A joint Belgian-Chilean biological mission, conceived and headed by Prof. H. Dumont of the Department of Morphology, Systematics and Ecology of the Gent University, spent about five weeks on Easter Island in August and September 1990. The project was undertaken specifically to obtain a reasonably complete picture of the palaeoenvironmental evolution of the region during the Holocene. For that purpose coring was successfully applied to sample sediments deposited on the bottom of the fresh water crater lake of Rano Raraku in view of detailed biological and ecological research.
DePaepe, P. and Vergauwen, I.
"New Petrological and Geochemical Data on Easter Island,"
Rapa Nui Journal: Journal of the Easter Island Foundation: Vol. 11
, Article 8.
Available at: https://kahualike.manoa.hawaii.edu/rnj/vol11/iss2/8