- Email: [email protected]
An archaeometric study of the Phoenician ceramics found at the São Jorge Castle's hill in Lisbon
Ceramics International xxx (xxxx) xxx–xxx
Contents lists available at ScienceDirect
Ceramics International journal homepage: www.elsevier.com/locate/ceramint
An archaeometric study of the Phoenician ceramics found at the São Jorge Castle's hill in Lisbon L.F. Vieira Ferreiraa,∗, E. de Sousab, M.F.C. Pereirac, S. Guerrab, I. Ferreira Machadoa,d a
CQFM-Centro de Química-Física Molecular, IN-Institute for Nanosciences and Nanotechnologies, IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal b UNIARQ - Centro de Arqueologia da Universidade de Lisboa, Departamento de História, Faculdade de Letras - Universidade de Lisboa, Portugal c CERENA - Centro de Estudos em Recursos Naturais e Ambiente, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal d Polytechnic Institute of Portalegre, P-7300-110, Portalegre, Portugal
A R T I C LE I N FO
A B S T R A C T
Keywords: Phoenician ceramics Western-Phoenician colonies Lisbon-Phoenician ceramics Lisbon's Castle hill Clay materials
A detailed archaeometric study of Phoenician ceramics found in an excavation inside the medieval walls of São Jorge's Castle in Lisbon is described here. Thirty ceramic sherds were studied, grouped into six categories, namely amphorae, containers for domestic use, red slip wares, grey wares, cooking wares and also some indigenous tradition handmade wares. Micro-Raman, X-Ray Fluorescence Emission, X-Ray Diffraction and ground state diffuse reflectance absorption measurements were correlated and used as our main analytical techniques to perform this study. At least three totally different local clay sources were used to produce the here studied pottery, one of alluvial origin using clays collected along the river banks, and another one using clays probably extracted in the oriental part of the Castle's hill. Cooking-ware was made with the use of raw materials with sandy detrital origin. Evidence was also found showing that part of the amphorae, common containers, and grey wares were made with the same raw materials as used in the Phoenician kilns of Almaraz, located in the left margin of the Tagus River, roughly facing Lisbon's Castle hill. The temperatures of the kilns used to fire the amphorae and common containers was in most cases higher than the one used for firing red slip and grey tableware. A detailed laboratorial study of the alluvial clays fired at different temperatures and collected in the Tagus River banks, allowed us, in most cases, to establish the origin of the sources used to produce the Phoenician pottery found in Lisbon.
1. Introduction Following a recent study of the amphorae produced at the Phoenician archaeological site of Almaraz [1], located in the old part of the city of Almada, South shore of the Tagus River [2], a new archaeometric study was developed for the Phoenician ceramics found in the area of São Jorge Castle located in Lisbon, at the top of a hill in the right margin, facing the river. The Tagus Estuary occupation by Phoenician settlers started by the end of the 9th century beginnings of the 8th century B.C., based in radiocarbon dating's [3], although the artefacts recovered so far point to a latter chronology, between the late 8th/early 7th century B.C. A good description of the main orientalising settling places in the Tagus Estuary can be found in Ref. [4]. Recently, an important archaeological finding was made, a stele with Phoenician inscriptions, dated from the 7th century B.C [5]. This ∗
excavation was made not far from the local where the ceramics of this study were collected, and both are located in the South side of the Castle's hill. This stele, the oldest Phoenician epigraphic lapidary found in the Iberian Peninsula, is a proof of the importance of this settlement. The surface decoration of the Phoenician ceramics found in the Lisbon's Castle hill are quite similar to other Iron Age Phoenician settlements located in the Mediterranean, with monochromatic (red decorated) and dichromatic (black and red decorated) styles, the majority of which are geometrical [6]. In this study a detailed spectroscopic characterization of the surfaces and ceramic bodies of 30 Phoenician ceramic sherds from the Castle's hill in Lisbon is presented, and the correlation with the data obtained for clays from western and oriental geological formations in Lisbon, allowed to discuss the provenance of the raw materials used to produce the Lisbon Phoenician ceramics. The data presented in this study are also extremely significant considering that for the first time
Corresponding author. E-mail address: [email protected] (L.F. Vieira Ferreira).
https://doi.org/10.1016/j.ceramint.2019.11.267 Received 17 November 2019; Received in revised form 27 November 2019; Accepted 28 November 2019 0272-8842/ © 2019 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Please cite this article as: L.F. Vieira Ferreira, et al., Ceramics International, https://doi.org/10.1016/j.ceramint.2019.11.267
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 1. Phoenician ceramics recovered from the Tagus River estuary: some examples of red slip and grey tableware as well as an amphorae or containers. (from the Millennium BCP exhibition in Lisbon, 2014 - “Lisboa pré-clássica: um porto mediterrâneo no litoral atlântico”). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)
The Iron Age occupation of São Jorge's Hill is, without any doubt, one of the most important in the Portuguese territory. Several studies estimate that the main parts of this settlement were located in the hilltop and southern slope, extending over an area of about 11 ha [8] during the late 8th – 6th century B.C. Although its population entailed, originally, both foreign Western-Phoenician settlers and local communities, the archaeological evidences support that it was the Phoenician cultural matrix the one that prevailed during the first half of the 1st millennium B.C., as we can see by the overwhelming majority of wheelmade ceramic productions of Phoenician tradition, the presence of architectural elements such as orthogonal construction plans using adobe bricks or “taipa” for lifting the walls [11], and the presence of inscriptions in Phoenician language and writing, among which the extraordinary funerary stele previously referred [5]. The compiled data seems to suggest that the habitat located in São Jorge's Hill may have actually been a Phoenician colony during the Iron Age earliest stages [11,12]. The study collected five sherds of each of the ceramic categories retrieved in primary layers dating from the 7th and 6th centuries B.C. from Largo de Santa Cruz: amphorae, common ware (containers), red slip ware, grey ware, cooking ware and handmade wares.
these analytical approaches were applied to the entire ceramic categories used during the early Iron Age in Western Iberia, enabling therefore a comparison of different techniques used in the production kilns. Some representative examples of Phoenician ceramics found in Lisbon are shown in Fig. 1. 2. Archaeological context and framework Archaeological discoveries carried out during the last decade have enlightened the importance of the Phoenician presence in the Tagus area, particularly in Lisbon, during the early 1st millennium B.C. Even though this presence had already been noticed and valued since the late 20th century [7], the absence of detailed stratigraphic sequences concerning the first moments of human occupation at São Jorge's Hill, in Lisbon, hampered a more substantial reading of the impact that the arrival of these settlers had on the indigenous communities which previously inhabited the area. Thanks to recent urban archaeological interventions, these shortcomings have been progressively exceeded. For the purpose of this paper we should highlight recent excavations carried out in the hilltop of São Jorge's Hill, in Largo de Santa Cruz do Castelo, which brought to light a series of preserved archaeological contexts dated from the 7th to the 5th centuries B.C [8]. The importance of these findings lies in the fact that it enabled one to characterize the local material culture assemblages, which are undeniably related with the Phoenician cultural matrix. The foreign community that settled in São Jorge's Hill during the late 8th/early 7th centuries B.C. was probably originated from the Phoenician settlements in Southern Andalusia, some of which were founded at least 150 years earlier. The constant interactions with local communities during this time naturally brought important cultural changes to both sides. A classic example of this phenomenon is known as the Phoenician “grey wares”, practically unique in the Iberian Peninsula, but unknown in other Phoenician settlements in Central and Eastern Mediterranean, which were the result of a symbiotic interaction that gathered both Phoenician production techniques and local Iberian aesthetic traditions [9]. Common features can be observed in the fine wares (red slip ware and grey ware), containers and transport vessels (Cruz del Negro type urns, pithoi and amphorae) and in the cookingwares, even if the morphological shapes and decorations may vary [10]. Nonetheless, the complex process of the Orientalisation of the Portuguese coast also involves other agents, namely the indigenous communities that previously resided in the area. The presence of these individuals is testified through handmade wares, which follow the previous local Late Bronze Age traditions, and that are an important part of the early Iron Age pottery assemblages found in São Jorge's Hill, even if its representativeness is progressively reduced over the centuries [8,11].
3. Geological setting The Lisbon region presents two different geological areas: the first one is located North of Tagus River, where one can find Cretaceous, Paleogenic (basalt complex of Lisbon) and Neogenic (Miocene) formations [13]. South of Tagus River also some Miocenic outcrops can also be found, namely Almada, Trafaria and Costa da Caparica. A second region South of Tagus River should also be mentioned, quite different from the first one, and corresponds to Pliocene areas [13,14]. Several lithologies, including Cretaceous and Paleogenic rocks exposed in Lisbon district are known as good sources of raw materials (ornamental and building stones, aggregates, ceramic, glass …) from pre-historical times until nowadays (Museu de Lisboa, 2017). “Prazeres Clays” formation—Aquitanian to Lower Burdigalian; “Brick Oven Clays” formation—Burdigalian; “Xabregas Blue Clays” formation—Upper Langhian and Serravallian) constitute very important deposits [15,16] traditionally grouped as west Lisbon and east Lisbon clay sources, for white or red clays [16]. Alternative sources of historical ceramic products are modern terrace and alluvial formations in both margins of Tagus River and their tributaries [17]. Mineralogy of Miocene raw materials (claystones or marly limestones), collected at several industrial and historical reference sites, including samples from IST Geosciences Museum, is remarkably constant, although the amount of calcite and iron oxides changes from place to place. Quartz, muscovite and/or illite and kaolinite are the main constituents of the Pliocene raw materials [18,19]. 2
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
and data processing, namely the baseline correction was done when needed, with the Wire 4 software or with the LabSpec software from Jobin Yvon. Ceramics (cup and sherds) were analysed either from the surface of the cup or from ground sherd fragments (10–20 mg). Further details about the use of this spectroscopic tool can be found in Refs. [20–25]. 4.2.2. X-ray fluorescence The elemental chemical composition of ceramic pastes was also determined by X-ray fluorescence with the use of a Niton XL3T GOLDD spectrometer (Thermo Scientific) with a 50 kV/200 μA X-ray generator, 3 mm spot diameter for excitation. Further details can be found in Refs. [20–25]. 4.2.3. X-ray diffraction The identification of the ceramic body powder crystalline phases was carried out by using of a X-Ray diffractometer at CERENA (Panalytical X'PERT PRO model), with CuKα radiation. The measurement parameters used were: 2θ (5–70°); step size 2θ = 0.033° and a scan step time of 80 s with generator settings of 35 mA and 40 kV. In the case of XRD measurements only about 10 mg of powder sample are needed to perform an experiment, so it can be considered a quasi-nondestructive technique. The estimated penetration depth is about 30 μm. 4.2.4. Ground state diffuse reflectance absorption spectroscopy Ground-state absorption studies were performed using a homemade diffuse reflectance setup, as described in Refs. [20–26], with the use of three standards, barium sulfate powder and Spectralon white and grey disks.
