The retrieval of some unusual buried treasure in Lake Titicaca uncovered two small offerings in a carved stone box in the form of a gold foil object and a llama made of shell. Published in the journal Antiquity, the discovery reveals that the valuable materials contained within the box were most likely an offering given as part of an Inca ritual, similar to those found at the sites of human sacrifice.
The llama is carved from a spondylus shell, a group of spiny oysters with spiky shells, which had long been an object of long-distance trade even before the Inca period. As Christophe Delaere, a junior research fellow from the Université libre de Bruxelles, Belgium, explained in an email to IFLScience, spondylus was a rare material that was considered all the more valuable if it was transformed into an object, such as the llama, as this was strictly controlled by the Inca elite making it a worthy offering for rituals and ceremonies.
The llama was recovered by divers who retrieved the sealed stone box from the lake’s bed and was largely still intact although currents had eroded one side. Inside, beneath a layer of silt that had filtered in the ancient container, was the llama and a roll of gold foil. Similar stone boxes have been found before but most hadn't remained sealed and were found empty, making this treasure chest a particularly exciting find. So why did this one remain closed? "There are two reasons for this," Delaere told IFLScience. "The K'akaya site has never been looted, and the K'akaya site suffers much less from the lake's weather. All the conditions were present at K'akaya to find the offering intact."
"The cap was tightly sealed but it was not water-tight so when we discovered the box, Christophe and I had to actually micro-excavate it until we found the two miniature offerings," said José M. Capriles, assistant professor of anthropology at Penn State, US, in an email to IFLScience. "Within the accumulated sediment there were even tiny fish bones suggesting small organisms did get inside. The preservation of both materials however is outstanding because both gold and shell (calcium carbonate) do not corrode or decompose under water."
The llama, found on Lake Titicaca’s K'akaya reef, joins a mounting body of evidence that South America’s largest lake was a focus of ceremony for the Inca. In 1977, some broken objects believed to be part of offering bundles were dredged up near the Island of the Sun by amateur divers. Then in 1988 and 1992, professional divers excavated the Khoa reef and found similar Inca stone boxes containing small figures. Further objects have been discovered both on land and in water in other parts of what used to be the Inca Empire, but the researchers believe Lake Titicaca was of particular significance to the empire.
"One of the goals of our underwater archaeological survey was to identify the existence of similar sites and to our surprise we found at least one," said Delaere. "It presents not only one of the rare intact discoveries of an Inca underwater offering, but also that it was found at another place in the lake, which has an important implication for understanding the relationship between the expanding Inca empire, the local communities who lived in the lake, and Lake Titicaca itself prior to European contact.
"The inland underwater world remains largely unexplored and offers outstanding opportunities to understand prehistoric societies. The underwater heritage of Lake Titicaca still has many surprises to reveal."