Faculty of Science and Technology of the University of Coimbra / Courtesy
Saint Peter of Moel
The cliffs of São Pedro de Moel hold the most complete geological record in the world from a critical period of the Jurassic.
São Pedro de Moel enters the important records of archaeological research worldwide.
As coastal cliffs of Saint Peter of Moel and the Asturias (Spain) maintain the more complete record known worldwide from a critical period in Earth’s history.
The period in question is the transition between the Sinemurian and Pliensbachian floorswhich occurred approximately 193 million yearsin the Early Jurassic.
The revelation comes in a new report, which included researchers from the Center for Marine and Environmental Sciences at the University of Coimbra.
These two Iberian regions are authentic “natural laboratories”, reads a statement. Detailed analysis of ammonite fossils has allowed us to refine the geological time scale with unprecedented precision.
We analyzed, in detail, ammonite fossilsancient marine cephalopod molluscs; Thus, researchers were able to refine the geological time scale with unprecedented precision.
The sections of Água de Madeiros (Marinha Grande) and Pedra do Ouro (Alcobaça) They are global references for their stratigraphic continuity and fossil richness, surpassing in detail many other European regions.
“As the fossils are very well preserved and appear continuously, it is possible compare with great precision these layers in Portugal and other European countries, helping to build a more accurate geological time scale at a global level”, analyzes Luís Vítor Duarte, co-author of the study.
This investigation shows that significant variations in sea level and changes in global carbon cycleidentified through geochemical analyses, were associated with episodes of extinction of groups of ammonites and the emergence of new species more adapted to environmental changes.
This way, it becomes clearer how the environmental crises influenced the evolution of marine life around 190 million years ago.
Each “horizon” of amonites – fundamental unit used in dating these geological records – corresponds on average to approximately 100 thousand yearsenabling a high-resolution reading of Earth’s past.
This also provides new elements to understand the paleobiogeographical connections between different Lower Jurassic marine basins, including discussions related to the so-called “Hispanic Corridor”, an ancient marine connection between the Tethys and the Pacific that may have facilitated the dispersal of marine organisms.
