1988/04/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
We have already written in these pages of the magazine about the disappearance of dinosaurs, and it seems that we will have to continue writing, because new theories are emerging to explain this fact. The latter is due to two American geochemists, Robert Berner and Gary Lans.
According to them, the explanation could be in the decrease of atmospheric oxygen. Analyzing the composition of the air trapped in the Ambar, 80 million years ago there was 50% more oxygen than today. The amount of oxygen has been decreasing since then.
So far it has been considered that the composition of the atmosphere has remained approximately constant from the very moment of its creation. The oldest air samples known to date from this study of the Americans were trapped in polar ice and their age was about 160,000 years. During this time the composition of the atmosphere has remained constant.