Fig. 2. Phoenician ceramic sherds from Lisbon's castle area.
4. Materials and methods 4.1. Samples
4.3. General
30 pottery sherds were spectroscopically studied and the experimental results are grouped into six categories, as shown in Fig. 2. Sherds A1 to A5 are from amphorae, with or without a beige engobe; sherds C1 to C5 are from containers for domestic use, also with beige engobe; sherds R1 to R5 are from red slip tableware and all present a well visible red superficial coloration, some darker than others; sherds G1 to G5 are from grey tableware, dark ceramic body and even darker surface; K1 to K5 sherds are examples of cooking ware and its surface evidences black carbon deposits certainly due to the contact with the flames during food preparation. Finally samples H1 to H5 are considered to be indigenous tradition handmade wares and its ceramic body presents coarse grains. A simple visual observation of the ceramic bodies indicates that the used raw materials were extracted from different clay sources.
In what regards the firing procedure of the collected clay samples at laboratory level, all samples were placed in porcelain crucibles and submitted to a heat treatment in a high temperature chamber electric furnace (Nabertherm, Germany), in a range of 750 °C to 950 °C from 8 up to 36 h, with a heating rate of about 5 °C/min, and were allowed to return to room temperature with an identical rate. Figures presented as supplementary material were obtained with an Olympus OMD camera, using a macro lens. 5. Results and discussion 5.1. Μicro-Raman spectroscopic data Micro-Raman spectroscopy was used to characterize the surface of the sherds and also of the ceramic bodies.
4.2. Experimental techniques under use 5.1.1. Surface pigments of the Phoenician sherds The micro-Raman spectra obtained for the surface of the Phoenician sherds (beige engobe for the amphorae and common containers), red or dark red for the red slip tableware, black or dark grey for the grey tableware, dark braun or black for the cooking ware and reddish or dark braun for the handmade wares are shown in Fig. 3i)–vii), while Fig. 4i)–vii) presents data for the ceramic bodies analysed from powders removed from the sherds. Curve (i) in Fig. 3 is from the superficial engobe of the A4 sherd. All amphora sherds have a red/greyish ceramic body and are covered with a beige engobe, which in some cases was partially detached. Several peaks located at 245, 439 and 611 cm−1 show the presence of rutile (TiO2), but the peak at 146 cm−1 evidences the presence of anatase. The other peaks of anatase could not be detected because they overlap the peaks of rutile which are stronger. Most probably some anatase in the initial slip was transformed into rutile whenever the kiln temperature was enough high to perform that transformation, as we will see later in the analysis of the diffractogram patterns.
4.2.1. Micro-Raman spectrometry Micro-Raman measurements were carried out with the with use of a Renishaw InVia confocal Raman microscope, in a back-scattering micro-configuration, A powerful 300 mW, 532 nm laser excitation (Cobolt, Samba model) and 100×, 50×, 20×, 10× and 5× objectives in a Leica microscope. In most spectral collection was made with the use of a 50× long working distance objective. The spectral resolution of the Raman spectrometer was ~1 cm−1. A second excitation laser was used (λexc = 785 nm) which enabled us to identify some minerals in the ceramic body which was not achieved with the green excitation, namely calcium carbonate. The Renishaw equipment has accurate confocal capabilities, enabling in-depth studies from the surface to about 150 μm. All Raman spectra were recorded at least in 5 different spots for each sample, and all spectra presented in this paper are representative of the samples under study. Data acquisition was performed with the Renishaw software Wire 4 3
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 4. Micro-Raman spectra from the Phoenician ceramic bodies i) Amphorae A4; (ii) Container C3; (iii) Red slip ware R5; (iv) Red slip ware R5; (v) Grey ware G3; (vi) Cooking ware K1: (vii) Handmade ceramics H5. The Raman signals are assigned to: Anorthite (An), Albite (Alb), Calcite (CC), Hematite (H), Magnetite (M), Anatase (A) and Carbon Black (CB).
Fig. 3. Micro-Raman spectra from the sherds' surfaces. (i) Amphorae A4; (ii) Amphorae A2; (iii) Container C3; (iv) Red slip ware R2; (v) Grey ware G1; (vi) Cooking ware K3: (vii) Cooking ware K4. The Raman signals are assigned to: Rutile (R), Anatase (A), Albite (Alb), Carbon Black (CB), Hematite (H) and Quartz (Qz).
5.1.2. Ceramic bodies Important information regarding the firing conditions and even origins of the pottery sherds from the Phoenician ceramics from Lisbon Castle could be obtained from the micro-Raman study of the ceramic bodies. Curve (i) from Fig. 4 is from sherd A4 and clearly exhibits anorthite. Anorthite is a calcium alumino-silicate (CaAl2Si2O8) and it requires high temperatures of the kiln to be formed, about 950 °C [28–30]. The main peaks are located at 193, 279, 478, 506, 558, and 970 cm−1. Curve (ii) is from sherd C3, a container. One can clearly identify calcite (CC, peaks at 152, 715, 1080 cm−1). Also albite peaking at 152, 285, 475, 509 cm−1 could be detected as well as some carbon black at longer wavenumbers. The detection of albite shows that the firing temperature of this paste did not reach values high enough for the transformation of albite into anorthite to occur, consistent with firing temperatures well below 950 °C, even enabling the “survival” of calcite, well known to completely disappear at ~850 °C [31,32]. Curves (iii) and (iv) were obtained for sherd R5, exciting at different spots. In the case of curve (iii), hematite (H, peaking at 118, 229, 293, 408, 505 and 1333 cm−1), magnetite (M, 678 cm−1) and some carbon black could be identified. The main difference for curve (iv) is that Anatase is superimposed onto the hematite Raman peaks (A, 150, 399, 505 and 628 cm−1). The white colour of anatase certainly makes the red colour brighter. Curve (v) for the grey ware exhibits huge amounts of carbon black and small quantities of albite. Curves (vi) and (vii) from Fig. 4 also provide important information because in all cases albite is the dominant mineral in the ceramic body. The fact that this mineral exists in all these ceramic bodies shows again that the kiln's temperature was not high enough for them to be transformed into anorthite. XRD studies presented later in this paper will
Curve (ii) in Fig. 3 is from the surface of amphora A2. Although a small peak of anatase could be detected, the main Raman peaks are from albite, a sodium feldspar (Alb, peaks being located at 165, 290, 406, 476, 508, 760 and 810 cm−1), and also carbon black (CB, peaks at about 1357 and 1560 cm−1). These peaks are more representative of the ceramic body than of the engobe, which puts in evidence the cracks all over the surface. Curve (iii) in Fig. 3 is from a beige zone of the surface of container C3, and again the dominant peaks belong to rutile although a small amount of anatase can be seen at 144 cm−1. Clearly the engobe is dominated by the presence of the rutile polymorph of titanium dioxide. Curve (iv) in Fig. 3 is from a red area of the surface of R2 sherd and the peaks were detected at 121, 220, 288, 403, 460, 611, 656 and 1316 cm−1. These Raman peaks clearly identify hematite (Fe2O3) [27], here associated to the red coloration of other parts of the cup's surface and also reveal the presence of quartz (Q, 461 cm−1). Small amounts of carbon black could also be detected, and these of course are associated with the darkening of the red surface. Curve (v) of Fig. 3 refers to the black or dark/grey surface, where the presence albite and anatase is clear as well as large amounts of carbon black peaking at 1375 and 1607 cm−1. This large amount of carbon black is of course the responsible for the black coloration of the surface. In Fig. 3, curves (vi) for K3 and (vii) for K4 identify the presence of quartz (Q), with peaks at 124, 194, 355, 461 and 1169 cm−1 that clearly indicate the crystalline silica of these samples. Also anatase (A, peaks at 145, 399, 633 cm−1) could be detected in this cooking ware, as well as large Raman signatures of carbon black. 4
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 5a. Diffractograms from Phoenicians ceramics of Lisbon: two amphora A4 and A2, and two common vessels (containers) C5 and C2. The XRD peaks are assigned to: Quartz (Qz), Anorthite (An), Diopside (D), Hematite (H), M (Muscovite), Albite (Alb), Microcline (Mic), and Calcite (CC).
Fig. 5b. Diffractograms from Phoenicians ceramics of Lisbon: Curve (i) – Red slip ware R5; Curve (ii) – Grey ware G3; Curve (iii) – Cooking ware K3; Curve (iv) – Handmade ceramics H3. The XRD peaks are assigned to: M (Muscovite), Quartz (Qz), Albite (Alb), Calcite (CC), Hematite (H), Anorthite (An), Diopside (D), Gehlenite (G) and Microcline (Mic).
show us that all these ceramic bodies were formed by the use of Miocenic clays. For temperatures below or around 850 °C anorthite was not formed and the minerals existing in the initial raw material remain unchanged, as is the case of albite. Curve (v) clearly indicates the presence of black carbon in the ceramic body of the grey tableware. No specific curves regarding the spectroscopic Raman signature of quartz are presented in Fig. 4, however quartz exists in all the studied ceramic bodies.
