eschweizerbart_xxx

Archaeometric characterization of Proto-Byzantine glass workshop from the

Roman amphitheatre of Catania (Sicily, Italy)

MARCELLA DI BELLA1, CARLOTTA GIACOBBE2, SIMONA QUARTIERI1, GIUSEPPE SABATINO1,* and UMBERTO SPIGO3

1 Dipartimento di Fisica e Scienze della Terra, Universita di Messina, Viale F. Stagno d’Alcontres 31, 98166 S. Agata,Messina, Italy

*Corresponding author, e-mail: gsabatino@unime.it2 ESRF, European Synchrotron, 71, Avenue des Martyrs, Grenoble, France

3 Soprintendenza dei Beni Culturali e Ambientali, Regione Siciliana, sezione di Messina, Viale Boccetta 38, 98100Messina, Italy

Abstract: Twenty-five glassy samples, including fragments of objects, molten glass and glass drops originating from a Proto-Byzantine glass workshop of the Catania Roman Amphitheatre, were analysed for major, minor and trace elements. Twomain groupsof natron-based silica–lime glass were identified, as well as one sample of obsidian (from Lipari Island). The majority of the samples(20) are High Iron,Manganese and Titanium (HIMT) glass. Specifically, most of them (18) can be classified as HIMT1, with only twoHIMT2 glasses, according to the latest classification proposed in the literature. Three samples belong to the Levantine I type. In regardto the geochemical signatures of HIMT raw materials, the high abundance of HREE relative to LREE and of HFS elements (Zr, Nb,Ta, Ti, Hf, Th), suggests the use of impure sand, particularly enriched in heavy minerals and/or in mafic phases. Furthermore, thenoticeably different contents of all the HFSE in the twomain sample sub-groups – enriched HIMT and depleted Levantine I – allow usto propose these elements as discriminating factors between the two glass categories, which were present at the same time.

Key-words: archaeological glass; Proto-Byzantine age; glass workshop; Catania Roman amphitheatre; EMPA; LA–ICP–MS;chemical analysis; provenance; archaeometry.

1. Introduction

The elemental composition of glass specimens reflects theraw materials and the techniques that were employed intheir manufacture. The geochemical analysis of glass cantherefore provide evidence on the origin of the raw materi-als, while the comparison of compositional data betweenarchaeological sites can potentially reveal patterns in theproduction and the glass trading. This can, in turn, shedlight on the economical and cultural connections linkingany one specific site to the wider world. Hence, the analy-tical study of archaeological glass can contribute substan-tially to our understanding of ancient technological andcultural processes.

In this paper we study glass remains from a glass work-shop recovered – together with ceramic artifacts – duringthe excavations at the Roman amphitheatre of Catania. Theindustrial setting is found at the site of a previous residen-tial district of the Republican and proto-imperial age, at thenorthern edge of the urban perimeter, above the escarp-ment that defines the northern boundary of the hill withrespect toMontevergine. The remains of the monument areonly partially visible and are overlain with the urban fabric

and construction of the eighteenth-century city, rebuiltafter the 1693 earthquake.

In the outer parts of the archaeological site, the two areasnamed IX and X were used both as entertainment placesand as work and residential spaces. In these areas relevantmaterials were found. The examination of the materials,particularly ceramics, allowed to date the remnants as Lateimperial and Proto-Byzantine (from the last decades of the4th to 6th century CE, with a higher percentage of potterydated to 5th century CE).

In the Late Roman–Byzantine age the glass composi-tion, which was almost constant for a long time in differentregions (i.e., silica–soda–lime glass typical of the RomanImperial Age), starts to change and differentiate, especiallyin regard to the minor components. In particular, the so-called HIMT glass, characterized by high levels of iron,manganese and titanium (Freestone, 1994), begins toappear in western European regions.

This work aims to provide new information on theSicilian glass production, up to now poorly studied,although Sicily was an important commercial crossroadof the Roman Empire. The chronological assignment ofthe glass samples is based on a precise study of the

‘‘Characterization, diagnosis andconservation of cultural heritage’’.School held in Catania/Siracusa,

1st to 4th July 2014

0935-1221/15/0027-2449 $ 4.95DOI: 10.1127/ejm/2015/0027-2449 # 2015 E. Schweizerbart’sche Verlagsbuchhandlung, D-70176 Stuttgart

Eur. J. Mineral. PrePub Article

PrePub DOI: 10.1127/ejm/2015/0027-2449

eschweizerbart_xxx

stratigraphic context and on the shape determination ofsome of the glass finds, most of which were classified asIsings 111 (Isings, 1957). To provide a chemical character-ization of the samples, selected glass fragments were ana-lyzed to determine their major and trace elementcomposition, using Electron Microprobe Analysis(EMPA) and Laser Ablation Inductively Coupled PlasmaMass Spectrometry (LA-ICP-MS). To better classify oursamples, the chemical data were also compared to thosefrom the literature concerning glass of the same age, butfrom different geographical areas. This work also aims todemonstrate the geochemical role of some trace elements(e.g., the high-field-strength elements (HFSE) Nb, Ta, Hf,Ti, Zr) in discriminating among different glass typologiesand different starting materials.

1.1. Archaeological setting

The Roman amphitheatre of Catania (Fig. 1) is found incorrespondence of a pre-existent Republican proto-Imperial village, located in the northern boundary of thecity, at the top of the Acropolis neighbouring theMontevergine escarpment. It is thought to have been builtin the second century, although the exact date is uncertain.The architectonic style leads back to the period intermedi-ate between the emperors Adriano and Antonino Pio. Theplan of the building shows an elliptical shape, with amaximum diameter of about 70 m and a minor one ofabout 50 m. It is leaning against the nearby hill, fromwhich it was separated through a corridor with large archesand vaults, which served as support for bleachers. Itsstructure could accommodate between 10,000 and 15,000seated spectators and probably many more standing. It was

filled with water to host the ‘‘naumachie’’, real navalbattles with ships and fighters. Its remains, representingless than a quarter of the entire amphitheater, are open tovisitors from the entrance of the Stesicoro Square and ViaColosseo. The remainder of the amphitheatre is still buriedunder the areas of Via Manzoni and Via Penninello(Leocata, 1999; Giordano, 2002; Sposito, 2003; Besteet al., 2007). Recent excavations have shown, mainly onthe basis of the diversity of masonry construction techni-ques, two main stages in the imperial age, the dating ofwhich is still in progress.

In the northeast sector of the amphitheatre, the outerportions of the second phase of construction, the so-calledIX and X areas were recognized. During the Late Imperialto Proto-Byzantine Age (second half of the 4th–5th centuryand the beginning of 6th century CE) these areas were re-used as workshop or habitations, as suggested by datedceramic finds (Beste et al., 2007). The same age is con-firmed by the finding of the installation of melting andprocessing shop of glass (Beste et al., 2007). This glassworkshop was located on a reddish clay soil characterizedby the presence of burnt patches and stones with clearindications of fire, which represent the remains of a fur-nace or of structures connected to it, testified also by thepresence of an iron receptacle and other fragments ofmetallic tools (Beste et al., 2007). In this glass workshopwere found large amounts of glass fragments many ofwhich are processing waste, fragments of recipient andmelting drops that represent the object of the presentstudy. This site is very important because it is believed tobe the second workshop for the production of glass everfound in Sicily, after the so-called ‘‘MansioPhilosophiana’’, 6 km to the south of the well-knownRoman Villa of Piazza Armerina (Enna, Sicily).

