Navigation – Plan du site

AccueilNuméros104I - Technologies, héritages et mo...Lead pollution in the ancient har...

I - Technologies, héritages et mobilités à l’échelle des bassins portuaires

Lead pollution in the ancient harbours of Marseilles

Contamination au plomb dans les ports antiques de Marseille
Gaël Le Roux, Alain Véron et Christophe Morhange
p. 31-35

Résumés

La concentration et la composition isotopique du plomb ont été mesurées dans deux coupes stratigraphiques provenant du port antique de Marseille. Les sédiments datés de la période romaine montrent une augmentation de la concentration en Pb et un changement dans les rapports isotopiques. Ces variations traduisent indiscutablement une pollution au Pb dans le port romain de Marseille. La composition isotopique du plomb permet de retracer l´origine du métal utilisé à cette période, probablement un mélange provenant de mines françaises et espagnoles.

Haut de page

Entrées d’index

Géographique :

France, Marseille
Haut de page

Texte intégral

Introduction

1Lead (Pb) is a toxic metal dispersed in the environment by ancient and modern human activities such as mining, metallurgy, fossil energy burning or waste incineration (Nriagu, 1998; Shotyk & Le Roux, in press). However anthropogenic Pb was already emitted since the beginning of the metallurgy (Nriagu, 1983). Regional and global atmospheric pollution by ancient mining and smelting was already highlighted by increase in Pb concentration and shift in Pb isotopes recorded in peat bogs, lakes and ice cores (Brännvall et al., 1999; Le Roux et al., 2004; Rosman et al., 1997; Weiss et al., 1999). Little research (Labonne et al., 1998; Le Roux et al., 2003) has been done on local contaminations near ancient urban coastal centres.

2In the present study, we investigate coastal sediments from the ancient harbour of Marseilles. Our objectives are to: (i) distinguish between natural and anthropogenic Pb in the sediment using Pb concentration and Pb isotopes and therefore evidence possible Pb emissions during ancient times; (ii) to estimate the general chronology of anthropogenic Pb input in the harbour and (iii) using the isotopic composition of Pb, to trace the sources of Pb in the ancient harbour of Marseilles.

1. Material & methods

1.1. Site

3Briefly, the ancient harbour of Marseilles is located in the centre of the actual French Mediterranean town of Marseilles. Marseilles was founded ca. 600 BC by the Phoceans; it was the first Greek colony in France. The site had been earlier occupied before as testified by a shelly deposit and by the scattered prehistoric discoveries around the Ancient Harbour (Morhange et al., 1996). A bracelet dated from the end of the 7th century BC and beginning of the 6th century BC seems to attest a continuous occupation until the arrival of Greeks (Hesnard et al., 1999).

Fig. 1 - Sedimentological and chemical profiles of the 2 sections collected in the ancient harbour of Marseilles

Fig. 1 - Sedimentological and chemical profiles of the 2 sections collected in the ancient harbour of Marseilles

In the middle of the figure, sketch showing the summarized stratigraphy of the harbour (Morhange et al., 2001) and the location of the cores.

4The Phoceans installed in naturally sheltered creek called Lacydon a significant port located between Spain and Aegean Area. It was a military and trading port as attested by ceramics and amphorae coming from Greece but also from other areas like Etrury or Phoenicians colonies (Hesnard et al., 1999).

5The presence of shipbuilding yards and metallurgical activities (including monetary) is attested around the harbour at the Hellenistic Time (Hermary et al., 1999; Hesnard et al., 1999). At the Roman Period (1st century BC- end of the 4th century AD), Marseilles preserved its commercial role and urbanization increased (Hesnard et al., 1999). For more details about the site and the impacts of the development of the harbour, the reader could refer to Morhange et al. (2001).

1.2. Material

6The sediments come from 2 sections F fig. 1). One profile, age dated by 14C, comes from the Bargemon excavation and covers 5000 years of sediment deposition. The other one come from J. Verne excavation and is dated to the Roman Period (1st century AD) as attested by archaeological artefacts.

7Sub-samples of samples stored in frozen were taken after decontamination by cutting the outside edges. They were freeze-dried and hand-powdered in an agate mortar.