after firing. In the case of curve (ii) of Fig. 5a, one can note the presence of muscovite (M) and also of albite, a sodium alumino-silicate. (Alb, NaAlSi3O8). These minerals exist in the clays from the Palença clay sources [1], with clays of Miocene origin, which certainly were used to produce this pottery. The difference from A4 and A2 pastes is that in the latter case, albite was not transformed into anorthite and this means that neither the temperature nor the firing time were high enough for anorthite to be formed. The presence of large quantities of muscovite also implies lower temperatures of firing, never exciding 850 °C, as we will show later in this paper. Curves (iii) and (iv) from Fig. 5a were obtained from containers C5 and C2. The diffractogram pattern of C5 is quite similar to A4, so most probably is also from the Palença clay sources, using also temperatures of ~950 °C for firing the pottery. The important points in the diffractogram of C2 are the presence of albite, muscovite and even the detection of remains of calcite (CC, CaCO3), which exists in Palença clays in large amounts. So, for the Palença clays, whenever the ceramic's production was made at ~950 °C and for a long time, it enabled the formation of high quantities of anorthite, while for firing temperature that did not reach 850 °C [1], muscovite, albite and calcium carbonate still remain unmodified in the ceramic body. Curve (i) and (ii) of Fig. 5b are for red slip and grey wares, while curve (iii) of Fig. 5b is for cooking ware, show a different type ceramic paste. In all cases muscovite exists in well visible amounts. Curve (i) even exhibits calcite. Quartz is one the main components, and microcline, a potassium alumino silicate (Mic, K Al Si3O8) and muscovite could also be observed, the latter case indicating firing temperatures well below 850 °C. It is important to emphasize the great amount of
5.2. XRD studies The use of the XRD technique has provided important complementary information regarding the mineralogical composition of the Phoenician sherds studied in this work, when crossed it with the microRaman data. This allowed us to correlate the clay sources and ceramic bodies mineral compositions and also provided important insights of the kilns’ temperatures of firing. Fig. 5a shows the main diffractogram patterns for amphorae and containers while Fig. 5b presents similar data for red slip and grey ware, cooking ware and handmade ceramics. The two diffractograms for amphorae A4 and A2 exhibit remarkable differences: A4 curve exhibits huge amounts of anorthite (An, CaAl2Si2O8), diopside, (D, CaMgSi2O6) a calcium and magnesium silicate, hematite (H, Fe2O3) and also quartz (Q, SiO2), as major components. No muscovite, (M, KAl2(Si3Al)O10(OH)2), was detected in the A4 diffractogram. All these data point to a high temperature of the kiln, around 950 °C and long firing times of the pottery, to allow the formation of high amounts of anorthite and of the disappearance of muscovite. The presence of hematite indicates oxidizing conditions during the firing of the pottery, while the presence of minerals such as anorthite or diopside indicate the Miocene origin of the raw materials, since the calcium existed in the needed amounts to allow its formation 5
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 7. Scatterplot of Al/Si versus Ca/Si count ratios for the ceramic pastes and clays. The counts measured by XRF for each element were normalized by Si content, the main component of the body of the ceramics, in this way eliminating errors from empirical measurements and data treatment procedures [35].
The similarity of the diffractograms presented in Fig. 6 and, in most cases, for the Phoenician sherds under study, namely red slip and also handmade pottery, also points to the use of alluvium clays as raw materials for the pottery production. The use of alluvium clays for amphorae and containers cannot also be excluded.
Fig. 6. Diffractograms of the alluvium clays from Cais do Sodré: Curve (i) – 950 °C, 36 h firing time; Curve (ii) – 950 °C, 8 h firing time; Curve (iii) – 850 °C, 8 h; Curve (iv) – 750 °C, 8 h; Curve (iv) – clay as collected. The XRD peaks are assigned to: Quartz (Qz), Diopside (D), Anorthite (An), Albite (Alb), Muscovite (M), Microcline (Mic), Hematite (H), M (Muscovite) and Calcite (CC).
5.3. XRF studies
microcline in the cooking ware presented in curve (iii) of Fig. 5b, pointing to a different type of raw material being used for the cooking pottery. This diffractogram is compatible with a raw material of granitoid detrital origin with coarse grain [14,15]. Only in the case of the handmade ceramics (Fig. 5b, curve (iv)), anorthite could be detected, along with diopside and gehlenite, indicating high kiln's temperatures probably in the range of 850 to 950 °C in this case.
XRF was used to obtain the elemental composition for ceramic pastes of all the sherds, as powders, expressed as weight % of indicated oxides for major and minor elements, and parts per million (ppm) for trace elements. (Supplementary Table S1). In previous publications of our group [21,22,24] we have presented scatterplots of Al/Si versus Ca/Si count ratios (% wt ratio) measured by XRF. These representations allow us to distinguish the major groups of the studied materials and correlate these groups with the R parameter that will be referred below. In the present work, the scatterplot of Al/Si versus Ca/Si (% wt ratio) for the studied sherds as well as for clays, as collected and after firing, is portrayed in Fig. 7. Inside the larger ellipse, on the right, are the sherds in which the ceramic bodies have higher calcium contents, in accordance with several Raman spectra and diffractograms in the previous sections. The abscissa values associated with this ellipse are similar to the ones obtained for pastes obtained with Miocene clays from Palença clay sources [1]. In this large ellipse we also depict the XRF count ratios obtained for alluvium clays collected in the Tagus River banks, at Cais do Sodré area. Some other clays collected at Eastern part of Lisbon, namely Marvila and Chelas, could also be included in this plot area (data not presented). This observation together with the XRD patterns seems to point that the use of these clays as raw materials cannot be excluded. It is important to emphasize that the abscissa values of the larger ellipse (~0.1–~0.4) are different from those obtained for ceramic pastes produced with Western Lisbon clay sources, namely Prazeres, Lapa or Estrela areas, which cover a range of larger abscissa values [21], confirming that those traditional Lisbon clays were not the raw materials used for the ceramics studied here. Inside the small ellipse, on the left, are the sherds that possess ceramic bodies with reduced calcium content.
5.2.1. Clays as collected and fired The diffractogram pattern shown in curve (v) of Fig. 6 was obtained using the alluvium clay as collected in the Tagus River banks, in the Cais do Sodré area. Kaolinite, (K, Al2Si2O5(OH)4), that also exist in the Palença clays as collected, fully disappears when the clay was fired at 750 °C or more, as the diffractograms of Fig. 6 clearly show. Fig. 6 curves (iv) to (i) also presents one the main findings obtained by the use of XRD experiments. About 1000 mg of alluvium clay were fired in the electric furnace for 8 h at 950 °C, 850 °C and 750 °C. In the case of curve (i) the clay was fired at 950 °C during 36 h. This 950 °C temperature was selected because it is described in the literature as allowing the formation of anorthite and diopside, however without the formation of mullite [33,34], and no mullite could be detected in pattern (i). However one can see that large amounts of anorthite were formed in this prolonged firing of the clay, while the peaks for muscovite and albite disappeared. One can conclude that for both amphora A4 and container C5 sherds the temperature of the kiln did not exceed 950 °C and the difference for amphora A2 or container C2 was not caused by the use of a different raw material but rather to the use of higher firing temperatures in the former two cases. Different kiln temperatures were used, resulting in different mineral compositions of the ceramic bodies. 6
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
microcline. These data are compatible with the use of raw materials of granitoid detrital origin with coarse grain for this pottery production. So this study points out to multiple production centres, located both in Lisbon and Almada, not excluding other locations along the Tagus River.
Another parameter, the R index [1,21,22,24]. R = (SiO2 + Al2O3 + K2O) / CaO was used to evaluate the structural and most abundant components of the ceramic pastes, related to detrital/siliciclastic minerals (SiO2+Al2O3+K2O), towards the calcium oxide content (CaO), the chemical soluble fraction, and considered as a geological source indicator, allowing us to establish a characteristic range of values associated with the ceramic bodies and clays materials and compare them: in a simplified way, small values of R for samples with high contents of calcium, and larger values of R for low calcium contents of the ceramics pastes or clays. In our study, the ratio R lays in a range of ~25–~70, for the small ellipse, and R lays in a range of ~5–~14 for the large ellipse. The chemical composition, obtained by XRF analysis of sherds’ external faces (coloured and not coloured), is presented in the Supplementary Table S2. The iron content of the sherds, express as Fe2O3, varies from about 5.3 to 8.5 % wt, except for red slip tableware which has a Fe2O3 content ca. 13%, pointing out that the slip red coloration was achieved with iron containing minerals. This agrees with the detection of hematite, by micro-Raman spectra and XRD patterns, also points to oxidizing atmosphere conditions during firing. No manganese or almost no manganese was observed in the studied sherds. This observation contrasts with studies of coeval ceramics reported in literature [6, 36, 37] in which manganese minerals were responsible for darker colorations (black). In our case, the coloration of the grey tableware is obtained with reducing firing conditions, by closing up the kiln, and using low firing temperatures, as the presence of muscovite and albite, detected by XRD, attests.
Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgements Thanks are due to FCT, Portugal, for the funding of projects UID/ NAN/50024/2019 and M-ERA-MNT/0002/2015. We acknowledge the archaeologist Nuno Neto from Neoépica for giving us the alluvial clays collected in the Cais do Sodré area. Appendix A. Supplementary data Supplementary data to this article can be found online at https:// doi.org/10.1016/j.ceramint.2019.11.267. References [1] L.F.V. Ferreira, L. Barros, I.L.F. Machado, A. Gonzalez, T.M. Casimiro, M.F.C. Pereira, Spectroscopic characterization of the 8th to 7th BC amphorae from Almaraz site, Almada, Portugal, J. Archaeol. Sci. Rep. 21 (2018) 166–174, https:// doi.org/10.1016/j.jasrep.2018.07.005. [2] L. Barros, Introdução à Pré e Proto-História de Almada - Cadernos e Textos de Apoio 1, Câmara Municipal de Almada, 1998. [3] A.M. Arruda, Orientalizante e pós-orientalizante no sudoeste peninsular: geografia e cronologias. Actas del III Simposio Internacional de Arqueología de Mérida: protohistoria del Mediterráneo Occidental. Mérida 1 (2005), pp. 277–303. [4] E. de Sousa, A ocupação pré-romana da foz do Estuário do Tejo, Uniarq, 2014. [5] N.M. Neto, P.M. Rebelo, R.A. Ribeiro, M. Rocha, J.A.Z. López, Uma inscrição lapidar fenícia em Lisboa, Rev. Port. Arqueol. 19 (2016) 123–128. [6] S. Shoval, The application of LA-ICP-MS, EPMA and Raman micro-spectroscopy methods in the study of Iron Age Phoenician bichrome pottery at Tel Dor, J. Archaeol. Sci. Rep. 21 (2018) 938–951, https://doi.org/10.1016/j.jasrep.2017.03. 040. [7] A.M. Arruda, Los Fenicios en Portugal. Fenicios y mundo indigena en el centro y sur de Portugal (siglos VIII-VI a.C.), Universitat Pompeu Fabra, Barcelona, 1999-2000. [8] E. de Sousa, S. Guerra, A presença fenícia em Lisboa: novos vestígios descobertos no alto da colina do Castelo de São Jorge, Saguntum 50 (2018) 57–88, https://doi.org/ 10.7203/SAGVNTVM.50.10636. [9] J.L. Vallejo Sánchez, Las cerâmicas grises orientalizantes de la Península Ibérica, Actas del III Simposio Internacional de Arqueología de Mérida: protohistoria del Mediterráneo Occidental, 2 Anejos de Archivo Español de Arqueologia, Mérida, 2005, pp. 1149–1172. [10] E. de Sousa, E.A. Idade do Ferro em Lisboa, uma primeira aproximação a um faseamento cronológico e à evolução da cultura material, CuPAUAM 42 (2016) 167–185, https://doi.org/10.15366/cupauam2016.42.006. [11] E. de Sousa, E. A tale of two (?) cities: Lisbon and Almaraz at the dawn of the Iron Age, Rivista di Studi Fenici 46 (2018) 137–151. [12] E. de Sousa, The Iron Age occupation of Lisbon 56 Madrider Mitteilungen. Reichert Verlag Wiesbaden, 2015, pp. 109–138. [13] L.F. Vieira Ferreira, L. Barros, I. Ferreira Machado, M.F.C. Pereira, T.M. Casimiro, An archaeometric study of a Late Neolithic cup (and ceramic sherds) found at São Paulo Cave, Almada, Portugal, J. Raman Spectrosc. (2019), https://doi.org/10. 1002/jrs.5802 In press. [14] J. Pais, The neogene of the lower Tagus Basin (Portugal), Rev. Esp. Palaontol. 19 (2004) 229–242. [15] J. Pais, C. Moniz, J. Cabral, J.L. Cardoso, P. Legoinha, S. Machado, M.A. Morais, C. Lourenço, M.L. Ribeiro, P. Henriques, P. Falé, Noticia Explicativa da Carta Geológica de Portugal à Escala 1:50.000, Departamento de Geologia, Instituto Nacional de Engenharia, Tecnologia e Inovação, Lisboa, 2006. [16] C. Lepierre, Estudo Chimico e Technologico sobre a Cerâmica Portuguesa Moderna, Imprensa Nacional, Lisboa, 1899. [17] L. Fernandes, J. Bugalhão, P.A. Fernandes, Novo Museu de Lisboa. Debaixo dos nossos pés. Exhibition catalogue, Coord., D.L, 2017. [18] L.F. Vieira Ferreira, D.S. Conceição, D.P. Ferreira, L.F. Santos, T.M. Casimiro, I. Ferreira Machado, Portuguese 16th century tiles from Santo António da Charneca's kiln: a spectroscopic characterization of pigments, glazes and pastes, J. Raman Spectrosc. 45 (2014) 838–847, https://doi.org/10.1002/jrs.4551. [19] G. Zbyszewski, Carta Geológica dos Arredores de Lisboa na escala 1/50 000 – notícia explicativa da folha 4 – Lisboa, Serviços Geológicos de Portugal, Lisboa,
5.4. GSDR absorption studies Fig. S2 shows the ground state diffuse reflectance absorption spectra obtained for all the five groups of sherds of Fig. 2. All surfaces absorb in the UV part of the spectrum and the main differences exist in the Visible part of the spectrum. In previous publications details for the range of absorptions for each colour can be found [20–26]. 6. Conclusions The raw material from the alluvium clays of the Tagus River was studied as collected, or after firing for about 8 h at 750, 850 and 950 °C. Firing at 950 °C was also tested during 36 h. The mineralogical study of the ceramic bodies for the pottery sherds from of the São Jorge Castle's hill revealed several types of pastes: first, those where huge amounts of anorthite were detected, muscovite is absent and some diopside is also present. This means that the kiln temperature was of about 950 °C and firing was long enough to enable large amounts of anorthite to be formed. A second type of ceramic body evidences muscovite, albite, calcite, quartz, and microcline, indicating lower firing temperatures in the kiln, below 850 °C. These pastes are of Miocene origin. Red slip and handmade pottery exhibit this second type of paste in most cases, but amphorae and common containers are compatible both with the first and the second type, depending on the sample. One cannot exclude also that in some cases the amphorae and common containers could have been produced at Almaraz with the use of Palença clays, also compatible with the XRD patterns and the R parameters for these two groups. Some of the grey tableware exhibits a fine grain ceramic body and the R values are quite high and similar to other ceramics found in the Almaraz settlement. In this case Pliocene clays were used. Raman and XRD results as well as the chemical data pastes point out to local supply of the raw materials used in most ceramics of the São Jorge Castle's hill, but not for all samples. The cooking ware ceramic bodies are highly siliceous and evidence also high contents of 7
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
jrs.4914. [30] L. Fabrizi, L. Nigro, F. Spagnoli, P. Ballirano, C. De Vito, The Red Slip Ware from Motya (Sicily, Italy): A multi-analytical approach for determining the production technology and the nature of the raw materials, Ceram. Int. https://doi.org/10. 1016/j.ceramint.2019.09.136. [31] M. Ozçatal, M. Yaygingol, A. Issi, A. Kara, S. Turan, F. Ohyar, S. Pfeiffer Tas, I. Nastova, O. Grupce, B. Minceva-Sukarova, Characterization of lead glazed potteries from Smyrna (İzmir/Turkey) using multiple analytical techniques; Part II: body, Ceram. Int. 40 (2014) 2153–2160, https://doi.org/10.1016/j.ceramint.2013. 07.132. [32] I. Garofano, M.D. Robador, J.L. Perez-Rodriguez, J. Castaing, C. Pacheco, A. Durane, Ceramics from the Alcazar Palace in Seville (Spain) dated between the 11th and 15th centuries: compositions, technological features and degradation processes, J. Eur. Ceram. Soc. 35 (2015) 4307–4319, https://doi.org/10.1016/j. jeurceramsoc.2015.07.033. [33] N.Q. Liem, G. Sagon, V.X. Quang, H.V. Tan, Ph Colomban, Raman Study of microstructure, composition and processing of ancient Vietnamese (proto)porcelains and celadons (13-16th centuries), J. Raman Spectrosc. 31 (2000) 933–942, https:// doi.org/10.1002/1097-4555(200010)31:10<933::AID-JRS625>3.0.CO;2-0. [34] Ph Colomban, G. Sagon, X. Faurel, Differentiation of antique ceramics from the Raman spectra of their coloured glazes and paintings, J. Raman Spectrosc. 32 (2001) 351–360, https://doi.org/10.1002/jrs.704. [35] G. Simsek, F. Casadio, Ph Colomban, L. Bellot-Gurlet, K.T. Faber, G. Zelleke, V. Milande, E. Moinet, On-site identification of early Böttger red stoneware made at Meissen using portable XRF: 1, body analysis, J. Am. Ceram. Soc. 97 (2014) 2745–2754, https://doi.org/10.1111/jace.13032. [36] S.A. Centeno, V.I. Williams, N.C. Little, R.J. Speakman, Characterization of surface decorations in Prehispanic archaeological ceramics by Raman spectroscopy, FTIR, XRD and XRF, Vib. Spectrosc. 58 (2012) 119–124, https://doi.org/10.1016/j. vibspec.2011.11.004. [37] S. Akyuz, T. Akyuz, S. Basaran, C. Bolcal, A. Gulec, FT-IR and micro-Raman spectroscopic study of decorated potteries from VI and VII century BC, excavated in ancient Ainos – Turkey, J. Mol. Struct. 834–836 (2007) 150–153, https://doi.org/ 10.1016/j.molstruc.2006.12.011.
1963. [20] L.F. Vieira Ferreira, R. Varela Gomes, M.F.C. Pereira, L.F. Santos, I. Ferreira Machado Islamic ceramics in Portugal found at Silves Castle (8th to 13th c.): an archaeometric characterization, J. Archaeol. Sci.: Rep. 8 (2016) 434–443, https:// doi.org/10.1016/j.jasrep.2016.06.051. [21] L.F. Vieira Ferreira, A. Gonzalez, M.F.C. Pereira, L.F. Santos, T.M. Casimiro, D.P. Ferreira, D.S. Conceição, I. Ferreira Machado, Spectroscopy of 16th century Portuguese tin-glazed earthenware produced in the region of Lisbon, Ceram. Int. 41 (2015) 13433–13446, https://doi.org/10.1016/j.ceramint.2015.07.132. [22] L.F. Vieira Ferreira, I. Ferreira Machado, M.F.C. Pereira, T.M. Casimiro, Portuguese Blue-on-Blue 16th-17th c, Pottery. Archaeometry 60 (2018) 695–712, https://doi. org/10.1111/arcm.12336. [23] L.F. Vieira Ferreira, M. Varela Gomes, M.F.C. Pereira, L.F. Santos, I. Ferreira Machado, A multi-technique study for the spectroscopic characterization of the ceramics from Santa Maria do Castelo church (Torres Novas, Portugal), J. Archaeol. Sci.Rep. 6 (2016) 183–189, https://doi.org/10.1016/j.jasrep.2016.02.013. [24] L.F. Vieira Ferreira, I. Ferreira Machado, A. Gonzalez, M.F.C. Pereira, T.M. Casimiro, A new fifteenth-to-sixteenth-century pottery kiln on the Tagus basin, Portugal, Appl. Phys. A 124 (2018) 770–782, https://doi.org/10.1007/s00339-0182197-x. [25] L.F. Vieira Ferreira, D.S. Conceição, D.P. Ferreira, L.F. Santos, M.F.C. Pereira, T.M. Casimiro, I. Ferreira Machado, Portuguese tin-glazed earthenware from the 17th century. Part 2: a spectroscopic characterization of pigments, glazes and pastes of the three main production centers, Spectrochim. Acta, Part A 149 (2015) 285–294, https://doi.org/10.1016/j.saa.2015.04.090. [26] L.F. Vieira Ferreira, I.L. Ferreira Machado, Surface Photochemistry: organic molecules within nanocavities of Calixarenes, Curr. Drug Discov. Technol. 4 (2007) 229–245. [27] RRUFF Project Database, accessed in February 2019. [28] P. Ballirano, C. De Vito, L. Medeghini, S. Mignardi, V. Ferrini, P. Matthia, D. Bersani, P.P. Lottici, A combined use of optical microscopy, X-ray powder diffraction and micro-Raman spectroscopy for the characterization of ancient ceramic from Ebla (Syria), Ceram. Int. 40 (2014) 409–419. [29] D. Bersani, P.P. Lottici, Raman spectroscopy of minerals and mineral pigments in archaeometry, J. Raman Spectrosc. 47 (2016) 499–530, https://doi.org/10.1002/
8
Contents lists available at ScienceDirect
Ceramics International journal homepage: www.elsevier.com/locate/ceramint
An archaeometric study of the Phoenician ceramics found at the São Jorge Castle's hill in Lisbon L.F. Vieira Ferreiraa,∗, E. de Sousab, M.F.C. Pereirac, S. Guerrab, I. Ferreira Machadoa,d a
CQFM-Centro de Química-Física Molecular, IN-Institute for Nanosciences and Nanotechnologies, IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal b UNIARQ - Centro de Arqueologia da Universidade de Lisboa, Departamento de História, Faculdade de Letras - Universidade de Lisboa, Portugal c CERENA - Centro de Estudos em Recursos Naturais e Ambiente, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal d Polytechnic Institute of Portalegre, P-7300-110, Portalegre, Portugal
A R T I C LE I N FO
A B S T R A C T
Keywords: Phoenician ceramics Western-Phoenician colonies Lisbon-Phoenician ceramics Lisbon's Castle hill Clay materials
A detailed archaeometric study of Phoenician ceramics found in an excavation inside the medieval walls of São Jorge's Castle in Lisbon is described here. Thirty ceramic sherds were studied, grouped into six categories, namely amphorae, containers for domestic use, red slip wares, grey wares, cooking wares and also some indigenous tradition handmade wares. Micro-Raman, X-Ray Fluorescence Emission, X-Ray Diffraction and ground state diffuse reflectance absorption measurements were correlated and used as our main analytical techniques to perform this study. At least three totally different local clay sources were used to produce the here studied pottery, one of alluvial origin using clays collected along the river banks, and another one using clays probably extracted in the oriental part of the Castle's hill. Cooking-ware was made with the use of raw materials with sandy detrital origin. Evidence was also found showing that part of the amphorae, common containers, and grey wares were made with the same raw materials as used in the Phoenician kilns of Almaraz, located in the left margin of the Tagus River, roughly facing Lisbon's Castle hill. The temperatures of the kilns used to fire the amphorae and common containers was in most cases higher than the one used for firing red slip and grey tableware. A detailed laboratorial study of the alluvial clays fired at different temperatures and collected in the Tagus River banks, allowed us, in most cases, to establish the origin of the sources used to produce the Phoenician pottery found in Lisbon.
