International Research Team Reveals Timing of Andes Plateau’s Uplift
An international research team, including Prof. Dr. Andreas Mulch from the Senckenberg Biodiversity and Climate Research Center and Goethe University Frankfurt, has delved into the uplift history of the Andes Plateau using stable hydrogen isotopes in volcanic glass. Their study, recently published in the journal Proceedings of the National Academy of Sciences (PNAS), highlights that specific regions of today’s biodiversity hotspot only reached their present elevation within the last 13 to 9 million years. This timing coincides with the formation of the Andes, a significant factor in South America’s biodiversity development.
The slopes of the Andes, spanning about 9,000 kilometers, harbor some of the world’s most diverse ecosystems and are home to iconic species like vicuñas, llamas, spectacled bears, and Andean foxes. The unique biodiversity in the region also includes flora and fauna in the Amazon rainforest, which is estimated to contain around 40,000 plant species. The Andes’ formation and alterations have played a pivotal role in the evolutionary history of South America’s biodiversity.
Prof. Dr. Andreas Mulch explains, “We have been asking ourselves since when this has actually been the case.” To investigate the uplift history of the Puna Plateau in the south-central Andes of northwestern Argentina, an international research team led by Dr. Heiko Pingel of the University of Potsdam conducted extensive fieldwork. The Andean plateau, averaging an elevation of four kilometers, is the world’s second-largest mountain plateau.
The team aimed to clarify when the plateau reached its current elevation and how it affected South America’s environmental conditions. Prior estimates of the plateau’s uplift timing varied widely, making it challenging to comprehend the forces that shaped the plateau’s unique characteristics and their impact on the region’s environment.
In this new study, the team analyzed hydrogen isotope ratios from million-year-old volcanic glass collected during field studies in comparison to data from the lower foothills. Prof. Dr. Mulch explains that “the volcanic glass reveals the altitude of our study area at different times by storing the elevation-dependent precipitation at that time.” Their findings indicate that the Puna Plateau’s elevation has risen approximately two kilometers since the middle to late Miocene, occurring 13 to 9 million years before the present day.
Mountains play a critical role in influencing wind and precipitation systems and can act as both corridors for and barriers to species dispersal. The research not only sheds light on geological processes in the central Andes but also elucidates the role of the Andes in the evolution of South American biodiversity.
Prof. Dr. Mulch emphasizes the interconnectedness of the Earth’s systems and the importance of geobiodiversity research in understanding complex processes of the past and finding solutions for the future.