New excavations in Easter Island’s statue quarry: Soil fertility, site formation and chronology
by Jo Anne van Tilburg
A recent study has demonstrated that the work done in the quarry at Rano Raraku, where some thousand moai (statues) were carved from the years 1455-1605 AD, had also enriched the soil with phosphorus and other minerals, improving the conditions for cultivating domestic plants, such as the sweet potato, taro, manioc, gourds, mahute (paper mulberry), bananas and other food species.
Rano Raraku: Much More Than a Quarry
Rano Raraku, the quarry of the moai, covers 126,741 m2 (31.3 acres) and is the site of production of the greatest amount of the stone statues known as moai. It contains 809 archaeological remains. Of these, only 59.7% are moai; the rest is made up of foundations of houses (hare vaka), cooking areas (umu pae), petroglyphs and structures of rock gardens. “This tells us that in this place there were habitations, tools were produced, plants were raised and ceremonies, including funerals, were held,” indicates the archaeologist Jo Anne van Tilburg, who, in 2010, with students and members of the Rapanui community, began the Easter Island Project (EISP), a program of archaeological research in the crater of Rano Raraku.
Within the excavations, a completely new sculpture was discovered at five meters (16.5 feet) depth (moai RR-0001-156) on the interior slope of Rano Raraku. According to Van Tilburg, this statue was erected in a deep hole on a papa, a solid stone base, and held in place by a large stone of a meter (slightly over one yard) in height. This corresponds to the system of engineering utilized by the ancient sculptors when they placed a statue in its definitive location. In addition, they found firm evidence that another, older quarry lay underneath this bedrock. This discards previous theories that all the statues on the slopes of Rano Raraku were raised in order to later finish them and move them away.
The paradigm was altered when it was determined that these statues were found there because the quarry at Rano Raraku was an important sacred site and not just a place for the production of statues.
The Quarry’s Soil: A Sacred Garden
“All the plants with domestic use were introduced by the Polynesian settlers, which implied the transport and adaptation of tropical species to a small, isolated island with a sub-tropical climate. We don’t know how long it took with this process of colonization to be able to maintain a highly hierarchical society with chiefs, priests and a variety of specialists with an intensive agriculture based on tubers,” explains José Miguel Ramirez-Aliaga of the Universidad de Playa Ancha in Valparaiso, who formed part of an international team led by Sara Sherwood of the Department of Earth and Environmental Systems at Sewanee: The University of the South (Tennessee) and which found a horticultural site on the southern and eastern interior slopes of Rano Raraku, which functioned from the XIVth Century until the early XIXth Century.
“During this period of socio-political transformation and of changes in the use of the land throughout the Island, vegetable plots were developed in rock gardens, a technique which required an intense use of manual labor to increase productivity while the fertility of the soil diminished within a period of deforestation,” states the study.
This study reaffirms Rano Raraku as the principal center for production of moai, establishing chronological parameters for the statue RR-0001-156 and describes the agricultural fertility, offering a hypothesis of a rich scenery and multiple uses of the interior slopes of the quarry which have no parallel in other places on Rapa Nui.
What Does This Discovery Mean for Understanding Rapa Nui?
The image of Rano Raraku as a mere sculpting workshop is definitively discarded. The quarry was simultaneously a production center, a dwelling site, an agricultural garden and a sacred place where ceremonies were held. This finding reinforces what the complete visitor guide to Rano Raraku already outlines about the complexity of this volcano: the freshwater lake inside the crater was not a secondary detail but part of an intentional ecosystem managed by the Rapanui for centuries.
Soon to be published is a new study on the meaning of the complex petroglyphs found on the two moai recently excavated at the quarry of Rano Raraku and those which are on the moai Hoa Hakananai’a, the sacred guardian from Orongo who has been the subject of repatriation talks with the British Museum since 2019.
Frequently Asked Questions about the Rano Raraku Excavations
What did the EISP discover at Rano Raraku?
The Easter Island Statue Project (EISP), led by archaeologist Jo Anne van Tilburg, discovered that Rano Raraku was not only a moai quarry but also a sacred site with dwellings, horticultural gardens and ceremonial areas. A new moai (RR-0001-156) was found at five meters (16.5 feet) depth, and evidence of an even older quarry was found below the bedrock.
How many statues are at Rano Raraku?
Rano Raraku contains 809 archaeological remains. Only 59.7% of these are moai; the rest consists of house foundations, cooking areas, petroglyphs and rock gardens. The newly discovered moai RR-0001-156 was found at five meters depth on the interior slope of the crater.
Why are the moai at Rano Raraku buried?
The moai on the slopes of Rano Raraku are not just heads — they have complete bodies buried underground. The EISP study determined that some of these statues were not there temporarily waiting to be transported but were permanently erected at the sacred site, placed in deep holes on a solid stone base (papa), following the same engineering system used at the ceremonial platforms (ahu) across the island.
What is the EISP?
The Easter Island Statue Project (EISP) is an archaeological research programme begun in 2010 by archaeologist Jo Anne van Tilburg, together with students and members of the Rapanui community. Its aim is to systematically document and excavate the moai of the Rano Raraku crater, generating the first complete scientific inventory of the site.