1. Introduction Following a recent study of the amphorae produced at the Phoenician archaeological site of Almaraz [1], located in the old part of the city of Almada, South shore of the Tagus River [2], a new archaeometric study was developed for the Phoenician ceramics found in the area of São Jorge Castle located in Lisbon, at the top of a hill in the right margin, facing the river. The Tagus Estuary occupation by Phoenician settlers started by the end of the 9th century beginnings of the 8th century B.C., based in radiocarbon dating's [3], although the artefacts recovered so far point to a latter chronology, between the late 8th/early 7th century B.C. A good description of the main orientalising settling places in the Tagus Estuary can be found in Ref. [4]. Recently, an important archaeological finding was made, a stele with Phoenician inscriptions, dated from the 7th century B.C [5]. This ∗
excavation was made not far from the local where the ceramics of this study were collected, and both are located in the South side of the Castle's hill. This stele, the oldest Phoenician epigraphic lapidary found in the Iberian Peninsula, is a proof of the importance of this settlement. The surface decoration of the Phoenician ceramics found in the Lisbon's Castle hill are quite similar to other Iron Age Phoenician settlements located in the Mediterranean, with monochromatic (red decorated) and dichromatic (black and red decorated) styles, the majority of which are geometrical [6]. In this study a detailed spectroscopic characterization of the surfaces and ceramic bodies of 30 Phoenician ceramic sherds from the Castle's hill in Lisbon is presented, and the correlation with the data obtained for clays from western and oriental geological formations in Lisbon, allowed to discuss the provenance of the raw materials used to produce the Lisbon Phoenician ceramics. The data presented in this study are also extremely significant considering that for the first time
Corresponding author. E-mail address: [email protected] (L.F. Vieira Ferreira).
https://doi.org/10.1016/j.ceramint.2019.11.267 Received 17 November 2019; Received in revised form 27 November 2019; Accepted 28 November 2019 0272-8842/ © 2019 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Please cite this article as: L.F. Vieira Ferreira, et al., Ceramics International, https://doi.org/10.1016/j.ceramint.2019.11.267
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 1. Phoenician ceramics recovered from the Tagus River estuary: some examples of red slip and grey tableware as well as an amphorae or containers. (from the Millennium BCP exhibition in Lisbon, 2014 - “Lisboa pré-clássica: um porto mediterrâneo no litoral atlântico”). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)
The Iron Age occupation of São Jorge's Hill is, without any doubt, one of the most important in the Portuguese territory. Several studies estimate that the main parts of this settlement were located in the hilltop and southern slope, extending over an area of about 11 ha [8] during the late 8th – 6th century B.C. Although its population entailed, originally, both foreign Western-Phoenician settlers and local communities, the archaeological evidences support that it was the Phoenician cultural matrix the one that prevailed during the first half of the 1st millennium B.C., as we can see by the overwhelming majority of wheelmade ceramic productions of Phoenician tradition, the presence of architectural elements such as orthogonal construction plans using adobe bricks or “taipa” for lifting the walls [11], and the presence of inscriptions in Phoenician language and writing, among which the extraordinary funerary stele previously referred [5]. The compiled data seems to suggest that the habitat located in São Jorge's Hill may have actually been a Phoenician colony during the Iron Age earliest stages [11,12]. The study collected five sherds of each of the ceramic categories retrieved in primary layers dating from the 7th and 6th centuries B.C. from Largo de Santa Cruz: amphorae, common ware (containers), red slip ware, grey ware, cooking ware and handmade wares.
these analytical approaches were applied to the entire ceramic categories used during the early Iron Age in Western Iberia, enabling therefore a comparison of different techniques used in the production kilns. Some representative examples of Phoenician ceramics found in Lisbon are shown in Fig. 1. 2. Archaeological context and framework Archaeological discoveries carried out during the last decade have enlightened the importance of the Phoenician presence in the Tagus area, particularly in Lisbon, during the early 1st millennium B.C. Even though this presence had already been noticed and valued since the late 20th century [7], the absence of detailed stratigraphic sequences concerning the first moments of human occupation at São Jorge's Hill, in Lisbon, hampered a more substantial reading of the impact that the arrival of these settlers had on the indigenous communities which previously inhabited the area. Thanks to recent urban archaeological interventions, these shortcomings have been progressively exceeded. For the purpose of this paper we should highlight recent excavations carried out in the hilltop of São Jorge's Hill, in Largo de Santa Cruz do Castelo, which brought to light a series of preserved archaeological contexts dated from the 7th to the 5th centuries B.C [8]. The importance of these findings lies in the fact that it enabled one to characterize the local material culture assemblages, which are undeniably related with the Phoenician cultural matrix. The foreign community that settled in São Jorge's Hill during the late 8th/early 7th centuries B.C. was probably originated from the Phoenician settlements in Southern Andalusia, some of which were founded at least 150 years earlier. The constant interactions with local communities during this time naturally brought important cultural changes to both sides. A classic example of this phenomenon is known as the Phoenician “grey wares”, practically unique in the Iberian Peninsula, but unknown in other Phoenician settlements in Central and Eastern Mediterranean, which were the result of a symbiotic interaction that gathered both Phoenician production techniques and local Iberian aesthetic traditions [9]. Common features can be observed in the fine wares (red slip ware and grey ware), containers and transport vessels (Cruz del Negro type urns, pithoi and amphorae) and in the cookingwares, even if the morphological shapes and decorations may vary [10]. Nonetheless, the complex process of the Orientalisation of the Portuguese coast also involves other agents, namely the indigenous communities that previously resided in the area. The presence of these individuals is testified through handmade wares, which follow the previous local Late Bronze Age traditions, and that are an important part of the early Iron Age pottery assemblages found in São Jorge's Hill, even if its representativeness is progressively reduced over the centuries [8,11].
3. Geological setting The Lisbon region presents two different geological areas: the first one is located North of Tagus River, where one can find Cretaceous, Paleogenic (basalt complex of Lisbon) and Neogenic (Miocene) formations [13]. South of Tagus River also some Miocenic outcrops can also be found, namely Almada, Trafaria and Costa da Caparica. A second region South of Tagus River should also be mentioned, quite different from the first one, and corresponds to Pliocene areas [13,14]. Several lithologies, including Cretaceous and Paleogenic rocks exposed in Lisbon district are known as good sources of raw materials (ornamental and building stones, aggregates, ceramic, glass …) from pre-historical times until nowadays (Museu de Lisboa, 2017). “Prazeres Clays” formation—Aquitanian to Lower Burdigalian; “Brick Oven Clays” formation—Burdigalian; “Xabregas Blue Clays” formation—Upper Langhian and Serravallian) constitute very important deposits [15,16] traditionally grouped as west Lisbon and east Lisbon clay sources, for white or red clays [16]. Alternative sources of historical ceramic products are modern terrace and alluvial formations in both margins of Tagus River and their tributaries [17]. Mineralogy of Miocene raw materials (claystones or marly limestones), collected at several industrial and historical reference sites, including samples from IST Geosciences Museum, is remarkably constant, although the amount of calcite and iron oxides changes from place to place. Quartz, muscovite and/or illite and kaolinite are the main constituents of the Pliocene raw materials [18,19]. 2
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
and data processing, namely the baseline correction was done when needed, with the Wire 4 software or with the LabSpec software from Jobin Yvon. Ceramics (cup and sherds) were analysed either from the surface of the cup or from ground sherd fragments (10–20 mg). Further details about the use of this spectroscopic tool can be found in Refs. [20–25]. 4.2.2. X-ray fluorescence The elemental chemical composition of ceramic pastes was also determined by X-ray fluorescence with the use of a Niton XL3T GOLDD spectrometer (Thermo Scientific) with a 50 kV/200 μA X-ray generator, 3 mm spot diameter for excitation. Further details can be found in Refs. [20–25]. 4.2.3. X-ray diffraction The identification of the ceramic body powder crystalline phases was carried out by using of a X-Ray diffractometer at CERENA (Panalytical X'PERT PRO model), with CuKα radiation. The measurement parameters used were: 2θ (5–70°); step size 2θ = 0.033° and a scan step time of 80 s with generator settings of 35 mA and 40 kV. In the case of XRD measurements only about 10 mg of powder sample are needed to perform an experiment, so it can be considered a quasi-nondestructive technique. The estimated penetration depth is about 30 μm. 4.2.4. Ground state diffuse reflectance absorption spectroscopy Ground-state absorption studies were performed using a homemade diffuse reflectance setup, as described in Refs. [20–26], with the use of three standards, barium sulfate powder and Spectralon white and grey disks.