Fig. 1. (a) Roman Amphitheatre of Catania; (b) glasswork excavation site; (c) object fragments, molten glass and melt drops. (onlineversion in colour)

2 M. D. Bella et al. PrePub Article

eschweizerbart_xxx

1.2. Materials and analytical methods

The 25 glass samples studied in this work were provided bythe Soprintendenza BB.CC of Catania (Sicily, Italy) andinclude: 19 fragment of various objects such as cans,bottles, glasses, and cups (CT1, CT2, CT3, CT4, CT11,CT12, CT13, CT14, CT15, CT16, CT17, CT18, CT19,CT20, CT21, CT22, CT23, CT24, CT25); four samplesof molten glass (CT5, CT6, CT7, CT8), and two glassdrops (CT9, CT10). All samples were analyzed usingEMPA and LA-ICP-MS.

1.2.1. Electron-microprobe analysis

Wavelength-dispersive EMPA was used to determine theconcentrations of major and minor elements in all 25samples. The analyses were carried out on polished sam-ples using the ARL-SEMQ electron microprobe of theDepartment of Chemical and Geological Sciences of theUniversity of Modena and Reggio Emilia. The analyzedelements were Si, Al, Ti, Mn, Mg, Fe, Ca, Na, K, Sb, Cu,Pb, Sn, Co, Cr, Cl, and P, using the following geologicalstandards: BH3 albite (Na); A1D Springwater olivine(Mg); BH1 microcline (K, Al); A1P clinopyroxene (Si,Ca); azure sodalite with Cl (Cl), Durango apatite 104021Young et al. 1969 (P); BH7 ilmenite (Fe, Ti); BH5 spes-sartine (Mn); A3V cromite (Cr); cerussite (Pb). Metalliccobalt and metallic antimony were used for Co and Sbcalibration, and synthetic cassiterite, Cu94Sn6 alloy andsynthetic sulphide Pb4Ag6Sb6S16 were used for the cali-bration of Sn, Cu, and S.

The analyses were performed at 15 kV and 20 nA, with aspot size of 30 mm (to prevent the loss of light elementsunder the electron beam) and using counting times of 5, 10,and 5 s on background, peak and background, respectively.Twelve points were analyzed on each sample to test thehomogeneity, and the mean value of all the measurementswas calculated. The results were processed for matrixeffects using the PHI (rZ) absorption correction of theProbe program (Donovan & Rivers, 1990). The measuringaccuracy for the analyzed elements is better than 3 %,whereas the precision for major constituents is between 1and 2%, and for the minor constituents between 2 and 3%.

1.2.2. LA-ICP-MS

Trace element analyses were performed at the Departmentof Physics and Geology of Perugia University, with aThermo Electron X7 quadrupole based ICP–MS coupledwith a frequency quintupled (l ¼ 213 nm) Nd:YAG laser.The laser repetition rate and laser energy density on thesample surface were fixed at 10 Hz and �10 J cm�2,respectively. The analyses were performed using a laserspot diameter of 70 mm on the same polished samples usedfor EMPA analyses. Calibration was performed utilizingthe NIST SRM 612 glass as external standard and 29Si,previously determined by EMPA, as internal standard,following the method proposed by Longerich et al.(1996) and the analytical protocol described in Petrelliet al. (2008). The reference material USGS BCR2G was

analyzed to test the analysis quality. Precision and accu-racy were better than 7 % and 8 %, respectively (Petrelliet al., 2008).

2. Results

2.1. EMPA analyses of major elements

The results of EMPA analysis for major elements arereported in Table 1 and plotted in Fig. 2 and 3. Amongthe studied glasses, a natural obsidian (CT4) was alsoidentified. Its chemical composition is reported in Table1, but it will be discussed in the following separately fromthose of the archaeological materials.

The object fragments (CT1–CT3, CT11–CT25) are char-acterized by SiO2 contents ranging from 64 to 70 wt%,Na2O from 16 to 21 wt%, CaO from 5 to 9 wt% andAl2O3 from 2 to 3 wt%. The molten glass (CT5–CT8) andthe glass drops (CT9, CT10) show values of SiO2 rangingfrom 65 to 68 wt%, Na2O from 15 to 20 wt%, CaO from 5 to6 wt%, Al2O3 from 2 to 3 wt%. All samples are character-ized by low MgO (0.5–1.4 wt%) and K2O (0.3–0.9 wt%)contents. The only exception is represented by CT8, whichcontains much higher amounts of K2O (5.4 wt%).

In the K2O vs. MgO diagram (Fig. 2), which discrimi-nates between the use of natron or plant ash as the source offlux, the Catania samples plot on the field of natron-basedglass. Only the anomalous sample CT8 plots outside thisfield.

Table 1 shows that most of the Catania samples containhigh amounts of Fe, Mn, and Ti. Hence, to better discernthe nature of these specimens, additional diagrams (Fig. 3aand b) were used, which show compositional areas definedby Foster & Jackson (2009) for the HIMT group. TheHIMT typology was first recognized by Sanderson et al.(1984) and then named by Freestone after a study of rawglass chunks from Carthage (Freestone, 1994). Freestoneclassified glass varieties as HIMT when they were char-acterized by high levels of FeO (.0.7 wt%), MnO (usually�1–2 wt%) and TiO2 (.0.1 wt%), with a positive correla-tion between Fe and Ti, and a less strong positive correla-tion between Fe and Mn. Moreover, Foster & Jackson(2009) underlined the presence in this glass typology ofhigher soda (�18–19 wt%) and magnesia (usually .0.8wt%) and lower lime (�6 wt%) contents with respect tothose normally found in earlier Roman glass. Similar glasswas later identified at many sites across Europe: AugustaPraetoria, Group E (Mirti et al., 1993); Rome (Verita,1995); Modena (Arletti et al., 2005); the WesternMediterranean area (Foy et al., 2000); northern Sinai(Freestone et al., 2002a); Cyprus (Freestone et al.,2002b); the United Kingdom (Freestone et al., 2005); andGermany and Belgium (Aerts et al., 2003). ConcerningHIMT glass, Foy et al. (2003) and then Foster & Jackson(2009) provided a further discrimination between‘‘HIMT1’’ and ‘‘HIMT2’’, after a study of Late Romanglasses from Britain. These authors classified the two types

PrePub Article Proto-Byzantine glass workshop from Catania Roman amphitheatre 3

eschweizerbart_xxx

of glass on the basis of FeO, TiO2, MnO andMgO contentsand of some trace elements as Zr, Cr, Ba and Sr.

For a comparison, the data by Arletti et al. (2010) –relative to Byzantine glasses from Ganzirri (Sicily) – andby Conte et al. (2014) – relative to Late Antique glassesfrom Butrint (Albania) – are also reported in Fig. 3a and b.These two datasets have been selected since they providethe most comprehensive information on major, minor andtrace elements present in the literature for coeval HIMTand Levantine I glasses.