1.3. Methods

850-70 mg of sediments were digested at 120°C with an HNO3-HCl-HF mixture in acid pre-cleaned Teflon Beakers. After evaporation, aliquots were dissolved in an HBr (0.5 N) solution. Lead was separated using Agl-X8 resin (50µl). Isotope ratios (204Pb, 206Pb, 207Pb, 208Pb) were determined by standard thermal ionisation mass spectrometry (Hamelin et al., 1990) on a Finnigan MAT 262 at CEREGE, Aix-en-Provence. Mass fractionation was corrected using NBS SRM 981. Pb concentrations were measured by isotopic dilution method using a 208Pb spike solution. Quality of the results were controlled by analysis of the soil standard RTC S 408 (certified value: 95.3 ± 12.4 µg g-1; measured value: 107 ± 1µg g-1). For background knowledge about Pb and Pb isotopes, the reader could refer to Shotyk and Le Roux (in press) and Dickin (1995). About the use of Pb isotopes in archaeology, the reader could refer, for example, to Gale and Stos-Gale (1982), Hosler and Mac Farlane (1996) and to the book of Lambert (1997).

2. Results

  • Pre-Greeks sediments (before 600 BC), Bargemon Excavation (Fig. 1 bottom)Pb concentrations are under 15 µg g-1 and the isotopic composition does not vary and is around 1.2 for 206Pb/207Pb.

  • Greek sediments, Bargemon excavation (Fig.1 bottom)
    There is a small increase of the Pb concentrations above -2.5m despite 2 samples with very low concentrations. This trend is not correlated with a variation of the Pb isotopic composition or with the mineralogy. These sediments are dated from the Archaic Period and unfortunately, we did not sample sediments from the Hellenistic Period.

  • Roman sediments, J. Verne excavation (Fig. 1 top)

  • The base of the «Roman» clays (samples D1, D2, D3) has very low Pb concentration (4- 9 µg g-1) and the isotopic ratios are similar to those found in the Greek clays (206Pb/207Pb > 1.200). One possibility is that dredging operations reworked older sediments.

  • At the top (D5, D6), Pb concentrations are more than 10 times higher (100-300 µg g-1) than in the bottom clays and 206Pb/207Pb decreases (206Pb/207Pb < 1.183). The sample D4 (206Pb/207Pb=1.198) is intermediate considering only the isotopic signature.

3. Discussion

3.1. Evidences of anthropogenic Pb in the sediments of Marseilles harbour

9Pb isotopic composition for natural sediments is different from the composition of Pb-Cu-Ag ores (Fig. 2). The shift in the isotopic composition of the top sediments of the J.Verne site is a clear evidence of anthropogenic Pb for the period from 0 to 200 AD (= US 195 Jv 10). Moreover the high concentrations of Pb for the samples D5 and D6 could be interpreted as a large pollution event comparable with pollutions in modern harbours (Le Roux, 2001). Assuming that the natural contribution of Pb to the harbour was constant, more than 90% of Pb for the samples D5 and D6 was of anthropogenic origin. This is in good agreement with previous study that shows Pb pollution during the Roman Period.

Fig. 2 - 206pb/207pb vs. 208pb/206pb diagram for sediments samples

Fig. 2 - 206pb/207pb vs. 208pb/206pb diagram for sediments samples

Metallic artefacts (Labonne et al., 1998; Trincherini et al., 2001), Véron (unpublished data), different mining areas (Rohl, 1996; Stos-Gale et al., 1995) and natural Pb (Shotyk, 2001; Sun, 1980).

10The other sediments do not show such a large increase in Pb concentration or a shift in Pb isotopic composition. The isotopic composition in the sediments is typical of natural sediments (Fig. 2) and does no alone show any evidence of Pb contamination. However it could not be excluded that there was Pb contamination in the harbour during the early Greek occupation or even earlier. Indeed there is a small increase of the Pb concentration during the Greek Period. Moreover some Pb ores in Greece have an isotopic composition close to the natural signature of the sediments and therefore it could not be excluded that there was a small contamination not distinguishable with the isotopic composition and only marked by a small increase in concentration. More analyses like Cu or Ag measurements would be required to detect any trace of metal contamination.

