Early metal pollution in southwestern Europe: the former littoral lagoon of El Almarjal (Cartagena mining district, S.E. Spain).A sedimentary archive more than 8000 years old

Abstract

A borehole drilling campaign has allowed the study of a former littoral lagoon located next to the harbour city of Cartagena in South-East Spain (close to the Sierra de Cartagena polymetallic ore deposits). This lagoon, which developed during the Holocene, was first a shallow sedimentary marine environment and later evolved into a swampy semi-endorheic basin named "Almarjal" (after the Arab term from the fourteenth century). The lagoon eventually dried out and at present forms part of the substratum of the modern sector of the city urban area. The basin representative sediments are sapropelic black silty facies forming a continuous sedimentary archive, accounting for more than 8000 years of depositional phenomena. The geochemical study of these sediments, together with their absolute calibrated dating by C, allows definition of successive stages of mining and metallurgical activities in the area. In turn, this information provides a more comprehensive perspective regarding metal pollution, particularly lead contamination during different periods of the Recent Prehistory and the Classical Age. The results indicate that the beginning of contamination by lead and other heavy metals occurred as early as 4500 years ago, when the Final Chalcolithic period was taking place in the South-East of the Iberian Peninsula. This finding provides further insights regarding the debate on the origins of lead mining and metallurgy in SE Spain.

Middle and Late Holocene vegetation history of the Murcia region from a new high-resolution pollen sequence from the Mar Menor lagoon

“…Finally, the lead concentration in lagoon sediments increased for the very first time in the sequence at the end of Late Argar around 1500-1400 BC (Figure 5). This lead pollution strongly supports the presumptions of mining and metallurgical activities suggested by the archaeological corpus for this period (Eiroa 2004) and is consistent with previous studies on lead pollution in this area (Manteca et al 2017). Figure 5 Figure 5 (color): Comparison of Mar Menor pollen data with lead concentration in MM2 core (Dezileau et al in prep), and with pollen and microcharcoal data from the Baza sequence (Carrión et al 2007) for the Argar period.…”

Comment on “Next‐Generation Ice Core Technology Reveals True Minimum Natural Levels of Lead (Pb) in the Atmosphere: Insights From the Black Death” by More et al.

“…The period of the Black Death is certainly the lowest point in this one ice record, but more than four decades of research involving analyses of lake‐sediment, marine‐sediment, and peat records from many sites across Western Europe has already established not only that human activities have contributed to atmospheric Pb pollution uninterruptedly over the past 2,000 years, but that it is necessary to go back 2,500 or even 3,500 years in order to establish background, prepollution conditions (Figures b–f), which is beyond the 2,000‐year time frame of the ice record. These studies have included sites in, for example, England, Switzerland, Sweden, Spain, France, Germany, Scotland, and Austria (Bindler et al, ; Brännvall et al, , ; Breitenlechner et al, ; Cloy et al, ; Elbaz‐Poulichet et al, ; Forel et al, ; Garcia‐Alix et al, ; Jouffroy‐Bapicot et al, ; Klaminder et al, ; Küttner et al, ; Kylander et al, ; Le Roux et al, , ; Leblanc et al, ; Lee & Tallis, ; Manteca et al, ; Martínez‐Cortizas et al, , ; Mil‐Homens et al, ; Shotyk et al, ; Thevenon et al, ). This research in turn rests on the exploratory work by Clair Patterson and coworkers during the 1960–1980s of the historical dimensions of metal production (Murozumi et al, ; Patterson, , , ; Settle & Patterson, ).…”

Proyecto “Arqueometalurgia de la Península Ibérica” (1982-2017)

“…Estos cambios de escala productiva propuestos a través de los cambios en la tecnología metalúrgica están siendo confirmados por los estudios de contaminación ambiental, cada vez más frecuentes (Leblanc et al 2000;García Alix et al 2013;Martínez Cortizas et al 2016;Manteca et al 2017). Vistos en su conjunto muestran, con las debidas variaciones regionales vinculadas a la mayor o menor intensidad de las explotaciones mineras y del metal extraído (Pb o Cu), que en el Calcolítico (hacia el 4500 cal BP) se detectan los primeros indicios de actividad metalúrgica, pero siempre a un nivel reducido.…”