Fig. 2. Phoenician ceramic sherds from Lisbon's castle area.
4. Materials and methods 4.1. Samples
4.3. General
30 pottery sherds were spectroscopically studied and the experimental results are grouped into six categories, as shown in Fig. 2. Sherds A1 to A5 are from amphorae, with or without a beige engobe; sherds C1 to C5 are from containers for domestic use, also with beige engobe; sherds R1 to R5 are from red slip tableware and all present a well visible red superficial coloration, some darker than others; sherds G1 to G5 are from grey tableware, dark ceramic body and even darker surface; K1 to K5 sherds are examples of cooking ware and its surface evidences black carbon deposits certainly due to the contact with the flames during food preparation. Finally samples H1 to H5 are considered to be indigenous tradition handmade wares and its ceramic body presents coarse grains. A simple visual observation of the ceramic bodies indicates that the used raw materials were extracted from different clay sources.
In what regards the firing procedure of the collected clay samples at laboratory level, all samples were placed in porcelain crucibles and submitted to a heat treatment in a high temperature chamber electric furnace (Nabertherm, Germany), in a range of 750 °C to 950 °C from 8 up to 36 h, with a heating rate of about 5 °C/min, and were allowed to return to room temperature with an identical rate. Figures presented as supplementary material were obtained with an Olympus OMD camera, using a macro lens. 5. Results and discussion 5.1. Μicro-Raman spectroscopic data Micro-Raman spectroscopy was used to characterize the surface of the sherds and also of the ceramic bodies.
4.2. Experimental techniques under use 5.1.1. Surface pigments of the Phoenician sherds The micro-Raman spectra obtained for the surface of the Phoenician sherds (beige engobe for the amphorae and common containers), red or dark red for the red slip tableware, black or dark grey for the grey tableware, dark braun or black for the cooking ware and reddish or dark braun for the handmade wares are shown in Fig. 3i)–vii), while Fig. 4i)–vii) presents data for the ceramic bodies analysed from powders removed from the sherds. Curve (i) in Fig. 3 is from the superficial engobe of the A4 sherd. All amphora sherds have a red/greyish ceramic body and are covered with a beige engobe, which in some cases was partially detached. Several peaks located at 245, 439 and 611 cm−1 show the presence of rutile (TiO2), but the peak at 146 cm−1 evidences the presence of anatase. The other peaks of anatase could not be detected because they overlap the peaks of rutile which are stronger. Most probably some anatase in the initial slip was transformed into rutile whenever the kiln temperature was enough high to perform that transformation, as we will see later in the analysis of the diffractogram patterns.
4.2.1. Micro-Raman spectrometry Micro-Raman measurements were carried out with the with use of a Renishaw InVia confocal Raman microscope, in a back-scattering micro-configuration, A powerful 300 mW, 532 nm laser excitation (Cobolt, Samba model) and 100×, 50×, 20×, 10× and 5× objectives in a Leica microscope. In most spectral collection was made with the use of a 50× long working distance objective. The spectral resolution of the Raman spectrometer was ~1 cm−1. A second excitation laser was used (λexc = 785 nm) which enabled us to identify some minerals in the ceramic body which was not achieved with the green excitation, namely calcium carbonate. The Renishaw equipment has accurate confocal capabilities, enabling in-depth studies from the surface to about 150 μm. All Raman spectra were recorded at least in 5 different spots for each sample, and all spectra presented in this paper are representative of the samples under study. Data acquisition was performed with the Renishaw software Wire 4 3
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 4. Micro-Raman spectra from the Phoenician ceramic bodies i) Amphorae A4; (ii) Container C3; (iii) Red slip ware R5; (iv) Red slip ware R5; (v) Grey ware G3; (vi) Cooking ware K1: (vii) Handmade ceramics H5. The Raman signals are assigned to: Anorthite (An), Albite (Alb), Calcite (CC), Hematite (H), Magnetite (M), Anatase (A) and Carbon Black (CB).
Fig. 3. Micro-Raman spectra from the sherds' surfaces. (i) Amphorae A4; (ii) Amphorae A2; (iii) Container C3; (iv) Red slip ware R2; (v) Grey ware G1; (vi) Cooking ware K3: (vii) Cooking ware K4. The Raman signals are assigned to: Rutile (R), Anatase (A), Albite (Alb), Carbon Black (CB), Hematite (H) and Quartz (Qz).
5.1.2. Ceramic bodies Important information regarding the firing conditions and even origins of the pottery sherds from the Phoenician ceramics from Lisbon Castle could be obtained from the micro-Raman study of the ceramic bodies. Curve (i) from Fig. 4 is from sherd A4 and clearly exhibits anorthite. Anorthite is a calcium alumino-silicate (CaAl2Si2O8) and it requires high temperatures of the kiln to be formed, about 950 °C [28–30]. The main peaks are located at 193, 279, 478, 506, 558, and 970 cm−1. Curve (ii) is from sherd C3, a container. One can clearly identify calcite (CC, peaks at 152, 715, 1080 cm−1). Also albite peaking at 152, 285, 475, 509 cm−1 could be detected as well as some carbon black at longer wavenumbers. The detection of albite shows that the firing temperature of this paste did not reach values high enough for the transformation of albite into anorthite to occur, consistent with firing temperatures well below 950 °C, even enabling the “survival” of calcite, well known to completely disappear at ~850 °C [31,32]. Curves (iii) and (iv) were obtained for sherd R5, exciting at different spots. In the case of curve (iii), hematite (H, peaking at 118, 229, 293, 408, 505 and 1333 cm−1), magnetite (M, 678 cm−1) and some carbon black could be identified. The main difference for curve (iv) is that Anatase is superimposed onto the hematite Raman peaks (A, 150, 399, 505 and 628 cm−1). The white colour of anatase certainly makes the red colour brighter. Curve (v) for the grey ware exhibits huge amounts of carbon black and small quantities of albite. Curves (vi) and (vii) from Fig. 4 also provide important information because in all cases albite is the dominant mineral in the ceramic body. The fact that this mineral exists in all these ceramic bodies shows again that the kiln's temperature was not high enough for them to be transformed into anorthite. XRD studies presented later in this paper will
Curve (ii) in Fig. 3 is from the surface of amphora A2. Although a small peak of anatase could be detected, the main Raman peaks are from albite, a sodium feldspar (Alb, peaks being located at 165, 290, 406, 476, 508, 760 and 810 cm−1), and also carbon black (CB, peaks at about 1357 and 1560 cm−1). These peaks are more representative of the ceramic body than of the engobe, which puts in evidence the cracks all over the surface. Curve (iii) in Fig. 3 is from a beige zone of the surface of container C3, and again the dominant peaks belong to rutile although a small amount of anatase can be seen at 144 cm−1. Clearly the engobe is dominated by the presence of the rutile polymorph of titanium dioxide. Curve (iv) in Fig. 3 is from a red area of the surface of R2 sherd and the peaks were detected at 121, 220, 288, 403, 460, 611, 656 and 1316 cm−1. These Raman peaks clearly identify hematite (Fe2O3) [27], here associated to the red coloration of other parts of the cup's surface and also reveal the presence of quartz (Q, 461 cm−1). Small amounts of carbon black could also be detected, and these of course are associated with the darkening of the red surface. Curve (v) of Fig. 3 refers to the black or dark/grey surface, where the presence albite and anatase is clear as well as large amounts of carbon black peaking at 1375 and 1607 cm−1. This large amount of carbon black is of course the responsible for the black coloration of the surface. In Fig. 3, curves (vi) for K3 and (vii) for K4 identify the presence of quartz (Q), with peaks at 124, 194, 355, 461 and 1169 cm−1 that clearly indicate the crystalline silica of these samples. Also anatase (A, peaks at 145, 399, 633 cm−1) could be detected in this cooking ware, as well as large Raman signatures of carbon black. 4
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 5a. Diffractograms from Phoenicians ceramics of Lisbon: two amphora A4 and A2, and two common vessels (containers) C5 and C2. The XRD peaks are assigned to: Quartz (Qz), Anorthite (An), Diopside (D), Hematite (H), M (Muscovite), Albite (Alb), Microcline (Mic), and Calcite (CC).
Fig. 5b. Diffractograms from Phoenicians ceramics of Lisbon: Curve (i) – Red slip ware R5; Curve (ii) – Grey ware G3; Curve (iii) – Cooking ware K3; Curve (iv) – Handmade ceramics H3. The XRD peaks are assigned to: M (Muscovite), Quartz (Qz), Albite (Alb), Calcite (CC), Hematite (H), Anorthite (An), Diopside (D), Gehlenite (G) and Microcline (Mic).
show us that all these ceramic bodies were formed by the use of Miocenic clays. For temperatures below or around 850 °C anorthite was not formed and the minerals existing in the initial raw material remain unchanged, as is the case of albite. Curve (v) clearly indicates the presence of black carbon in the ceramic body of the grey tableware. No specific curves regarding the spectroscopic Raman signature of quartz are presented in Fig. 4, however quartz exists in all the studied ceramic bodies.