Specifically, the FeO vs. Al2O3 diagram (Fig. 3a) showsthat most of our glass finds (CT1–CT3, CT5–CT13,CT15–CT19, CT22, CT24, CT25) fall in the compositionalfields defined by Foster & Jackson (2009) for HIMT glass.In particular, strong affinity is seen between most of ourHIMT samples and the HIMT1 type of Foster & Jackson(2009), with only two samples (CT1 and CT22) showingmore affinity for the HIMT2 type. Three further samples(CT20, CT21, CT23) fall in the Levantine I area, identifiedfor similar compositions also by Foster & Jackson (2009).The TiO2 vs. FeO diagram (Fig. 3b) confirms that CT20,CT21, and CT23 samples have a Levantine I signature,while the other samples belong to the HIMT type.

2.2. LA-ICP-MS trace element data

Table 2 reports the LA–ICP–MS chemical data for HeavyRare Earth Elements (HREE), Light Rare Earth Elements(LREE), and other incompatible trace elements, like HighField Strength Elements (HFSE) and Large Ion LithophileElements (LILE). In general, the REE patterns, normalizedto upper continental crust (Wedepohl, 1995) show thatmost of the studied samples are enriched in HREE withrespect to LREE, and that only sample CT8 shows a flatterpattern (Fig. 4). The diagrams further illustrate the differ-ent abundances of REE in the two recognized groups,where specifically, HIMT (filled circles in Fig. 4a) areless depleted in REE with respect to Levantine I type(open circles).

Fig. 2. MgO vs.K2O classification diagram (in wt%). Fields are fromArletti et al. (2010).

Table 1. EMPA analyses (in wt%) of the studied glass samples.

Samples Type Colour SiO2 Al2O3 FeO MgO MnO CaO Na2O K2O TiO2

CT1 Object fragments light blue 69.94 2.14 0.77 0.75 1.26 5.00 19.26 0.39 0.22CT2 dark green 65.83 2.49 1.61 1.14 1.28 5.07 20.09 0.30 0.76CT3 light brown 66.66 2.45 1.20 1.00 1.35 5.47 19.45 0.39 0.48

CT4 Obsidian 75.95 12.57 1.27 0.01 0.02 0.60 3.96 4.46 0.09

CT5 Molten glass 66.22 2.58 1.25 0.85 2.23 5.47 19.02 0.86 0.41CT6 67.02 2.42 1.17 0.83 2.42 6.10 19.27 0.52 0.29CT7 67.68 2.57 1.18 1.12 1.51 4.59 19.52 0.74 0.38CT8 65.18 3.04 1.53 1.26 1.13 6.22 15.38 5.40 0.19

CT9 Drops light green 68.52 2.79 1.54 0.90 2.22 4.48 17.52 0.62 0.50CT10 light green 65.38 2.79 1.38 1.27 2.35 5.84 19.95 0.70 0.27

CT11 Object fragments green 64.67 2.53 1.08 1.02 1.06 6.23 19.73 0.40 0.46CT12 brown 65.25 2.43 1.18 1.29 1.33 6.79 20.21 0.48 0.33CT13 green 64.96 2.94 1.79 1.41 3.19 6.56 17.75 0.51 0.40CT14 light blue 65.91 2.82 1.58 0.97 1.88 5.76 17.73 0.54 0.58CT15 light green 63.58 2.57 1.55 1.18 0.46 7.86 20.63 0.47 0.54CT16 dark brown 64.11 2.37 1.35 1.03 2.12 7.39 20.07 0.51 0.32CT17 colourless 66.01 2.60 1.15 1.30 2.07 6.60 20.41 0.44 0.27CT18 green 66.04 2.42 1.33 0.99 2.10 6.51 19.11 0.48 0.42CT19 colourless 65.36 2.63 1.32 1.28 2.41 6.83 18.98 0.39 0.32CT20 light blue 69.63 2.84 0.32 0.50 0.04 8.80 15.82 0.85 0.04CT21 brown 68.45 2.92 0.38 0.62 0.89 8.54 16.32 0.57 0.07CT22 colourless 66.38 2.38 0.89 1.27 1.87 5.11 21.37 0.47 0.16CT23 dark green 70.35 2.83 0.41 0.69 1.26 7.16 16.07 0.68 0.05CT24 yellow-green 67.12 2.66 1.26 0.90 2.31 4.85 19.07 0.47 0.34CT25 green 66.88 3.05 1.71 1.35 2.81 4.82 17.42 0.49 0.41

4 M. D. Bella et al. PrePub Article

eschweizerbart_xxx

The concentrations of LILE and HFSE, normalized to theupper continental crust composition of Wedepohl (1995),are plotted in spider diagrams (Fig. 4d–f). All samples showhigh Sr and Ba and low Rb abundances, whereas some ofthe HFSE (Zr, Nb, Ta, Ti, Th, Hf) contents are in generalrather variable and particularly low in Levantine I samplesCT20, CT21 and CT23 (open circles in Fig. 4d). Table 2also shows that some of the HIMT glass samples are char-acterized by particularly high amounts of Cr. In regard toZr,,high values are shown by HIMT samples CT2 (527.72ppm), CT15 (497.55 ppm) and CT14 (439.92 ppm), butCT8 has a low content (97.39 ppm).

3. Discussion

As well known, natron was widely used in glass productionfrom the 9th or 8th century BCE up to the end of the 1stmillennium CE (Henderson, 1985; Nikita & Henderson,

2006). The reintroduction of plant ash technology isattested from the beginning of the 9th century CE(Henderson, 2013). The analytical data obtained for glassfinds from the Byzantine glasswork of Catania amphithea-tre plotted in Fig. 2 allow to classify all objects fragments,molten glass and glass drops as natron-based glass.

Additionally, the samples can be subdivided in twogroups, a HIMT group, which includes most of the samples(CT1–CT3, CT5–CT7, CT9–CT19, CT22, CT24, CT25),and the Levantine I type, which includes samples CT20,CT21 and CT23. Sample CT8 is distinct due to its anom-alous composition.

The questions regarding provenance and production ofHIMT glass are still debated by the scientific community.It is certain that this material was not abundant in theEastern region, whereas it was widely traded in theWestern Mediterranean area, which suggests that it wasnot produced on the Palestinian coast (Freestone et al.,2002b). Freestone et al. (2005) and Foy et al. (2003)have identified, for soda–lime glass from the 4th centuryand beyond, an Egyptian source for HIMT and a Syro-Palestinian source for the Levantine I type. RegardingHIMT, their hypothesis was based on the high Ti contentof their samples, which is common to Egyptian glass, andalso on the high soda content, which may indicate a raw-material location close to a natron source (Freestone et al.,2005; Leslie et al., 2006; Schibille et al., 2008) and a sandsource with mixed geological signatures originatingaround the Nile delta (Foster & Jackson, 2009).Concerning the production location of Levantine I glass,from the 4th century and beyond, it is thought to be inPalestine, and based on the use of sands from the Levantinecoast (Freestone, 2003; Foster & Jackson, 2009).