3.2. Tracing Pb sources of the Roman contamination

11On the Figure 2, are plotted different isotopic signatures of Pb-Cu-Ag ores, roman artefacts found in the Southern part of France and the samples. The polluted Roman samples are not corresponding to a precise isotopic field but more to a mixing line between different ores, for example from French and Spanish mines. Indeed, mixture of different ores because of recycling for example was common in the Roman Empire. Assuming a mixture of two sources and that one source of Pb has the signature of artefacts found in the Mediterranean French Area (corresponding more or less to mines from Massif Central), we can deduce that the second source is the SE Spanish mines and not the British mines. This is a reasonable hypothesis as Spain was the most important producer during the Roman Period (Nriagu, 1983). However a more complicated system with more than 2 sources could not be excluded and again multi-tracer analysis (Cu, Ag, Sb) will refine our analyses.

Conclusions

12Pb concentrations and Pb isotopes measurements were done in sediments from the Ancient Harbour of Marseilles. Whereas no large change in the Pb chemistry occurred with the foundation of the harbour at the Archaic Period (6th-5th century BC), sediments from the Roman Period are polluted as evidenced by higher Pb concentrations and shift in Pb isotopic composition. This pollution has not a clear source and it was probably a mixing of different Pb ores from Spain and France. Measurements of other metals used in the Antiquity like copper and silver will permit to better characterize the history of metallurgical activities.

Haut de page

Bibliographie

Brännvall M.-L., Bindler R., Renberg I., Emteryd O., Bartnicki J. and Billström K., (1999), The Medieval Metal Industry was the cradle of modern large-scale atmospheric lead pollution in northern Europe, Environmental Science and Technology 33(24), p.4391-4395.

Dickin A. P., (1995), Radiogenic isotope geology, Cambridge University Press, 490 p.

Gale N. H. and Stos-Gale Z. A., (1982), Bronze Age Copper Sources in the Mediterranean: A New Approach, Science 216 (4541), p.11-19.

Hamelin B., Grousset F. and Sholkovitz E. R., (1990), Pb isotopes in superficial pelagic sediments from the North Atlantic, Geochimica et Cosmochimica Acta, 54, p.37-47.

Hermary A., Hesnard A. and Treziny H., (1999), Marseille grecque, 600-49 av. J.-C., la cité phocéenne, Errance, 184 p.

Hesnard A., Moliner M., Conche F. and Bouiron M., (1999), Marseille: 10 ans d’archéologie, 2600 ans d’histoire, Musées de Marseille/Edisud, 183 p.

Hosler D. and MacFarlane A., (1996), Copper sources, metal production, and metals trade in late postclassic Mesoamerica, Science(273), p.1819-1824.

Labonne M., Ben Othman D. and Jean-Marck L., (1998), Recent and past anthropogenic impact on a Mediterranean lagoon: Lead isotope constraints from mussel shells, Applied Geochemistry 13(7), p.885-892.

Lambert J. B., (1997), Traces of the Past: unraveling the secrets of archaeology through chemistry, Addison-Wesley, 319 p.

Le Roux G., (2001), Caractérisation Géochimique de l´Anthropisation dans les Ports Antiques Méditerranéens, Master Thesis, University of Aix-Marseille 1, 29 p. + ann.

Le Roux G., Véron A. and Morhange C., (2003), Geochemical evidences of early anthropogenic activity in harbour sediments from Sidon, Archaeology & History in Lebanon (Autumn 2003), p.115-119.

Le Roux G., Weiss D., Grattan J. P., Givelet N., Krachler M., Cheburkin A. K., Rausch N., Kober B. and Shotyk W., (2004), Identifying the sources and timing of ancient and medieval atmospheric lead pollution in England using a peat profile from Lindow bog, Manchester, Journal of Environmental Monitoring 6, p.502-510.

Morhange C., Laborel J. and Hesnard A., (2001), Changes of relative sea level during the past 5000 years in the ancient harbor of Marseilles, Southern France, Palaeogeography, Paleoclimatology, Palaeoecology, 166, p.319-329.

Morhange C., Provansal M., Hesnard A., Bouiron M., Bourcier M., Carbonel P. and Weydert P., (1996), Morphogénèse et impacts anthropiques sur les rives du Lacydon à Marseille (6000 av. J.C -500 ap. J.-C.), Annales de géographie (587), p.32-46.

Nriagu J. O., (1983), Lead and Lead Poisoning in Antiquity, New-York, 434 p.

