Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

In Barrika, the remains of a Cretaceous glaciation have been found

On the beach of Barrika, evidence has been found that there was a glaciation 80 million years ago. This discovery goes against a deeply rooted idea: In the Cretaceous, the Earth was in a “supergreenhouse” situation, at the highest temperatures in the history of the planet.

“The discovery involves a paradigm shift that questions the very basis of paleoclimatic models.”

The evidence found in Barrika is undeniable according to the researchers and shows that a glacier had been pouring large icebergs into the sea for 1.84 million years. In fact, these icebergs and the dynamics of the glaciers themselves have been found using innovative methodologies such as high-resolution sedimentological analysis, biostratigraphy with nanofsils, scanning electron microscopy, micro and nano-X-ray tomography and U-Pb geochronology. The research was led by researchers from twelve institutions, including the UPV/EHU and the University of Zaragoza.

To date, no glacier remains have been found at such a low latitude after the Carbonifero-Permian ice age (300–255 million years ago). At that time, the glaciers reached up to 30°. The one in Barrika, located at 35° latitude, occurred at a time close to the thermal maximum modeled for the Mesozoic. Therefore, the researchers emphasize that the discovery implies a paradigm shift that forces them to question the very basis of paleoclimatic models, at least for the Mesozoic.

In fact, according to the evidence found in Barrika, the researchers believe that the paleoclimatic indicators currently in use must be thoroughly reviewed and suggest that geochemical tools used to reconstruct past temperatures are likely to systematically calculate Cretaceous temperatures from above.