More recently, the provenance of raw materials forRoman glass production was investigated through the useof combined Sr and Nd isotopic analysis (Degryse &Schneider, 2008; Degryse et al., 2009). The glass isotopicdata were compared to the isotopic signatures of primaryglass from known production centres in the EasternMediterranean. As reported in Degryse et al. (2009),Levantine glass shows Nile-dominated Mediterranean143Nd/144Nd isotopic signature, with low Nd contents andhigh 86Sr/87Sr isotopic signature. Contemporary HIMTglasses have a similar 143Nd/144Nd isotopic signature,higher Nd content and a low 86Sr/87Sr signature. The simi-larity of Levantine and HIMT glass in terms of143Nd/144Nd and the fact that these values are similar toNile-dominated sediments, strongly suggest that HIMTglass comes from an area extending from the Nile deltanorthwards to the Levant (Freestone et al., 2003; Degryse& Schneider, 2008; Degryse et al., 2009).

Roman natron glass can be seen as a mixture ofthree components: silica sand, lime-bearing materialand natron as the soda-rich flux. All these raw materi-als introduced a number of trace elements to the glassbatch. Roman natron glass from 1st to 3th centuries CEis typically characterized by low content of trace ele-ments. This is attributed to the use of mineralogically

Fig. 3. FeO vs. Al2O3 (a) and TiO2 vs. FeO (b) compositionalvariation diagrams of the studied samples (in wt%). For a compar-ison, literature data by Arletti et al. (2010) and Conte et al. (2014) arealso plotted (see the legend for the adopted symbols).

PrePub Article Proto-Byzantine glass workshop from Catania Roman amphitheatre 5

eschweizerbart_xxx

mature sand, rich in quartz and relatively depleted inheavy minerals (Freestone et al., 2000, 2002b). Incontrats, HIMT glass typically contains higher

concentrations of trace elements, suggesting the useof less pure quartz sands (Freestone et al., 2005).Hence, trace-element analysis can help in identifying

Table 2. LA-ICP-MS trace element concentrations (ppm) in the studied glass samples.

(ppm)

Samples Sc V Cr Zn Ga Rb Sr Y Zr Nb Cs Ba La Ce Pr

CT1 2.28 17.8 6.8 18.25 2.32 4.10 483.33 10.31 143.39 3.41 0.07 351.58 8.94 12.97 1.89CT2 15.62 38.59 144.32 25.19 2.88 4.04 574.62 17.07 527.72 8.63 0.06 301.76 14.08 21.12 3.12CT3 2.62 34.80 17.28 26.15 2.78 4.47 751.9 14.75 317.06 6.17 0.07 568.80 12.18 18.35 2.70CT4 1.69 0.57 2.27 43.49 15.51 260.04 6.99 44.18 144.44 41.65 12.69 3.23 33.71 69.59 8.01CT5 2.79 32.69 20.43 22.16 2.88 3.81 713.07 13.07 257.79 5.67 0.10 437.37 11.62 17.77 2.59CT6 2.29 32.23 22.69 22.36 2.78 5.24 559.42 14.31 271.51 5.43 0.07 499.09 11.76 16.56 2.55CT7 5.96 29.10 30.19 20.51 2.88 4.41 581.13 12.94 266.78 5.75 0.06 390.54 10.52 16.33 2.43CT8 9.21 22.50 760.88 18.67 3.60 55.59 759.30 11.08 97.39 7.59 0.43 495.30 16.02 25.54 3.28CT9 2.20 44.52 327.73 24.78 3.30 5.57 572.74 14.36 395.34 7.97 0.10 447.58 13.21 22.20 3.05CT10 2.31 33.69 21.12 27.38 2.78 4.25 686.23 12.04 229.62 5.30 0.07 468.65 11.86 18.01 2.58CT11 4.83 36.73 313.73 26.35 2.88 4.47 750.53 14.77 331.04 6.42 0.06 496.32 11.07 16.64 2.50CT12 3.85 30.44 21.94 29.51 2.81 4.09 732.10 13.39 225.07 5.11 0.06 462.18 10.98 15.20 2.44CT13 7.57 40.18 0.00 30.46 3.57 4.68 595.24 15.15 316.65 7.02 0.08 460.52 12.26 18.92 2.79CT14 6.33 38.21 114.16 25.93 3.25 5.39 592.36 16.06 439.92 8.05 0.07 402.41 12.77 19.55 2.81CT15 9.96 28.97 62.40 18.88 2.97 4.10 564.95 15.46 497.55 8.79 0.06 176.57 12.35 20.07 2.86CT16 3.56 33.54 20.08 24.80 2.68 4.11 676.48 13.20 294.12 5.77 0.06 506.57 11.21 17.22 2.50CT17 2.42 27.43 16.66 22.01 2.73 3.78 609.76 11.32 201.36 4.73 0.09 418.16 10.19 15.49 2.33CT18 2.59 34.91 23.16 23.57 2.79 4.43 712.22 13.76 309.41 6.28 0.12 553.40 12.07 18.72 2.73CT19 3.81 32.31 28.38 22.64 2.77 6.04 498.74 13.88 288.00 5.65 0.07 463.71 11.55 17.09 2.53CT20 10.90 8.58 12.30 5.88 2.63 9.27 498.50 8.39 40.37 1.41 0.49 256.12 7.04 12.49 1.63CT21 3.28 14.16 32.97 11.87 2.52 7.54 573.52 9.59 47.95 1.66 0.13 373.14 8.29 13.00 1.81CT22 2.25 26.76 18.85 15.61 2.41 3.67 621.35 9.81 119.73 3.63 0.07 420.77 9.06 13.96 2.05CT23 11.43 10.14 30.41 15.89 2.29 6.52 615.92 10.47 54.27 1.71 0.37 406.39 8.51 13.68 2.00CT24 2.62 26.92 56.07 21.73 3.07 5.37 587.81 12.81 242.32 5.52 0.08 476.84 11.37 17.68 2.58CT25 7.47 45.41 53.80 32.29 4.56 5.39 455.19 10.08 239.61 5.16 0.25 385.94 10.23 17.92 2.20

(ppm)

