An international team of archaeologists from the United States and Mexico has found several biomarkers of cacao in soil from karst sinkholes that dot the Yucatan Peninsula.
The ancient Maya considered cacao beans to be a gift from the gods and even used them as currency because of their value.
As such, cacao bean production was carefully controlled by the Maya leaders of northern Yucatan, with cacao trees only grown in sacred groves.
In the new research, Brigham Young University’s Professor Richard Terry and colleagues aimed to identify locations the Maya used to provide the perfect blend of humidity, calm and shade required by cacao trees.
While the drier climate of the Yucatan peninsula is inhospitable to cacao growth, they realized the vast array of sinkholes common to the peninsula have microclimates with just the right conditions.
They conducted soil analyses on 11 of those sinkholes and found that the soil of nine of them contained evidence of theobromine and caffeine.
They also found evidence of ancient ceremonial rituals — such as staircase ramps for processions, stone carvings, altars and offerings like jade and ceramics, including tiny ceramic cacao pods — in several sinkholes.
“We looked for theobromine for several years and found cacao in some places we didn’t expect,” Professor Terry said.
“We were also amazed to see the ceremonial artifacts. My students rappelled into one of these sinkholes and said, ‘Wow! There is a structure in here!’ It was a staircase that filled one-third of the sinkhole with stone.”
The findings indicate that cacao groves played an important role in ancient rituals and trade routes of the ancient Maya, impacting the entirety of the Mesoamerican economy.
A 70-mile Maya highway in the area that was the main artery for trade passes near hundreds of sinkholes, so it is likely that the leaders who commissioned the highway development also controlled cacao production.
The evidence of cacao cultivation alongside archaeological findings also supports the idea that cacao was important in the ideological move from a maize god to a sun god.
In one sinkhole near Coba, Mexico, a village 45 minutes from modern day Tulum, the archaeologists found the arm and bracelet of a figurine attached to an incense jar and several ceramic modeled cacao pods.
They also found remnant cacao trees growing there, making it quite possible that this sinkhole, named Dzadz Ion, was the location of a sacred cacao grove during the Late Postclassic period (1000 to 1400 CE).
“Now we have these links between religious structures and the religious crops grown in these sinkholes,” Professor Terry said.
“Knowing that the cacao beans were used as currency, it means the sinkholes were a place where the money could be grown and controlled.”
“This new understanding creates a rich historical narrative of a highly charged Maya landscape with economic, political and spiritual value.”
The study was published in the Journal of Archaeological Science: Reports.
Richard E. Terry et al. 2022. Soil biomarkers of cacao tree cultivation in the sacred cacao groves of the northern Maya lowlands. Journal of Archaeological Science: Reports 41: 103331; doi: 10.1016/j.jasrep.2021.103331