A third way to rift continents

摘要

Vast continental regions have experienced volcanism precisely where 1,000-kilometre-scale crustal blocks were pulling apart. For example, such rifts began to cut across much of Africa about 140 million years ago, and distributed, low-flux volcanism continues in that region today (Fig. 1). Such broadly distributed, synchronous activity is hard to fit into standard theories of rifting and volcanism. Writing in the Journal of Geophysical Research, Fourel et al.' suggest an explanation for this activity based on laboratory experiments with fluids whose densities depend on temperature and composition.