Geologist are constantly aiming at obtaining more precise and detailed data, such as how long a mountain range takes to form; how fast tectonic plates have moved during the history of the Earth; how and why the Earth’s climate changes; or how long the planet needs to recover from a catastrophe such as that caused by the meteorite which fell to Earth 66 million years ago (Ma.). That event resulted in one of the greatest biological catastrophes in the history of the Earth, including the disappearance of almost all dinosaurs (except birds) and put an abrupt end to the Cretaceous period.

Research at the Faculty of Science and Technology of the University of the Basque Country (UPV/EHU), entitled Detailed Correlation and Orbital Control of succession during the Upper Maastrichtian in the Basque-Cantabrian Basin and focusing on the last 3 million years of the Cretaceous period, merited the prize for the best publication in 2013 in the specialist Boletín Geológico y Minero journal of the Instituto Geológico y Minero de España (IGME). This research managed to detail exactly the chronology of the climatic, magnetic and biological events prior to the great extinction of 66 Ma.

The traditional method for establishing absolute chronological and geological events has been using radiometric dating methods, based on the decomposition of radioactive isotopes. This method, however, is only applicable with the intervals such isotopes have, and so the ages of those zones thus bereft can only be estimated through interpolation.

As the title of the research suggests, the method applied by this research team was based on a different principle, concretely on what is known as orbital control, which analyses gravitational interactions between the Earth, the Moon, the Sun and the planets of the Solar System (principally Jupiter). These interactions produce periodic variations of the terrestrial orbit, known as Milankovitch cycles, in honour of the Serbian astrophysicist who discovered them. It is thus known that the terrestrial orbit varies with intervals of one hundred thousand and four hundred thousand years; the inclination or obliquity of the Earth’s axis every forty thousand years; and the orientation of this axis in relation to the sun approximately every twenty thousand years.

Source: Basque Research - See full article