This indicates a footpath passed through Chunchucmil's marketplace and that food was sold or traded around it, the authors say.
"Just who traded in the [Chunchucmil] marketplace is not known," the study concludes.
It "does seem clear, though, that the surrounding region and beyond provided critical commodities to sustain Chunchucmil's permanent residents and visiting merchants of whatever kinds and their retinues," it says.
Food for Thought
The research may also help solve "the vexing question of how large ancient Maya urban populations were sustained," the authors write.
"Conventional wisdom has it that market systems were not important, despite the fact that urban populations often exceeded local carrying capacity using traditional farming methods," said study leader Bruce H. Dahlin.
Maya marketplaces have been tentatively identified in a number of large and important sites, added Dahlin, an archaeologist at the Center for Environmental Studies at Shepherd University in Shepherdstown, West Virginia.
(See an interactive map of famous Maya sites.)
However, "until the emergence of geochemical prospecting techniques, there was no means of verifying them nor if staple foods were exchanged there," he said.
The work provides an important launching point for further studies of markets' roles during the Classic Period, he said.
Written evidence also bolsters the case, pointed out Terry of Brigham Young University.
"[Hernán] Cortés writes about the marketplace, but archaeologists haven't had direct evidence of pre-Columbian Maya marketplaces," he said.
"This study is one of the first to show evidence of markets dating that far back. It is also the first to use soil chemistry to establish lines of evidence."
Dahlin, Terry, and their colleagues report their findings in the current issue of Latin American Antiquity.
(Dahlin, along with team member Timothy Beach of Georgetown University in Washington, D.C., are both former recipients of research grants from the National Geographic Society, which owns National Geographic News.)
Other scientists praised the technique and its findings.
"This is an interesting, methodical advance in the detection of markets, which have been source of great controversy in Maya archaeology," said Stephen D. Houston, an anthropologist at Brown University in Providence, Rhode Island.
"This helps to reorient and focus views of ancient Maya economy, suggesting the possibility that the Maya had markets similar to Aztec markets seen many years later."
Houston added that the researchers had "properly couched their study as a hypothesis" and that other scientists in the last few years have found probable markets in Mexico and Guatemala.
"I suspect this discovery will lead people to pay more and more attention to possible sites," he said.
Robert Sharer, an anthropologist at the University of Pennsylvania Museum of Archaeology and Anthropology in Philadelphia, called the study "important."
Sharer said he and other archaeologists have maintained that the Maya had centralized markets.
He speculates that the population pull of markets could have made them a focal point for the governing elite.
"By attracting large numbers of people together on a regular basis, markets may have provided opportunities for social interaction and the exchange of ideas. And they may even imply a measure of centralized control over the economy by Maya rulers."
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