Samples Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta Pb Th U

CT1 8.83 1.74 0.47 2.00 0.27 1.61 0.35 1.05 0.14 1.09 0.14 3.36 0.24 5.60 1.66 0.79CT2 14.11 3.22 0.63 2.89 0.41 2.77 0.56 1.74 0.27 1.90 0.3 11.82 0.69 7.47 3.87 1.05CT3 11.81 2.46 0.62 2.61 0.38 2.45 0.50 1.43 0.24 1.42 0.24 7.47 0.51 5.39 2.68 1.21CT4 30.67 7.25 0.09 6.66 1.02 6.52 1.41 4.43 0.63 4.61 0.69 5.24 2.87 22.04 41.74 10.77CT5 11.02 2.00 0.60 2.26 0.34 2.28 0.49 1.25 0.18 1.23 0.22 6.13 0.51 21.80 2.51 1.08CT6 11.09 2.50 0.53 2.19 0.34 2.22 0.48 1.41 0.20 1.36 0.20 5.91 0.38 6.94 2.35 1.31CT7 10.35 2.15 0.56 1.92 0.30 2.18 0.41 1.26 0.16 1.28 0.20 5.48 0.42 5.60 2.32 0.82CT8 13.74 2.69 0.74 2.47 0.37 2.04 0.36 1.10 0.17 1.10 0.14 2.31 0.48 1.92 2.82 0.88CT9 12.92 2.63 0.63 2.61 0.38 2.65 0.49 1.63 0.24 1.64 0.29 9.35 0.54 34.5 3.48 1.29CT10 11.19 2.21 0.55 2.25 0.30 2.13 0.46 1.26 0.22 1.30 0.22 5.60 0.39 186.5 2.40 1.24CT11 10.66 2.25 0.52 2.33 0.34 2.15 0.47 1.28 0.19 1.43 0.22 6.58 0.44 4.83 2.60 1.18CT12 10.28 2.23 0.58 2.29 0.32 2.04 0.42 1.26 0.20 1.15 0.19 5.08 0.35 174.7 2.15 1.06CT13 12.01 2.26 0.63 2.30 0.34 2.47 0.51 1.42 0.20 1.43 0.23 6.63 0.49 4.84 2.70 1.07CT14 12.67 2.65 0.60 2.59 0.38 2.42 0.51 1.58 0.22 1.60 0.26 9.62 0.59 31.35 3.38 1.10CT15 12.41 2.51 0.54 2.54 0.36 2.38 0.47 1.45 0.21 1.65 0.26 10.37 0.60 5.58 3.56 1.02CT16 11.00 2.26 0.53 2.25 0.34 2.20 0.48 1.35 0.23 1.36 0.24 7.06 0.46 4.94 2.60 1.16CT17 9.88 2.21 0.46 1.95 0.28 1.95 0.40 1.25 0.15 1.19 0.20 4.84 0.37 27.44 2.03 0.95CT18 11.71 2.28 0.56 2.48 0.39 2.50 0.52 1.51 0.18 1.51 0.21 7.17 0.45 5.51 2.66 1.25CT19 11.39 2.29 0.55 2.43 0.32 2.37 0.51 1.46 0.20 1.52 0.22 6.87 0.43 8.34 2.60 1.35CT20 7.49 1.62 0.41 1.75 0.21 1.36 0.30 0.91 0.10 0.68 0.10 0.94 0.10 74.36 0.92 0.47CT21 7.54 1.69 0.43 1.99 0.24 1.55 0.32 0.99 0.15 0.92 0.13 1.19 0.15 11.06 1.06 0.54CT22 8.64 1.84 0.43 1.78 0.27 1.76 0.31 0.97 0.14 0.86 0.13 2.98 0.24 5.42 1.72 1.13CT23 8.63 1.67 0.53 2.01 0.31 1.80 0.40 0.99 0.18 1.02 0.13 1.30 0.19 8.25 1.14 0.62CT24 7.13 2.47 0.57 2.27 0.32 2.20 0.46 1.35 0.19 1.39 0.20 5.51 0.42 20.84 2.24 1.46CT25 9.53 2.05 0.54 1.77 0.30 1.76 0.37 1.03 0.15 0.99 0.16 5.59 0.31 6.56 2.11 1.30

6 M. D. Bella et al. PrePub Article

eschweizerbart_xxx

raw material composition, and, eventually, provenancein terms of accessory and heavy mineral phases (Brems& Degryse, 2014).

Figures 4a–c indicate a relative enrichment in HREEwith respect to LREE. As reported by Wedepohl et al.(2011) for natron-based glass, this trend suggests the pre-sence of some peculiar heavy mineral phases in the sandyraw materials. The average REE pattern of our samples

(Fig. 5) appears distinctively more enriched than thosereported for similar soda–lime glasses by Wedepohl et al.(1997, 2011) and by Gaitzsch et al. (2000). In quartz-richsands, these elements are mostly concentrated in the clayand silt fractions, but also in accessory and heavy mineralphases (Brems & Degryse, 2014). In particular, the lightREE tend to accumulate in monazite and allanite, whereasthe heavy REE are relatively concentrated in zircon, garnetand pyroxene (Gromet & Silver, 1983; McLennan, 1989;Brems & Degryse, 2014). Figure 4 also shows slightlynegative Eu anomalies.

Table 2 shows very high levels of Sr, relatively high ofBa and very low of Rb for all the Catania glass finds.Strontium occurs in the Earth’s crust dispersed in rock-forming and accessory minerals, and can be provided byboth sand (mostly by feldspar and mica) and the limesource. Lime can be obtained from fresh beach shells(high Sr values) or from limestone (in general character-ized by relatively lower Sr values and Sr/Ca ratios)(Wedepohl & Baumann, 2000; Freestone et al., 2003;Wedepohl et al., 2011; Brems et al., 2013). Barium andRb are commonly related to alkali feldspars. The lowamount of Rb can be related to depletion in K-feldsparcontent. Concerning barium, however, the high contentspresent in our samples could be ascribed to the use ofpsilomelane-type minerals [(Ba, H2O)2 Mn5O10] as asource of manganese (e.g. Foster & Kaczmarczyk, 1982;Shortland et al., 2007; Silvestri, 2008; Arletti et al., 2010;

Fig. 4. Patterns of REE (Fig. 4a–c) and incompatible trace elements (Fig. 4d–f) of the studied HIMT and Levantine I glass samples (see thelegend for the adopted symbols). The values are normalized to upper continental crust (Wedepohl, 1995).

Fig. 5. Patterns of the normalized REE mean values of the glasssamples from Catania Amphitheatre (solid circles) and the natron-based glass samples studied by Wedepohl et al. (1997, 2011) and byGaitzsch et al. (2000) (open squares).

PrePub Article Proto-Byzantine glass workshop from Catania Roman amphitheatre 7

eschweizerbart_xxx

Guilherme et al. 2011, 2012). It should be noted that largedeposits of this mineral are located in the western side ofthe Sinai Peninsula, about 20 km inland, to the east of theSuez Gulf and in proximity to the Abou Zenima Port. Inaddition to Ba, the Mn source may also introduce extra Srto the glass (Ganio et al., 2012).

The behaviour of HFSE is particularly interesting.Sabatino (2007) and Arletti et al. (2010) already observedsignificant differences in the HFSE contents depending onthe glass types. The spider diagram in Fig. 6a shows thatthe HIMT1 and HIMT2 groups are characterized by a

peculiar relative enrichment in all the HFSE elementsrelative to the Levantine I samples. A similar behaviouris evident also in Fig. 6b and c, which report the spiderdiagrams relative to the samples studied by Arletti et al.(2010) and Conte et al. (2014). Hence, inspection ofFig. 6a–c indicates that HSFE distribution is a powerfulparameter for distinguishing between HIMT and LevantineI glass materials.

