Eruptions Cleared Path for Dinosaurs

摘要

In a geologically brief catastrophe 200 million years ago, massive rivers of lava oozed out of fissures in the ground and paved over a continent-size swath of land, reports an international team of researchers. This eruptive outpouring— the largest known in Earth's history— may have killed off much of the planet's life and led to the coronation of the dinosaurs as rulers of the Jurassic period. The volcanic crisis hit at the end of the Triassic period, when all of Earth's continents huddled together in a single land-mass called Pangaea. Within the short span of a few million years, black basalt erupted along the central spine of this su-percontinent, eventually spreading over an area nearly the size of Australia. Soon thereafter, in the Jurassic period, the At- lantic Ocean opened up, ripping apart Pangaea and scattering these basaltic formations across four of today's continents, according to Andrea Marzoli of the University of Geneva in Switzerland and his colleagues.