Les glaciations du Protérozoı̈que

The first glaciations of the Earth are very intriguing, because they took place at low latitude and altitude. In this paper, focusing on the understanding of the Neoproterozoic glaciation, we quantify through climate model simulations the plausibility of two major causes: change in Earth Obliquity and fragmentation of the Supercontinent Rodinia. We demonstrate that high obliquity is inconsistent with the climate produced by the model during one of the glacial phases. On the contrary, we are able, using a climate–carbon coupled model, to quantify the dramatic decrease in atmosphere CO 2 due to the fragmentation of the Supercontinent, which leads to favourable conditions for the establishment of a snowball Earth. To cite this article: G. Ramstein et al., C. R. Geoscience 336 (2004).