The higher HFSE contents exhibited by HIMT glassagain suggest the use of a raw material particularlyenriched in heavy minerals or in mafic mineral phases,both typical carriers of HFSE. The occurrence of correla-tions between pairs of trace elements can in principle helpin identifying which mineral phases were contained in theraw materials used for the production of the glass. To thisaim, the HFSE matrix plots with the correlation index r2

were exploited (Fig. S1, freely available online asSupplementary Material, linked to this article on theGSW website of the journal: http://eurjmin.geoscience-world.org/). The r2 value of 0.99 calculated for the Hf vs.Zr plot suggests the presence of the mineral phase zircon,whereas the correlations found for Ta vs. Ti, and Nb vs. Ti(with r2 values of 0.92 and 0.93, respectively) could implycontributions from Ti-rich heavy minerals such as ilme-nite, rutile, and titanite (Rollinson, 1995). Contributionsfrom other minerals, such as pyroxenes, garnets, amphi-boles, and magnetite, are also possible, as suggested by thepreviously discussed enrichments in the HREE. Since theelement distribution in the mineral phases depends on thecomposition of the parental rocks (Rollinson, 1995), wesuggest that the raw materials used to produce both HIMTand Levantine I glasses were representative of a maturesand, enriched in Si-rich phases, characterized by variablecontents of heavy and mafic minerals, lower for LevantineI and higher for HIMT glasses.

Freestone et al. (2000, 2002a, b, 2003) and Freestone(2006) also demonstrated that differences in the trace-ele-ment concentrations of archaeological glass can beascribed to the geochemistry of different productionareas. Specifically, ancient glass produced usingMediterranean coastal sand typically shows high Sr con-tents, due to the presence of relatively Sr-rich shells inbeach sands. Glass made using inland sand, on the otherhand, contains calcium carbonate derived from limestone,and hence is typically characterized by lower Sr contentsand Sr/Ca ratios (Wedepohl & Baumann, 2000; Freestoneet al., 2003; Wedepohl et al., 2011; Brems et al., 2013). Inthe studied HIMT and Levantine I samples, high Sr con-tents are found (Table 2; Fig. 4), which may point to thepresence of shell fragments in the rawmaterials and the useof a coastal sand. Hence, the overall chemical informationobtained from the Catania samples is indicative of a sandcontaining significant amounts of lime, derived from shellsalready present in the sand or deliberately added.

Moreover, these data suggest that the raw sand used forHIMT glass (high HFSE and HREE contents) was mostprobably derived from an area near the Nile Delta. In fact,several studies (see Frihy & Komar, 1993; Frihy et al.1995; Frihy & Dewidar, 2003) on sediment movements

Fig. 6. HFSE patterns of HIMT and Levantine I samples fromCatania Amphitheatre (a); Arletti et al. (2010) (b); Conte et al.(2014) (c). The values are normalized to upper continental crust(Wedepohl, 1995).

8 M. D. Bella et al. PrePub Article

eschweizerbart_xxx

along the Nile Delta coastline revealed a concentration ofdense opaque minerals (pyroxene, amphibole, magnetite,hematite, rutile, monazite, ilmenite, garnet, zircon andtourmaline) within the erosional areas of the Nile Delta,due to the selective transport of the different phases. Theseheavy minerals come from magmatic and metamorphicrocks of the northern Arabian-Nubian massif (Kroneret al., 1990; El-Metwally et al., 1996; Stein & Goldstein,1996; Cavazza et al., 2004). On the contrary, the LevantineI glass is probablymade with sands from areas more distantfrom the Nile Delta, located to the East (Israel), where thecontribution of the heavy mineral phases is lower. It hasbeen demonstrated that light minerals, such as quartz andfeldspar, move faster than the heavy ones along the NileDelta coastline, carried by the dominant northwest waves,generated along the length of the Mediterranean Sea(Nafaa et al., 1991; Frihy & Komar, 1993; Frihy et al.,1995; Frihy & Dewidar, 2003).

The natural obsidian sample (CT4) deserves some com-ments. To determine its provenance, its trace-elementcomposition was compared to those of a number of obsi-dian samples from various geological sources, analyzed byBarca et al. (2007, 2008) with LA-ICP-MS method. Theseauthors discuss the differences among four geologicalsources of the peri-Thyrrenian area, distinguishing sevencompositional groups. Three of these are attributed toLipari, Palmarola and Pantelleria islands. The other fourgroups belong to the Monte Arci complex in Sardinia(labelled SA, SB1, SB2 and SC in Barca et al., 2007).The La vs. Zr/Y classification diagram (Fig. 7) indicatesthat sample CT4 probably came from Lipari Island(Aeolian volcanic arc).

4. Conclusions

Analysis of major, minor and trace elements present in thetwenty-five glass samples from a Proto-Byzantine

glassware of the Catania Roman Amphitheatre allows foridentification of two main groups of natron-based silica–-lime glasses and one sample of obsidian. Most samples areHIMT glass, whereas three are Levantine I glass. AmongHIMT samples, 18 show HIMT1 signature, and only twofragments belong to the HIMT2 sub-group. The presenceof both HIMT and Levantine I compositions among ourglass fragments confirms that both glass types were used atthe same time to produce similar objects.

The HIMT group shows enrichments in a number oftrace elements with a geochemical signature whichwould suggest the use of a raw sand containing heavymineral phases, whereas Levantine I samples aredepleted in these elements. The high Sr contents indi-cate significant amounts of lime in the raw sand, prob-ably derived from fresh beach shells already present inthe sand or intentionally added. The noticeable differ-ences in all the HFSE contents exhibited by theenriched HIMT and the depleted Levantine I samplesallow us to propose these elements as geochemicaldiscriminating factors between the two categories.This assumption is also confirmed by the analysis ofliterature data relative to coeval similar glass types.

Acknowledgements: This project was partially financiallysupported by the University of Messina. The authors thankSimona Bigi (EMPA Laboratory of the University ofModena and Reggio Emilia) for the technical support dur-ing the chemical analyses. Two anonymous reviewers andthe Editor Reto Giere greatly improved the manuscriptwith their comments and suggestions.

References

Aerts, A., Velde, B., Janssens, K., Dijkman, W. (2003): Change in

silica sources in Roman and post-Roman glass. Spectrochim.

Acta B, 58, 659–667.

Arletti, R., Giacobbe, C., Quartieri, S., Sabatino, G., Tigano, G.,

Triscari, M., Vezzalini, G. (2010): Archaeometrical investiga-

tion of Sicilian early Byzantine glass: chemical and spectro-

scopic data. Archaeometry, 52, 99–114.

Arletti, R., Giordani, N., Tarpini, R., Vezzalini, G. (2005):

Archaeometrical analyses of glass from western Emilia

Romagna (Italy) from the Imperial Age. In: annales du 16

Congres de l’ Association Internationale pour l’Histoire du

Verre, 80–84, Notthingham.

Barca, D., De Francesco, A.M., Crisci, G.M. (2007): Application of

Laser Ablation ICP-MS for characterization of obsidian frag-

ments from peri-Tyrrhenian area. J. Cult. Herit., 8, 141–150.

Barca, D., De Francesco, A.M., Crisci, G.M., Tozzi, C. (2008):

Provenance of obsidian artifacts from site of Colle Cera,

Italy, by LA-ICP-MS method. Period. Mineral., 77, 41–52.

Beste, H.J., Becker, F., Spigo, U. (2007): Studio e rilievo sull’anfi-

teatro romano di Catania. Bollettino dell’Istituto archeologico

germanico, sezione romana, 113, 595–613.

