tomb VII/7, but no amber beads were said to be found during their excavations (Almagro and Arribas 1963). Instead, they refer to quartz beads.
Cueva de las Ventanas
Cueva de las Ventanas (Piñar, Granada, Spain) is a natural karst cave located in Sierra Harana. During rescue archaeological work under the supervision of Riquelme (Riquelme Cantal et al. 2001: 328), the bead studied here (See figure below) was found in association with two ‘Argaric’ inhumations in the 17-A sector of the cave.
This is the only amber find definitely associated with an individual in the Province of Granada for the whole Bronze Age.
Many of the finds deposited in the Museu Nacional de Arqueologia are isolated finds from nineteenth century local collectors or Vasconcellos’ excavations and no clear record of the amber bead (Fig. 11) studied here is given. Despite the Copper Age radiocarbon dates for this site, it is likely that this amber bead is from the Bronze Age due to 1) its typology, similar to that of Cabecinho de Capitoa (Sousa 2008), Moreirinhos and Senhora da Guia (Vilaça et al. 2002); and 2) the probable association with a Bronze Age metallic personal ornament assemblage (necklace, earring, button…).
Materials and methods
Since infrared spectroscopy is capable of satisfactorily distinguishing between Sicilian, Baltic, and Iberian Cretaceous ambers, copal… and can be performed either non-destructively, by means of attenuated total reflectance infrared spectroscopy (ATR-FTIR), or on a very small sample of no more than 1 mg, it has become the standard technique applied in archaeological research to determine the origin of amber artefacts. We have therefore followed this well grounded methodology to perform the study of 156 of the > 697 amber beads found at ten Iberian 6th-to-2nd millennia BCE sites, in order to investigate their origins and the internal homogeneity of the amber bead assemblages.
Results and discussions
None of the spectra show the so-called Baltic shoulder. Based on the registered FTIR spectra, an Iberian origin for this bead assemblage must be discarded.
Considering that the Montelirio tholos spectra match consensus spectra and reference patterns collected to date for simetite in the most diagnostically useful region (Beck 1971; Beck and Hartnett 1993; van der Werf et al. 2016), while the bands recorded here that are absent from the consensus spectra may be attributed to preservation issues, the most likely origin of this amber is Sicily.
Anta Grande do Zambujeiro, Anta da Capela, Anta Grande da Comenda da Igreja, Alcalar Monuments 3 and 4, and Cova del Gegant
The samples from Anta Grande do Zambujeiro, Anta da Capela, Anta Grande da Comenda da Igreja and Alcalar Monuments 3 and 4 yielded very similar spectra.
Like theMontelirio assemblage, spectra from Anta Grande do Zambujeiro, Anta da Capela, Anta Grande da Comenda da Igreja, Alcalar Monuments 3 and 4, and Cova del Gegant match consensus spectra and reference patterns collected to date for simetite in the most diagnostically useful region (Beck 1971; Beck and Hartnett 1993; van der Werf et al. 2016). Thus, the most likely origin of this amber is Sicily.
Cueva de las Ventanas
Cueva de las Ventanas FTIR spectrum shows the typical Baltic shoulder, therefore the Baltic origin of the amber used to manufacture this bead seems unquestionable.
Monte da Pena/Povoado da Pena/Tholos do Barro and Quinta do Anjo
In the diagnostic region, no recognizable amber pattern is seen. Both samples from Monte da Pena must be classified as macro crystalline ferruginous quartz instead of amber. The Quinta do Anjo bead is indeed another quartz artefact according to its chemical composition.
The two beads recorded as amber in the Museo de Almería’s database yielded the typical mica SWIR spectrum6 and chemical composition. Therefore, these beads have been characterized as yellow micas.
Iberian ambers from the 6th to 2nd millennia BCE
Even though an amber trade route cannot be established for the Iberian Paleolithic—all analyzed samples are identified as local Cretaceous ambers (Álvarez Fernández et al. 2005), a Mediterranean route may be proposed for the Neolithic Iberian ambers because all the finds, except for the three beads from Campo de Hockey, originated in Sicily. At the 5th–4th millennia BCE transition, when the amber trade is first documented in the Iberian Peninsula, the first alpine jade axe reaches the Iberian Peninsula (Cassen et al. 2012; Fábregas Valcarce et al. 2012) and the first exploitation of variscite deposits in the Iberian Peninsula starts (Odriozola et al. 2016b).
Just before the beginning of the 3rd millennium BCE, the number of ivory and variscite objects records exponential growth (Schuhmacher 2012; Odriozola et al. 2016b) that is paralleled by the number of amber finds, which grows spectacularly during 3rd millennium BCE.