Nriagu J. O., (1998), Tales Told in Lead. Science 281, p.1622-1623.

Rohl B. M., (1996), Lead isotope data from the isotrace laboratory, Oxford: Archaeometry data base 2, galena from Britain and Ireland, Archaeometry 38(1), p.165-180.

Rosman K. J. R., Chisholm W., Hong S., Candelone J.-P. and Boutron C. F., (1997), Lead from Carthaginian and Roman Spanish Mines Isotopically Identified in Greenland Ice Dated from 600 BC to 300 AD, Environmental Science and Technology 31(12), p.3413-3416.

Shotyk W., (2001), Geochemistry of the peat bog at Etang de la Gruère, Jura Mountains, Switzerland, and its record of atmospheric Pb and lithogenic trace metals (Sc, Ti, Y, Zr, and REE) since 12,370 14C BP, Geochimica et Cosmochimica Acta 65 (14), p.2337-2360.

Shotyk W. and Le Roux G., (in press), Biogeochemistry and Cycling of Lead, in Biogeochemical Cycles of the elements, Vol. 43 (A. Sigel, H. Sigel, and R.K.O. Sigel, ed.), M.Dekker.

Stos-Gale Z. A., Gale N. H., Houghton J.,and Speakman R., (1995), Lead isotope data from the isotrace laboratory, Oxford: Archeometry data base 1, ores from the western Mediterranean, Archaeometry 37(2), p.407-415.

Sun S. S., (1980), Lead isotopic study of young volcanic rocks from mid-ocean ridges, ocean islands and islands arcs, Phil.Trans.R.Soc.Lond. A 297, p.409-445.

Trincherini P. R., Barbero P., Quarati P., Domergue C. and Long L., (2001), Where do the lead lingots of the Saintes-Maries-De-La-Mer wreck come from? Archeology compared with physics, Archaeometry 43(3), p.393-406.

Weiss D., Shotyk W. and Kempf O., (1999), Archives of Atmospheric Lead Pollution, Naturwissenschaften(86), p.262-275.

Haut de page

Table des illustrations

Titre Fig. 1 - Sedimentological and chemical profiles of the 2 sections collected in the ancient harbour of Marseilles
Légende In the middle of the figure, sketch showing the summarized stratigraphy of the harbour (Morhange et al., 2001) and the location of the cores.
URL http://journals.openedition.org/mediterranee/docannexe/image/2072/img-1.jpg
Fichier image/jpeg, 312k
Titre Fig. 2 - 206pb/207pb vs. 208pb/206pb diagram for sediments samples
Légende Metallic artefacts (Labonne et al., 1998; Trincherini et al., 2001), Véron (unpublished data), different mining areas (Rohl, 1996; Stos-Gale et al., 1995) and natural Pb (Shotyk, 2001; Sun, 1980).
URL http://journals.openedition.org/mediterranee/docannexe/image/2072/img-2.jpg
Fichier image/jpeg, 198k
Haut de page

Pour citer cet article

Référence papier

Gaël Le Roux, Alain Véron et Christophe Morhange, « Lead pollution in the ancient harbours of Marseilles »Méditerranée, 104 | 2005, 31-35.

Référence électronique

Gaël Le Roux, Alain Véron et Christophe Morhange, « Lead pollution in the ancient harbours of Marseilles »Méditerranée [En ligne], 104 | 2005, mis en ligne le 28 janvier 2009, consulté le 28 mars 2024. URL : http://journals.openedition.org/mediterranee/2072 ; DOI : https://doi.org/10.4000/mediterranee.2072

Haut de page

Auteurs

Gaël Le Roux

Laboratory of geochronoly, Institute of Environmental Geochemistry, University of Heidelberg, Germany

Alain Véron

CEREGE, UMR CNRS6635, Université Aix-Marseille, Aix en Provence, France

Christophe Morhange

CEREGE, UMR CNRS6635, Université Aix-Marseille, Aix en Provence, France

Articles du même auteur

Haut de page

Droits d’auteur

Le texte et les autres éléments (illustrations, fichiers annexes importés), sont « Tous droits réservés », sauf mention contraire.

Haut de page
Rechercher dans OpenEdition Search

Vous allez être redirigé vers OpenEdition Search