Perou: Archaeology: Of Ice and Hair and Drones

Corey Watts

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Delve into the rocky history of Peru with this twenty-first century take.

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(Photo: Elsa Tomasto Cagigao, Journal of Archaeological Science, March 2015)

Spend even a few days in Peru and you can’t but help feel the history of the place veritably poking out of the landscape around you. Even amidst the restaurants, traffic, and souvenir shops of Miraflores the edifice of Huaca Pucllana rises as a constant reminder of a successful civilization before this one.

History at your fingertips and everywhere the land bears the hallmarks of humanity in close concert with nature.

On a recent hike through the foggy Andes just east of Lima, I was once again reminded of just how present the past is in many parts of Peru. In amongst terraced fields lie the ruins of a pre-Inca society: walls, tombs, and lookouts lie along the winding mountain track.

In his 2005 book 1491: New Revelations of the Americas Before Columbus, award-winning journalist and author Charles C. Mann illuminates a peopled continent. Prior to the 16th century, the Americas may have carried as many as 100 million people. They practised a sophisticated agriculture, built great metropolises, and reworked the country in incredible feats of civil engineering. Contact with the Old World saw scores of millions perish from disease, and their farms and settlements abandoned and overgrown.

In the last month, three new studies are revealing not just stone relics, but something about how people lived, what they ate, and how they changed the world around them. Today’s archaeologists are adding to their traditional toolkit of trowel and brush with some highly sophisticated technologies and scientific techniques.


For instance, a joint US–Peruvian archaeological team, including Elsa Tomasto Cagigao of the Pontifical Catholic University in Lima, has analysed samples of hair obtained from 14 mummified people. The mummies were obtained from the necropolis of Paracas, which dates back 2,000 years. First excavated by the famous Peruvian archaeologist Julio C. Tello in 1925, the site’s artefacts—clothes, tools, etc. — have been the subject of much study in subsequent decades. But this is the first time scientists have delved into the very molecular make-up of the Paracas people to reveal what they ate and something about how they lived.

Hair is surprisingly long-lasting and easy for archaeologists to find. Several studies have already shown how the hair of ancient Andean peoples retains chemical markers of their exposure to poisons like arsenic, and drugs such as coca and nicotine. Even stress leaves telltale signs.

What is exciting to me about this research is that we are using new scientific techniques to learn more about mummies that were excavated almost 100 years ago,” says Kelly Knudson, lead researcher and Associate Professor from Arizona State University.

It seems that, during their last months, these people ate a good deal of seafood, as well as maize and beans — not too different to today’s Peruvian cuisine. Their diet also reveals that they may have travelled back and forth from the highlands to the coast. It is, as Knudson says, a “very intimate look at the past.”

Of course, with the arrival of Francisco Pizarro in the early 16th century almost everything about the lives of the people and their environment changed.

Silver-lined glaciers

In a paper published in the prestigious journal Proceedings of the National Academy of Sciences, US and Danish scientists report how they have tapped into high-altitude glaciers to unlock the environmental history of the Andes.

Before the Conquest, the Inca already knew how to refine silver but annexation by the Spanish Empire saw production rise several-fold as thousands of indigenous people were put to work in mines. Importantly, the Spaniards introduced new technologies: smelting silver ore with lead and amalgamating the precious metal with mercury.

Growing clouds of metallic dust spewed out of Spanish foundries in what is today Bolivia, drifted over the Andes, and landed on glaciers in Peru. Over the years, the dust particles became trapped beneath layer upon layer of ice and snow, leaving an indelible log of the past. Almost 250 years before the Industrial Revolution in Europe the air of the Andes was being polluted for profit. Even so, this is nothing compared to the levels of atmospheric pollution reached in Peru during the 20th century—the highest yet seen in the frozen record of the development of the region.

Drones over the Amazon

From icy mountaintops to the steamy rainforest of the Amazon, new technologies may be about to revolutionize our view of that vast, mega-diverse environment.

Traditionally, the forest has been viewed as pristine wilderness or at least largely bereft of human interference—before the mining and logging of the modern era, that is. Increasingly, however, archaeologists are finding evidence human handiwork: aerial reconnaissance has shown what appear to be the outlines of antique earthworks in the forest, together with patches of so-called terra preta, or ‘black earth’, which was used by indigenous farmers to enrich soil. Artefacts like these suggest that large chunks of the forest may have been reworked for large-scale agricultural settlements for centuries before Columbus set sail. The extent of this human presence is still hotly debated, however.

Now, Uruguayan archaeologist José Iriarte, based at the University of Exeter in the United Kingdom, plans to use drones in the hope of finding evidence that may settle the debate. Archaeologists have already used satellites and aircraft to spot artefacts such as buildings and burial mounds, underwater and underground. Compared to spacecraft and aeroplanes, however, drones are inexpensive. Using remote-sensing technology, Iriarte’s project could lift the thick green veil of the forest canopy to reveal patterns in soil and vegetation that are the signs of a civilization long since overgrown.

Is the very biodiversity of the forest—the wildlife now threatened by development and climate change—a human artefact? The new technologies may be about to tell us.

Science is building a bridge between the lives and landscape of the past; offering Peruvians and the world a richer understanding of the country’s heritage, and perhaps lessons for the future stewardship of the land.