Fig. 7. La vs. Zr/Y obsidian classification diagram from Barca et al.(2007). It reports sample CT4 (black dot) and the areas of composi-tional groups of obsidian samples from Lipari, Palmarola, Pantelleriaand four obsidian subgroups (SA, SB1, SB2, SC) from Monte Arci(Sardinia) (Barca et al. 2007).

PrePub Article Proto-Byzantine glass workshop from Catania Roman amphitheatre 9

eschweizerbart_xxx

Brems, D. & Degryse, P. (2014): Trace element analysis in provenan-

cing Roman glass-making. Archaeometry, 56(SI Supplement 1),

116–136.

Brems, D., Ganio, M., Latruwe, K., Balcaen, L., Carremans, M.,

Gimeno, D., Silvestri, A., Vanhaecke, F., Muchez, P., Degryse,

P. (2013): Isotopes on the beach Part 1 – strontium isotope ratios

as a provenance indicator for lime raw materials used in Roman

glassmaking. Archaeometry, 55, 214–234.

Cavazza, W., Roure, F., Ziegler, P. (2004): The mediterranean area

and the surrounding regions: active processes, remnants of for-

mer tethyan oceans and related thrust belts. in ‘‘The

TRANSMED Atlas’’, W. Cavazza, F. Roure, W. Spakman,

G.M. Stampfli and P Ziegler, eds., Springer-Verlag Berlin,

Heidelberg, New York, 1–29.

Conte, S., Chinni, T., Arletti, R., Vandini, M. (2014): Butrint

(Albania) between eastern and western Mediterranean glass

production: EMPA and LA-ICP-MS of late antique and early

medieval finds. J. Archaeol. Sci., 49, 6–20.

Degryse, P. & Schneider, J. (2008): Pliny the Elder and Sr Nd

isotopes: tracing the provenance of raw materials for Roman

glass production. J. Archaeol. Sci., 35, 1993–2000.

Degryse, P., Schneider, J., Lauwers, V., Henderson, J., Van Daele,

B., Martens, M., Huisman, H.D.J., De Muynck, D., Muchez, P.

(2009): Neodymium and strontium isotopes in the provenance

determinations of primary glass production. in ‘‘Isotopes in

vitreous materials, studies in archaeological sciences 1’’,

Degryse et al., eds. Leuven University Press, Leuven, 53–72.

Donovan, J.J. & Rivers, M.L. (1990): PRSUPR – a PC based auto-

mation and analysis software package for wavelengh dispersive

electron-beam microanalysis. in ‘‘Microbeam analysis’’,

J.R. Michael, P. Ingram, eds., Proc. Micro-Beam Analysis

Society, San Francisco, 66–68.

El-Metwally, A.A., Ibrahim, M.E., Ali, M.M. (1996): Pan African

high grade metamorphites from the Gabal Magafa, Sinai, Egypt:

mineralogical and geochemical constraints. Mansoura Univ,

Fac. Sci. Sci. J., 23, 17–42.

Foster, H. & Jackson, C.M. (2009): The composition of naturally

coloured late Roman Vessel glass from Britain and the implica-

tions for models of glass production and supply. J. Archeol. Sci.,

36, 189–204.

Foster, K.P. &Kaczmarczyk, A. (1982): X-ray fluorescence analysis

of some Minoan Faience. Archaeometry, 24, 143–157.

Foy, D.M., Vichy, M., Picon, M. (2000): Lingots de verre en

Mediterranee occidentale. Annales 14th Congres de l’Association

pour l’Histoire du verre, AIHV, Amsterdam, 51–57.

Foy, D., Picon, M., Vichy, M., Thirion-Merle, V. (2003):

Caracterisation des verres de la fin de l’antiquite en

Mediterranee occidentale: l’emergence de nouveaux courants

commerciaux. in ‘‘Echanges et commerce du verre dans le

Monde Antique’’, D. Foy. M.D. Nenna, eds. Editions Monique

Mergoil, Montagnac, 41–85.

Freestone, I.C. (1994): Chemical analysis of ‘‘raw’’ glass fragments.

in ‘‘Excavation of Carthage. Vol II, the circular harbour, north

side’’, H.R. Hurst, ed. Oxford University Press, Oxford, 290 p.

— (2003): Primary glass sources in the mid-first millennium AD.

Annales du 15eme Congres de l’Association Internationale pour

l’Histoire du Verre. New York-Corning, 111–115.

— (2006): Glass production in Late Antiquity and the Early Islamic

period: a geochemical perspective. in ‘‘Geomaterials in cultural

heritage’’, M. Maggetti & B. Messiga, eds. Geological Society

of London, Special Publication 257, London, 201–216.

Freestone, I.C., Gorin-Rosen, Y., Huges, M.J. (2000): Primary glass

from Israel and the production of glass in late antiquity and early

Islamic period. in ‘‘La route du verre: Ateliers primaires et

secondaires du second millenaire av. J.-C. au Moyen Age’’,

M.D. Nenna, ed. Travaux de la Maison d’Orient mediterraneen,

Lyon, 33, 65–83.

Freestone, I.C., Greenwood, R., Gorin-Rosen, Y. (2002a): Byzantine

and Early Islamic glassmaking in the eastern Mediterranean:

production and distribution of primary glass, in Hyalos

¼vitrum¼glass: history, technology and conservation of glass

and vitreous materials in the Hellenic world, proceedings of the

first international conference, Rhodes, Greece, 1–4 April

2001(ed. G. Kordas), 167–74, Glasnet Publications, Athens.

Freestone, I. C., Ponting, M., Hughes, J. (2002b): Origins of

Byzantine glass from Maroni Petrera, Cyprus. Archaeometry,

44, 257–272.

Freestone, I. C., Leslie, K. A., Thirlwall, M., Gorin-Rosen, Y.

(2003): Strontium isotopes in the investigation of early glass

production: Byzantine and early Islamic glass from the Near

East. Archaeometry, 45, 19–32.

Freestone, I. C., Wolf, S., Thirlwall, M. (2005): The production of

HIMT glass: elemental and isotopic evidence. In Annales du 16e

Congres de l’Association Internationale pour l’Histoire du

Verre, London, 153–7, AIHV, Nottingham.

Frihy, O.E. &Dewidar, K.M. (2003): Concentration and grain size to

interpret boundaries of littoral sub-cells of the Nile Delta, Egypt.

Mar. Geol., 199, 27–43.

Frihy, O.E. & Komar, P.D. (1993): Long-term shoreline changes and

the concentration of heavy minerals in beach sands of the Nile

Delta, Egypt. Mar. Geol., 115, 253–261.

Frihy, O.E., Lotfy, M.F., Komar, P.D. (1995): Spatial variations in

heavy minerals and patterns of sediment sorting along the Nile

Delta, Egypt. Sediment. Geol., 97, 33–41.

Gaitzsch, W., Follmann-Schulz, A.B., Wedepohl, K.H., Hartmann,

G., Tegtmeier, U. (2000): Spatromische Glashutten im

Hambacher Forst – Produktionsort der ECVA-Fasskruge.

Bonner Jahrbucher, 200, 81–240.

