One of the rarest pieces in our Olmec exhibition at the de Young is a carved human bust made of a tropical variety of cedar tree. Over three thousand years old, the bust has survived this long because it was buried at the bottom of a freshwater bog for most of its life.
Archaeologists believe it was placed in the bog, along with thirty-six other busts, by the Olmec as part of a large offering, probably in response to a long-term problem facing the community, such as a flood or drought. The busts were bundled in vegetable mats and buried along with other objects of high value—some of which are also in the exhibition.
Researchers think the Olmec chose the spring, named El Manatí for a nearby hill and the manatees that were abundant in the area, as a site for important offerings because it represented a culmination of important elements. The Olmec believed water and mountains were imbued with sacred qualities, including fertility, and saw tall hills both as a meeting point between the earth and the sky and as “mansions of the rain god.” The area was also abundant in hematite, an iron-rich red pigment that researchers believe the Olmec associated with blood.
The thirty-seven busts are the only examples of Olmec woodwork so far discovered. Wood naturally biodegrades and has a shorter lifespan than stone, and until the busts were discovered archaeologists could only guess that Olmec artisans worked with wood as well as stone, clay, and jade.
The bog conditions that allowed for the busts to be preserved were delicate. Normally wood rots in water, but when enough organic material (branches, leaves, mosses) sinks to the bottom it forms a layer of silt, sealing out oxygen and sealing in everything under. In this case, it sealed in the busts and other objects and preserved them just as the Olmec had left them. Bogs are generally acidic environments, and the organic material that falls to the bottom is so waterlogged it carries very little oxygen; the combination of higher water acidity and no oxygen prevent the microorganisms that normally cause decay from surviving.
Samantha Barclay-Saxon is a communications intern. This is her first post.