What is today a desert, in the past was an agricultural landscape. In territories that remain hostile to subsistence, societies thousands of years ago had developed technologies to make life sustainable in the Feedback.
The hydraulic system discovered by the archeology team of the Miriguaca project demonstrates the existence of various irrigation networks with different scales of use and magnitudes.
The discovery was made possible through the study of satellite images that revealed traces that caught the attention of the team currently led by the archaeologist Lorena Grana. Already on the ground, the lines turned out to be irrigation canals, and in an area where the lines converged, the excavation revealed a dam.
The pond is located in the middle of the irrigation network, 5 kilometers from the Miriguaca river, for a total route of 10 kilometers to the end of the cultivated fields. For Lorena Grana, this means that the purpose with which they accumulated the water was to recover the flow. “Possibly they were losing the flow due to filtration or evaporation, so what they did was put the pond in order to recover the flow. Clearly what they are showing is a very thorough knowledge of water management and slope management, because the canals are simply dug into the ground. And what surprises us is how with simple technologies the farmers of the past were able to provide solutions to the limitations such as the scarcity of water in such a desert area, and the management of the slopes “, the archaeologist told Catamarca/12.
The dam consists of a very simple construction, a semicircle of earth. The excavations made it possible to understand that it consists of a pond of at least 370 cubic meters and an outlet duct built with flagstones. The outlet frame has a trapezoidal shape and the end of the pipeline is constructed as a small stilling chamber, to control the speed of the water outlet. The function of the chamber is to slow down the water when it leaves the dam to prevent erosion of the channels.
The construction techniques were based on taking advantage of the natural slope of the land to accumulate water, then they made a mound of earth to contain the water, and the outlet duct was made with carved and arranged stones.
According to Grana, one of the most complex analyzes in this type of structure is to know when it was built. The dating is done through an analysis by radiocarbon, with which you can determine the age of materials up to 50,000 years old. But in the country it is not done. So a dating with this system has become unsustainable between the pandemic and the economic crisis.
Grana explained that another resource that archaeologists have to date, is to take into account the context in which the find is found and the surrounding materials. Starting from this It is estimated that the irrigation network and the dam were used in the last 1000 years, it could even be prior to the Inca period. In addition, the vessels found in the excavation make it possible to determine that the population had contact with other populations of Belen.
For Grana, one of the importance of the find is that it shows “the strong knowledge that these peasants of the past had for managing the landscape. The surprising thing is not so much the dam itself, but these finished knowledge that allowed him to generate agricultural oases in such a desert area. The moment of use was just as arid as the current ones, and they were able, with very simple technologies, to generate large areas of cultivation ”, he concluded.
The team that has been working in the area since 2006, has revealed 21 archaeological sites so far that date back to the last 4000 years.