Humidity problems that affected the Huasteca monolith known as Lunar Calendar located in Tamtoc Archaeological Zone, San Luis Potosi, were solved by specialists of the National Institute of Anthropology and History (INAH) by draining out the spring where it was found and where it is exhibited to present. This is an alternative measure while archaeologists find the Prehispanic channels that must have solved the problem back then.

Archaeologists Estela Martinez and Guillermo Cordoba Tello are in charge of the task since early 2009, at the place known as La Noria, of solving conservation problems of the vestige also known as Monument 32, since weathering, rain and stagnant water had provoked deterioration of the 2,200 years-old stone sculpture.

Lunar Calendar was found by the INAH Tamtoc Archaeological Project in 2005 at the place where a Prehispanic cistern was located. The 30 tons monolith, which dimensions are 8 by 4 meters and 40 centimeters thick, presents 3 feminine characters, one of them associated with the waxing and waning phases of the Moon. This is the reason why the sculpture dated around 800 BC was related to the lunar calendar.

Cordoba Tello informed that the sculpture is located at the side of a small spring where water still rises. “Since the liquid did not circulate anymore, it stagnated, increasing the level until it reached the sculpture, getting wet 30 centimeters of the bottom.  

“To attend the emergency, during the first months of 2009, a several meters expansive excavation was made on the surface of the spring, to look for the Prehispanic channels that conducted the water to Los Patos Lagoon, but we have not found them yet”.

Nonetheless, excavations helped to drain the water. To present we are monitoring the flow, and it seems that we found a solution until we locate the channels.

A cover was constructed to protect Monument 32 from weather, which also protects a small monticule named Structure 10 from air, sun and rain action.

The archaeologist commented that this work is part of the Origin and Development of Urban Landscape at Tamtoc Project, which also includes the recovery of the lagoon.

One hypothesis indicated that the lagoon was built around the city to protect it, because 7 connected water deposits have been found. “They are small, measuring between 60 and 90 square centimeters; others are hollows that might have been part of the hydraulic system”.

He mentioned that the lagoon recovery work is being conducted with resources of the Temporary Employment Program (PET), implemented by INAH and the Secretariat of Social Development (SEDESOL). 50 employees have been draining water from the lagoon for 6 months.

Guillermo Cordoba commented that at the bottom of the lagoon several archaeological items have been found, which stops them from using heavy machinery to drain water, “the task is titanic because the lagoon measures one kilometer long by 300 meters wide”.

This work has the aim of revitalizing the archaeological site to make it more attractive to visitors. “We have finished the registration cards’ text, and they are ready to be placed at the zone. A mini-guide is in process to be published as well, being the first one edited about Tamtoc”, concluded the archaeologist.