Metallurgy pollution in the north of the peninsula began 5,000 years ago – lagranepoca

View of the bog of La Molina, which has carried out the study. / Venasalas.com

A study by the University of Santiago de Compostela shows signs of metal contamination in the north of the Iberian Peninsula date back to the Copper Age, and are the oldest found in that territory.

Air pollution by metals in the north of the Iberian Peninsula began 1500 years earlier than previously thought, that is, approximately between eleven and sixteen centuries earlier than indicated so far the research in this area and about 1,100 years earlier than it agreed to the south. This is the main finding of a paper published in the journal Science of the Total Environment by researchers at the University of Santiago de Compostela (USC).

The new results achieved in collaboration with researchers from Swedish universities Stockholm and Umea and British Brunel and Aberdeen “shed light on the debate over the timing of the introduction of mining and metallurgy, the beginning until now was considered to take place in the south of the peninsula, by the influence of the peoples living on the shores of the Mediterranean, “says Professor of Soil Science and Agricultural Chemistry of the USC and coordinator of the group, Antonio Martinez Cortizas.

The metal composition of the substrates identified in the bog of La Molina “seem to indicate a connection between the metallurgy of northern Spain and other areas of Europe, particularly in the south of France,” the researcher from USC, for whom the evidence of air pollution show that the north “was not as backward as it was believed, in the introduction of the ‘new technologies’ in prehistoric times, but quite the opposite. “

Peatlands, books environmental record

This new chronology pointed to by researchers at USC was possible thanks to a line of work which the group in the bog of La Molina (Asturias) to rebuild the environmental impact of human activities during the recent prehistory.

According to Antonio Martinez Cortizas peatlands are “ideal sensors for air pollution and deposition of metals and other substances are produced directly from the atmosphere.”

various human activities such as mining and metallurgy The burning of fossil fuels (particularly gasoline) or incineration of waste emitted into the atmosphere trace metals, once issued, are transported and deposited in soils and waters, and may go to the food chain.

Due to the continuous accumulation of plant debris, peat bogs are digging into ever deeper layers of the elements accumulated in a given period.

This enables the analysis of testimonies of peat, supported by precise chronology allows reconstructing the composition of the atmosphere in the past. It is information that scientists consider “especially important” in the case of pollutants by the lack of systematic studies that date back more than a few years or decades.

In this regard, an important point New research is “confirmation that the use of metals has left a recognizable landmark in the environment from the very beginning of metallurgy”.

The team used the isotopic composition of lead content of various metals (chromium, zinc and lead, among others) in peat as indicators to reconstruct the intensity of pollution over time.

As Cortizas Martinez added, the phases are displayed by the register a true reflection of the known cultural periods 5,000 and 2,000 years ago: the Chalcolithic, Bronze Age and Iron Age. According to the analyzes, the phase of intense prehistoric pollution would be located in the Late Bronze Age (between 3,500 and 2,800 years).

Geochemistry and history

The results are “a great interdisciplinary relevance” says Antonio Martinez Cortizas. In this sense, the geochemical studies stand as a complementary tool to describe the history of human activities and their impact on the environment, “using this alternative peatlands as books that read that part of history that has not been conserved in other files “.

For example, the researcher points out that the records studied show that mining activities probably took place in the immediate environment of the bog, within a few tens of kilometers “Although at present there is no trace of prehistoric mining.”

In line with the proposal in some archaeological research, the researchers suggest that continued use of mines to over time, and particularly in Roman times, “would have caused the loss of the records of prehistoric mining.”

Original article here