During the first half of the 3rd millennium BCE, the amber route that had connected Sicily with the Iberian Peninsula since the 5th millennium BCE must have intensified its activity, as the number of finds increases dramatically from the former phase to this stage. The intensification of the activity associated with this Mediterranean amber route is also supported by the presence of an outstanding amount of Asian ivory associated with amber contexts in the PP4 Montelirio structure 10.042–10.049 (García Sanjuán et al. 2013) and in the IES ivory workshop at Valencina (Nocete et al. 2013). However, the Mediterranean route cannot have been the only route by which ‘elites’ were procuring exotic goods by this time. In the first half of the 3rd millennium BCE in Portugal, most of the ivory finds correspond to African elephants (Schuhmacher et al. 2009; Nocete et al. 2013), which could mean that a diversified exotica supply system was functioning in Iberia, even though all the analyzed amber has been characterized as Sicilian amber. For example, Anta Capela has yielded African elephant ivory beads (Schuhmacher et al. 2009).
Murillo-Barroso (2016: 330) suggests, at this point, that amber trade during this period of time was carried out through indirect trade with Sardinia and Tunisia, based on the obsidian trade (Tykot et al. 2013), ostrich eggshell, and especially on African ivory recorded at Valencina de la Concepción (Schuhmacher et al. 2009; Nocete et al. 2013). However, the only obsidian items from the Central Mediterranean (Monte Arci source) are dated in the 5th to 4th millennium BCE in northeastern Iberia (five blade blanks, plus a core: (Terradas et al. 2014), and no amber items are documented in Sardinia until the second half of the 2nd millennium BCE (Bellintani 2010; Angelini and Bellintani 2016). Nevertheless, we do agree that amber exchange networks must have reached the southern Iberian coast through North Africa, whereas northeastern Iberia participated in exchange networks that connected Southern France -from the Alps- with coastal Catalonia from the 5th millennium BCE, e.g. Alpine jade axe imports (Vaquer et al. 2012), and obsidian (Terradas et al. 2014).
A large number of amber finds are dated in the second half of the 3rd millennium BCE, with Anta Grande do Zambujeiro as the greatest exponent with > 168 Sicilian amber finds. The greatest difference with the first half of the 3rd millennium BCE is diversification in amber supply sources. Baltic amber is traded for the first time (Larrarte) and local Cretaceous amber is exploited again (Trikualtzi I and Cova de La Pastora). However, the use of Baltic and local Cretaceous amber is constrained to the northern and eastern Iberian Peninsula, while the south of the Iberian Peninsula is still supplied by the Mediterranean amber route that had been operating since the 5th millennium BCE.
By this time, Baltic amber finds record a noteworthy increase and reach their maximum expansion (associated with bell beakers) towards western Europe -Czech Republic, Western France, Great Britain, Holland and Austria (du Gardin 2002), including northeastern Iberia. This most likely implies that previous exchange networks in use since the 5th millennium BCE (Alpine jade axes) were still active, bringing Baltic amber to this region of Iberia, while at the same time Sicilian amber was reaching the southern Iberian Coast. This ‘French connection’, also supported by the arrival of Northern European pottery styles (‘pastillas repujadas’) and CZM Bell Beakers (Hurtado and Amores 1982, 1985), indicates links with northern Europe via the South of France (Murillo-Barroso and Martinón-Torres 2012: 209).
The diversification of supply systems have also been recorded in Italy, where simetite was solely consumed from the 4th millennium BCE to 1800–1600 cal BCE, when the pattern started to change and the first Baltic ambers are recorded in Northern and Central Italy and Sicily together with a large increase in the number of finds (Bellintani 2010; Angelini and Bellintani 2016). From this moment onwards all the Italian archaeological ambers were worked exclusively out of Baltic amber (Angelini and Bellintani 2016). However, by this time Greece had become the focal point of trade and ambers with different spectral signatures to that of succinite or simetite have been recorded, pointing to a very diversified and well established exotica supply system (Angelini and Bellintani 2016).
Nonetheless, during this procurement shift, the last simetites spread across the Mediterranean Sea, reaching Greece (Vayenas tholos, Pylos, Greece) c. 2200–1600 cal BCE (Middle to Late Heladic I-III) (Beck and Hartnett 1993; Angelini and Bellintani 2016) and the northeastern Iberian Peninsula (Cova del Gegant) c. 1600–1400 cal BCE.
At the same time as the Baltic Sea became the main amber supplier in the Mediterranean (1800–1400 cal BCE), the use of personal adornments made from Baltic amber established a new trading vector towards Central Europe (South of Germany), Southeast France (the Alps) and Greece, and almost disappeared from the Baltic Sea region, Western France and Great Britain (du Gardin 2002: 223).
(Source: “Amber, beads and social interaction in the Late Prehistory of the Iberian Peninsula: an update”, by Carlos P. Odriozola et al.)
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