after firing. In the case of curve (ii) of Fig. 5a, one can note the presence of muscovite (M) and also of albite, a sodium alumino-silicate. (Alb, NaAlSi3O8). These minerals exist in the clays from the Palença clay sources [1], with clays of Miocene origin, which certainly were used to produce this pottery. The difference from A4 and A2 pastes is that in the latter case, albite was not transformed into anorthite and this means that neither the temperature nor the firing time were high enough for anorthite to be formed. The presence of large quantities of muscovite also implies lower temperatures of firing, never exciding 850 °C, as we will show later in this paper. Curves (iii) and (iv) from Fig. 5a were obtained from containers C5 and C2. The diffractogram pattern of C5 is quite similar to A4, so most probably is also from the Palença clay sources, using also temperatures of ~950 °C for firing the pottery. The important points in the diffractogram of C2 are the presence of albite, muscovite and even the detection of remains of calcite (CC, CaCO3), which exists in Palença clays in large amounts. So, for the Palença clays, whenever the ceramic's production was made at ~950 °C and for a long time, it enabled the formation of high quantities of anorthite, while for firing temperature that did not reach 850 °C [1], muscovite, albite and calcium carbonate still remain unmodified in the ceramic body. Curve (i) and (ii) of Fig. 5b are for red slip and grey wares, while curve (iii) of Fig. 5b is for cooking ware, show a different type ceramic paste. In all cases muscovite exists in well visible amounts. Curve (i) even exhibits calcite. Quartz is one the main components, and microcline, a potassium alumino silicate (Mic, K Al Si3O8) and muscovite could also be observed, the latter case indicating firing temperatures well below 850 °C. It is important to emphasize the great amount of
5.2. XRD studies The use of the XRD technique has provided important complementary information regarding the mineralogical composition of the Phoenician sherds studied in this work, when crossed it with the microRaman data. This allowed us to correlate the clay sources and ceramic bodies mineral compositions and also provided important insights of the kilns’ temperatures of firing. Fig. 5a shows the main diffractogram patterns for amphorae and containers while Fig. 5b presents similar data for red slip and grey ware, cooking ware and handmade ceramics. The two diffractograms for amphorae A4 and A2 exhibit remarkable differences: A4 curve exhibits huge amounts of anorthite (An, CaAl2Si2O8), diopside, (D, CaMgSi2O6) a calcium and magnesium silicate, hematite (H, Fe2O3) and also quartz (Q, SiO2), as major components. No muscovite, (M, KAl2(Si3Al)O10(OH)2), was detected in the A4 diffractogram. All these data point to a high temperature of the kiln, around 950 °C and long firing times of the pottery, to allow the formation of high amounts of anorthite and of the disappearance of muscovite. The presence of hematite indicates oxidizing conditions during the firing of the pottery, while the presence of minerals such as anorthite or diopside indicate the Miocene origin of the raw materials, since the calcium existed in the needed amounts to allow its formation 5
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
Fig. 7. Scatterplot of Al/Si versus Ca/Si count ratios for the ceramic pastes and clays. The counts measured by XRF for each element were normalized by Si content, the main component of the body of the ceramics, in this way eliminating errors from empirical measurements and data treatment procedures [35].
The similarity of the diffractograms presented in Fig. 6 and, in most cases, for the Phoenician sherds under study, namely red slip and also handmade pottery, also points to the use of alluvium clays as raw materials for the pottery production. The use of alluvium clays for amphorae and containers cannot also be excluded.
Fig. 6. Diffractograms of the alluvium clays from Cais do Sodré: Curve (i) – 950 °C, 36 h firing time; Curve (ii) – 950 °C, 8 h firing time; Curve (iii) – 850 °C, 8 h; Curve (iv) – 750 °C, 8 h; Curve (iv) – clay as collected. The XRD peaks are assigned to: Quartz (Qz), Diopside (D), Anorthite (An), Albite (Alb), Muscovite (M), Microcline (Mic), Hematite (H), M (Muscovite) and Calcite (CC).
5.3. XRF studies
microcline in the cooking ware presented in curve (iii) of Fig. 5b, pointing to a different type of raw material being used for the cooking pottery. This diffractogram is compatible with a raw material of granitoid detrital origin with coarse grain [14,15]. Only in the case of the handmade ceramics (Fig. 5b, curve (iv)), anorthite could be detected, along with diopside and gehlenite, indicating high kiln's temperatures probably in the range of 850 to 950 °C in this case.
XRF was used to obtain the elemental composition for ceramic pastes of all the sherds, as powders, expressed as weight % of indicated oxides for major and minor elements, and parts per million (ppm) for trace elements. (Supplementary Table S1). In previous publications of our group [21,22,24] we have presented scatterplots of Al/Si versus Ca/Si count ratios (% wt ratio) measured by XRF. These representations allow us to distinguish the major groups of the studied materials and correlate these groups with the R parameter that will be referred below. In the present work, the scatterplot of Al/Si versus Ca/Si (% wt ratio) for the studied sherds as well as for clays, as collected and after firing, is portrayed in Fig. 7. Inside the larger ellipse, on the right, are the sherds in which the ceramic bodies have higher calcium contents, in accordance with several Raman spectra and diffractograms in the previous sections. The abscissa values associated with this ellipse are similar to the ones obtained for pastes obtained with Miocene clays from Palença clay sources [1]. In this large ellipse we also depict the XRF count ratios obtained for alluvium clays collected in the Tagus River banks, at Cais do Sodré area. Some other clays collected at Eastern part of Lisbon, namely Marvila and Chelas, could also be included in this plot area (data not presented). This observation together with the XRD patterns seems to point that the use of these clays as raw materials cannot be excluded. It is important to emphasize that the abscissa values of the larger ellipse (~0.1–~0.4) are different from those obtained for ceramic pastes produced with Western Lisbon clay sources, namely Prazeres, Lapa or Estrela areas, which cover a range of larger abscissa values [21], confirming that those traditional Lisbon clays were not the raw materials used for the ceramics studied here. Inside the small ellipse, on the left, are the sherds that possess ceramic bodies with reduced calcium content.
5.2.1. Clays as collected and fired The diffractogram pattern shown in curve (v) of Fig. 6 was obtained using the alluvium clay as collected in the Tagus River banks, in the Cais do Sodré area. Kaolinite, (K, Al2Si2O5(OH)4), that also exist in the Palença clays as collected, fully disappears when the clay was fired at 750 °C or more, as the diffractograms of Fig. 6 clearly show. Fig. 6 curves (iv) to (i) also presents one the main findings obtained by the use of XRD experiments. About 1000 mg of alluvium clay were fired in the electric furnace for 8 h at 950 °C, 850 °C and 750 °C. In the case of curve (i) the clay was fired at 950 °C during 36 h. This 950 °C temperature was selected because it is described in the literature as allowing the formation of anorthite and diopside, however without the formation of mullite [33,34], and no mullite could be detected in pattern (i). However one can see that large amounts of anorthite were formed in this prolonged firing of the clay, while the peaks for muscovite and albite disappeared. One can conclude that for both amphora A4 and container C5 sherds the temperature of the kiln did not exceed 950 °C and the difference for amphora A2 or container C2 was not caused by the use of a different raw material but rather to the use of higher firing temperatures in the former two cases. Different kiln temperatures were used, resulting in different mineral compositions of the ceramic bodies. 6
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
microcline. These data are compatible with the use of raw materials of granitoid detrital origin with coarse grain for this pottery production. So this study points out to multiple production centres, located both in Lisbon and Almada, not excluding other locations along the Tagus River.
Another parameter, the R index [1,21,22,24]. R = (SiO2 + Al2O3 + K2O) / CaO was used to evaluate the structural and most abundant components of the ceramic pastes, related to detrital/siliciclastic minerals (SiO2+Al2O3+K2O), towards the calcium oxide content (CaO), the chemical soluble fraction, and considered as a geological source indicator, allowing us to establish a characteristic range of values associated with the ceramic bodies and clays materials and compare them: in a simplified way, small values of R for samples with high contents of calcium, and larger values of R for low calcium contents of the ceramics pastes or clays. In our study, the ratio R lays in a range of ~25–~70, for the small ellipse, and R lays in a range of ~5–~14 for the large ellipse. The chemical composition, obtained by XRF analysis of sherds’ external faces (coloured and not coloured), is presented in the Supplementary Table S2. The iron content of the sherds, express as Fe2O3, varies from about 5.3 to 8.5 % wt, except for red slip tableware which has a Fe2O3 content ca. 13%, pointing out that the slip red coloration was achieved with iron containing minerals. This agrees with the detection of hematite, by micro-Raman spectra and XRD patterns, also points to oxidizing atmosphere conditions during firing. No manganese or almost no manganese was observed in the studied sherds. This observation contrasts with studies of coeval ceramics reported in literature [6, 36, 37] in which manganese minerals were responsible for darker colorations (black). In our case, the coloration of the grey tableware is obtained with reducing firing conditions, by closing up the kiln, and using low firing temperatures, as the presence of muscovite and albite, detected by XRD, attests.
Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgements Thanks are due to FCT, Portugal, for the funding of projects UID/ NAN/50024/2019 and M-ERA-MNT/0002/2015. We acknowledge the archaeologist Nuno Neto from Neoépica for giving us the alluvial clays collected in the Cais do Sodré area. Appendix A. Supplementary data Supplementary data to this article can be found online at https:// doi.org/10.1016/j.ceramint.2019.11.267. References [1] L.F.V. Ferreira, L. Barros, I.L.F. Machado, A. Gonzalez, T.M. Casimiro, M.F.C. Pereira, Spectroscopic characterization of the 8th to 7th BC amphorae from Almaraz site, Almada, Portugal, J. Archaeol. Sci. Rep. 21 (2018) 166–174, https:// doi.org/10.1016/j.jasrep.2018.07.005. [2] L. Barros, Introdução à Pré e Proto-História de Almada - Cadernos e Textos de Apoio 1, Câmara Municipal de Almada, 1998. [3] A.M. Arruda, Orientalizante e pós-orientalizante no sudoeste peninsular: geografia e cronologias. Actas del III Simposio Internacional de Arqueología de Mérida: protohistoria del Mediterráneo Occidental. Mérida 1 (2005), pp. 277–303. [4] E. de Sousa, A ocupação pré-romana da foz do Estuário do Tejo, Uniarq, 2014. [5] N.M. Neto, P.M. Rebelo, R.A. Ribeiro, M. Rocha, J.A.Z. López, Uma inscrição lapidar fenícia em Lisboa, Rev. Port. Arqueol. 19 (2016) 123–128. [6] S. Shoval, The application of LA-ICP-MS, EPMA and Raman micro-spectroscopy methods in the study of Iron Age Phoenician bichrome pottery at Tel Dor, J. Archaeol. Sci. Rep. 21 (2018) 938–951, https://doi.org/10.1016/j.jasrep.2017.03. 040. [7] A.M. Arruda, Los Fenicios en Portugal. Fenicios y mundo indigena en el centro y sur de Portugal (siglos VIII-VI a.C.), Universitat Pompeu Fabra, Barcelona, 1999-2000. [8] E. de Sousa, S. Guerra, A presença fenícia em Lisboa: novos vestígios descobertos no alto da colina do Castelo de São Jorge, Saguntum 50 (2018) 57–88, https://doi.org/ 10.7203/SAGVNTVM.50.10636. [9] J.L. Vallejo Sánchez, Las cerâmicas grises orientalizantes de la Península Ibérica, Actas del III Simposio Internacional de Arqueología de Mérida: protohistoria del Mediterráneo Occidental, 2 Anejos de Archivo Español de Arqueologia, Mérida, 2005, pp. 1149–1172. [10] E. de Sousa, E.A. Idade do Ferro em Lisboa, uma primeira aproximação a um faseamento cronológico e à evolução da cultura material, CuPAUAM 42 (2016) 167–185, https://doi.org/10.15366/cupauam2016.42.006. [11] E. de Sousa, E. A tale of two (?) cities: Lisbon and Almaraz at the dawn of the Iron Age, Rivista di Studi Fenici 46 (2018) 137–151. [12] E. de Sousa, The Iron Age occupation of Lisbon 56 Madrider Mitteilungen. Reichert Verlag Wiesbaden, 2015, pp. 109–138. [13] L.F. Vieira Ferreira, L. Barros, I. Ferreira Machado, M.F.C. Pereira, T.M. Casimiro, An archaeometric study of a Late Neolithic cup (and ceramic sherds) found at São Paulo Cave, Almada, Portugal, J. Raman Spectrosc. (2019), https://doi.org/10. 1002/jrs.5802 In press. [14] J. Pais, The neogene of the lower Tagus Basin (Portugal), Rev. Esp. Palaontol. 19 (2004) 229–242. [15] J. Pais, C. Moniz, J. Cabral, J.L. Cardoso, P. Legoinha, S. Machado, M.A. Morais, C. Lourenço, M.L. Ribeiro, P. Henriques, P. Falé, Noticia Explicativa da Carta Geológica de Portugal à Escala 1:50.000, Departamento de Geologia, Instituto Nacional de Engenharia, Tecnologia e Inovação, Lisboa, 2006. [16] C. Lepierre, Estudo Chimico e Technologico sobre a Cerâmica Portuguesa Moderna, Imprensa Nacional, Lisboa, 1899. [17] L. Fernandes, J. Bugalhão, P.A. Fernandes, Novo Museu de Lisboa. Debaixo dos nossos pés. Exhibition catalogue, Coord., D.L, 2017. [18] L.F. Vieira Ferreira, D.S. Conceição, D.P. Ferreira, L.F. Santos, T.M. Casimiro, I. Ferreira Machado, Portuguese 16th century tiles from Santo António da Charneca's kiln: a spectroscopic characterization of pigments, glazes and pastes, J. Raman Spectrosc. 45 (2014) 838–847, https://doi.org/10.1002/jrs.4551. [19] G. Zbyszewski, Carta Geológica dos Arredores de Lisboa na escala 1/50 000 – notícia explicativa da folha 4 – Lisboa, Serviços Geológicos de Portugal, Lisboa,
5.4. GSDR absorption studies Fig. S2 shows the ground state diffuse reflectance absorption spectra obtained for all the five groups of sherds of Fig. 2. All surfaces absorb in the UV part of the spectrum and the main differences exist in the Visible part of the spectrum. In previous publications details for the range of absorptions for each colour can be found [20–26]. 6. Conclusions The raw material from the alluvium clays of the Tagus River was studied as collected, or after firing for about 8 h at 750, 850 and 950 °C. Firing at 950 °C was also tested during 36 h. The mineralogical study of the ceramic bodies for the pottery sherds from of the São Jorge Castle's hill revealed several types of pastes: first, those where huge amounts of anorthite were detected, muscovite is absent and some diopside is also present. This means that the kiln temperature was of about 950 °C and firing was long enough to enable large amounts of anorthite to be formed. A second type of ceramic body evidences muscovite, albite, calcite, quartz, and microcline, indicating lower firing temperatures in the kiln, below 850 °C. These pastes are of Miocene origin. Red slip and handmade pottery exhibit this second type of paste in most cases, but amphorae and common containers are compatible both with the first and the second type, depending on the sample. One cannot exclude also that in some cases the amphorae and common containers could have been produced at Almaraz with the use of Palença clays, also compatible with the XRD patterns and the R parameters for these two groups. Some of the grey tableware exhibits a fine grain ceramic body and the R values are quite high and similar to other ceramics found in the Almaraz settlement. In this case Pliocene clays were used. Raman and XRD results as well as the chemical data pastes point out to local supply of the raw materials used in most ceramics of the São Jorge Castle's hill, but not for all samples. The cooking ware ceramic bodies are highly siliceous and evidence also high contents of 7
Ceramics International xxx (xxxx) xxx–xxx
L.F. Vieira Ferreira, et al.
jrs.4914. [30] L. Fabrizi, L. Nigro, F. Spagnoli, P. Ballirano, C. De Vito, The Red Slip Ware from Motya (Sicily, Italy): A multi-analytical approach for determining the production technology and the nature of the raw materials, Ceram. Int. https://doi.org/10. 1016/j.ceramint.2019.09.136. [31] M. Ozçatal, M. Yaygingol, A. Issi, A. Kara, S. Turan, F. Ohyar, S. Pfeiffer Tas, I. Nastova, O. Grupce, B. Minceva-Sukarova, Characterization of lead glazed potteries from Smyrna (İzmir/Turkey) using multiple analytical techniques; Part II: body, Ceram. Int. 40 (2014) 2153–2160, https://doi.org/10.1016/j.ceramint.2013. 07.132. [32] I. Garofano, M.D. Robador, J.L. Perez-Rodriguez, J. Castaing, C. Pacheco, A. Durane, Ceramics from the Alcazar Palace in Seville (Spain) dated between the 11th and 15th centuries: compositions, technological features and degradation processes, J. Eur. Ceram. Soc. 35 (2015) 4307–4319, https://doi.org/10.1016/j. jeurceramsoc.2015.07.033. [33] N.Q. Liem, G. Sagon, V.X. Quang, H.V. Tan, Ph Colomban, Raman Study of microstructure, composition and processing of ancient Vietnamese (proto)porcelains and celadons (13-16th centuries), J. Raman Spectrosc. 31 (2000) 933–942, https:// doi.org/10.1002/1097-4555(200010)31:10<933::AID-JRS625>3.0.CO;2-0. [34] Ph Colomban, G. Sagon, X. Faurel, Differentiation of antique ceramics from the Raman spectra of their coloured glazes and paintings, J. Raman Spectrosc. 32 (2001) 351–360, https://doi.org/10.1002/jrs.704. [35] G. Simsek, F. Casadio, Ph Colomban, L. Bellot-Gurlet, K.T. Faber, G. Zelleke, V. Milande, E. Moinet, On-site identification of early Böttger red stoneware made at Meissen using portable XRF: 1, body analysis, J. Am. Ceram. Soc. 97 (2014) 2745–2754, https://doi.org/10.1111/jace.13032. [36] S.A. Centeno, V.I. Williams, N.C. Little, R.J. Speakman, Characterization of surface decorations in Prehispanic archaeological ceramics by Raman spectroscopy, FTIR, XRD and XRF, Vib. Spectrosc. 58 (2012) 119–124, https://doi.org/10.1016/j. vibspec.2011.11.004. [37] S. Akyuz, T. Akyuz, S. Basaran, C. Bolcal, A. Gulec, FT-IR and micro-Raman spectroscopic study of decorated potteries from VI and VII century BC, excavated in ancient Ainos – Turkey, J. Mol. Struct. 834–836 (2007) 150–153, https://doi.org/ 10.1016/j.molstruc.2006.12.011.
1963. [20] L.F. Vieira Ferreira, R. Varela Gomes, M.F.C. Pereira, L.F. Santos, I. Ferreira Machado Islamic ceramics in Portugal found at Silves Castle (8th to 13th c.): an archaeometric characterization, J. Archaeol. Sci.: Rep. 8 (2016) 434–443, https:// doi.org/10.1016/j.jasrep.2016.06.051. [21] L.F. Vieira Ferreira, A. Gonzalez, M.F.C. Pereira, L.F. Santos, T.M. Casimiro, D.P. Ferreira, D.S. Conceição, I. Ferreira Machado, Spectroscopy of 16th century Portuguese tin-glazed earthenware produced in the region of Lisbon, Ceram. Int. 41 (2015) 13433–13446, https://doi.org/10.1016/j.ceramint.2015.07.132. [22] L.F. Vieira Ferreira, I. Ferreira Machado, M.F.C. Pereira, T.M. Casimiro, Portuguese Blue-on-Blue 16th-17th c, Pottery. Archaeometry 60 (2018) 695–712, https://doi. org/10.1111/arcm.12336. [23] L.F. Vieira Ferreira, M. Varela Gomes, M.F.C. Pereira, L.F. Santos, I. Ferreira Machado, A multi-technique study for the spectroscopic characterization of the ceramics from Santa Maria do Castelo church (Torres Novas, Portugal), J. Archaeol. Sci.Rep. 6 (2016) 183–189, https://doi.org/10.1016/j.jasrep.2016.02.013. [24] L.F. Vieira Ferreira, I. Ferreira Machado, A. Gonzalez, M.F.C. Pereira, T.M. Casimiro, A new fifteenth-to-sixteenth-century pottery kiln on the Tagus basin, Portugal, Appl. Phys. A 124 (2018) 770–782, https://doi.org/10.1007/s00339-0182197-x. [25] L.F. Vieira Ferreira, D.S. Conceição, D.P. Ferreira, L.F. Santos, M.F.C. Pereira, T.M. Casimiro, I. Ferreira Machado, Portuguese tin-glazed earthenware from the 17th century. Part 2: a spectroscopic characterization of pigments, glazes and pastes of the three main production centers, Spectrochim. Acta, Part A 149 (2015) 285–294, https://doi.org/10.1016/j.saa.2015.04.090. [26] L.F. Vieira Ferreira, I.L. Ferreira Machado, Surface Photochemistry: organic molecules within nanocavities of Calixarenes, Curr. Drug Discov. Technol. 4 (2007) 229–245. [27] RRUFF Project Database, accessed in February 2019. [28] P. Ballirano, C. De Vito, L. Medeghini, S. Mignardi, V. Ferrini, P. Matthia, D. Bersani, P.P. Lottici, A combined use of optical microscopy, X-ray powder diffraction and micro-Raman spectroscopy for the characterization of ancient ceramic from Ebla (Syria), Ceram. Int. 40 (2014) 409–419. [29] D. Bersani, P.P. Lottici, Raman spectroscopy of minerals and mineral pigments in archaeometry, J. Raman Spectrosc. 47 (2016) 499–530, https://doi.org/10.1002/
8