A team of scientists from the National Scientific and Technical Research Council (Conicet), together with researchers from Germany and the United States, has conducted research on the geological processes that shaped the Andes, specifically in its central sector, during the Paleogene period (between 65 and 40 million years ago).
The findings allow reconstructing the history of the Andean uplift and understanding the climatic conditions prevailing at that time.
## The ancestral landscape of Mendoza: tropical lakes and giant reptiles
The study focused on the analysis of rocks from the Divisadero Largo Formation, located in Mendoza.
These formations originated in sedimentary basins, depressed areas where materials transported from high areas accumulate.
It was discovered that 65 million years ago, the region was dominated by:
– Shallow lakes.
– Fossil remains of turtles, crocodiles, and boas, suggesting a warm and humid climate.
However, researchers also identified drastic climatic changes, as gypsum layers appear in upper levels, indicative of:
– Arid conditions.
– Low humidity and predominant evaporation.
## Methodology and international collaboration
Conicet’s doctoral fellow, Lucas Lothari, explained that the work began with the review of previous studies.
Subsequently, satellite images were used to select appropriate sites for exploration.
Field tasks included:
– Rock description.
– Sampling and measurements.
– Sample processing in Germany and analysis in U.S. laboratories.
International cooperation was fundamental for project funding.
## A period without tectonic activity?
Until now, the Paleogene was a stage poorly understood in the evolution of the Andes.
While the Cretaceous (100 million years ago) and the Oligocene (30 million years ago) have clear records, the theory of “tectonic stillness” during the Paleogene had been proposed in other regions, that is, a long period without significant movements.
However, evidence of mountain growth has been found in the Aconcagua area, suggesting that the Paleogene may have had tectonic activity, although not of great magnitude.
## Relevance of geological studies
“Understanding the evolution of the Andes and paleoclimatic changes not only allows us to better know our territory but also anticipate future geological processes,” stated Lothari.
This study represents a crucial advance in the geological history of the mountain range, opening new doors for future research in one of the most important regions of South America.