Ganio, M., Boyen, S., Fenn, T., Scott, R., Vanhoutte, S., Gimeno, D.,

Degryse, P. (2012): Roman glass across the empire: an elemental

and isotopic characterization. J. Anal. Atom. Spectrom., 27, 743–753.

Giordano, F. (2002): L’Anfiteatro romano di Catania. Boemi

Editore, Catania, 2002.

Gromet, L. P. & Silver, L. T. (1983): Rare earth element

distributions among minerals in a granodiorite and their

petrogenetic implications. Geochim. Cosmochim. Acta, 47,

925–939.

Guilherme, A., Buzanich, G., Radtke, M., Reinholz, U., Coroado, J.,

Dos Santose, J.M.F. (2012): Synchrotron micro-XRF with

Compound Refractive Lenses (CRLs) for tracing key elements

on Portuguese glazed ceramics. J. Anal. Atom. Spectrom., 27,

966–974.

Guilherme, A., Coroado, J., Dos Santos, J.M.F., Luhl, L., Wolff, T.,

Kanngießer, B., Carvalho, M.L. (2011): X-ray fluorescence

(conventional and 3D) and scanning electron microscopy for

the investigation of Portuguese polychrome glazed ceramics:

advances in the knowledge of the manufacturing techniques.

Spectrochim. Acta B, 66, 297–307.

Henderson, J. (1985): The raw materials of early glass production.

Oxford J. Archaeol., 4, 267–291.

— (2013): Ancient Glass: An Interdisciplinary Exploration.

Cambridge University Press, New York, 450 p.

10 M. D. Bella et al. PrePub Article

eschweizerbart_xxx

Kroner, A., Eyal, M., Eyal, Y. (1990): Early Pan-African evolution

of the basement around Elat, Israel, and the Sinai Peninsula

revealed by single-zircon evaporation dating, and implications

for crustal accretion rates. Geology, 18, 545–548.

Isings, C. (1957): Roman glass: from dated finds. Archaeologica

Traiectina, J.B. Wolters, Groningen, 78–81.

Leocata, P. (1999): Riapre l’anfiteatro romano. Articolo su ‘‘La

Sicilia’’, 10 luglio 1999, CT31.

Leslie, K.A., Freestone, I.C., Lowry, D., Thirlwall, M. (2006):

Provenance and technology of near Eastern glass: oxygen iso-

topes by laser fluorination as a compliment to Sr. Archaeometry,

48, 253–270.

Longerich, H.P., Jackson, S.E., Gunther, D. (1996): Laser ablation

inductively coupled plasma mass spectrometry transient signal

data acquisition and analyte concentration calculation. J. Anal.

Atom. Spectrom., 11, 899–904.

McKay, G.A. (1989): Partitioning of rare earth elements between

major silicate minerals and basaltic melts. in ‘‘Geochemistry and

mineralogy of rare earth elements’’, B.R. Lipin & G.A. McKay,

eds. Rev. Mineral., 21, Mineralogical Society of America,

Chantilly, VA, 45–77.

McLennan, S. M. (1989): Rare earth elements in sedimentary rocks:

influence of provenance and sedimentary processes. in

‘‘Geochemistry and mineralogy of rare earth elements’’, B. R.

Lipin and G. A. McKay, eds. Rev. Mineral., 21, Mineralogical

Society of America, Chantilly, VA, 169–200.

Mirti, P., Casoli, A., Appolonia, L. (1993): Scientific analysis of Roman

glass from Augusta Praetoria. Archaeometry, 35, 225–240.

Nafaa, M.G., Fanos, A.M., Elganainy, M.A. (1991): Characteristics

of waves off the Mediterranean coast of Egypt. J. Coast. Res., 7,

665–676.

Nikita, K. & Henderson, J. (2006): Glass analyses from Mycenaean

Thebes and Elateia: compositional evidence for a Mycenaean

glass industry. J. Glass Stud., 48, 71–120.

Petrelli, M., Perugini, D., Alagna, K.E., Poli, G., Peccerillo, A.

(2008): Spatially resolved and bulk trace element analysis by

laser ablation–inductively coupled plasma–mass spectrometry

(LA–ICP–MS). Period. Mineral., 77, 3–21.

Rollinson, H.R. (1995): Using geochemical data: evaluation, pre-

sentation, interpretation, Longman Geochemistry Series.

Longman, Essex, 352 p.

Sabatino, G. (2007): Vetri archeologici di eta romana (dal II sec. a.C.

al VI sec. d.C.) in Sicilia: attribuzione di provenienza e

caratterizzazione delle tecniche costruttive. PhD thesis,

Messina, February 16, 2007.

Sanderson, D.C.W., Hunter, J.R., Warren, S.E. (1984): Energy dis-

persive X-ray Fluorescence analysis of 1st Millennium AD glass

from Britain. J. Archaeol. Sci., 11, 53–69.

Schibille, N., Marii, F., Rehren, Th. (2008): Characterization and

provenance of Late Antique windows glass from Petra Church in

Jordan. Archaeometry, 50, 627–642.

Shortland, A.J., Rogers, N., Eremin, K. (2007): Trace element dis-

criminants between Egyptian and Mesopotamian late Bronze

Age glasses. J. Archaeol. Sci., 34, 781–789.

Silvestri, A. (2008): The coloured glass of Iulia Felix. J. Archaeol.

Sci., 35, 1489–1501.

Sposito, C. (2003): L’Anfiteatro Romano di Catania:

Conoscenza-Recupero- Valorizzazione. Flaccovio Editore,

Palermo.

Stein, M. & Goldstein, S.L. (1996): From plume head to continental

lithosphere in the Arabian-Nubian shield.Nature, 383, 773–778.

Wedepohl, K.H. (1995): The composition of the continental crust.

Geochim. Cosmochim. Acta, 59, 1217–1232.

Wedepohl, K.H. & Baumann, A. (2000): The use of marine mollus-

kan shells for Roman glass and local raw glass production in the

Eifel area (Western Germany). Naturwissenschaften, 87,

129–132.

Wedepohl, K.H., Winkelmann, W., Hartmann, G. (1997): Glasfunde

aus der karolingischen Pfalz in Paderborn und die fruhe

Holzasche-Glasherstellung. Ausgrabungen und Funde in

Westfalen Lippe, 9A, 41–53.

Wedepohl, K.H., Simon, K., Kronz, A. (2011): Data on 61 chemical

elements for the characterization of three major glass composi-

tions in late antiquity and the Middle Ages. Archaeometry, 53,

81–102.

Verita, M. (1995): Le analisi del vetri. in ‘‘Le Verre de l’Antiquite

Tardive et du Haut Moyen Age’’, D. Foy, ed. Musee

Archeologique Departemental du Val d’Oise, 291–300.

Young, E., Myers, A., Munson, E., Conklin, N. (1969): Mineralogy

and geochemistry of fluorapatite from Cerro de Mercado,

Durango, Mexico. U.S. Geological Survey, Professional Paper,

650-D, 84–93.

Received 22 July 2014

Modified version received 03 March 2015

Accepted 03 March 2015

PrePub Article Proto-Byzantine glass workshop from Catania Roman amphitheatre 11