THE BIGGEST LAVA OUTPOURING in history probably took place about 200 million years ago. A team of geophysicists has just put together the final jigsaw piece in a puzzle relating separated basaltic layers in spots as far flung as the Hudson River Palisades, Brazil, Europe, and Africa. What started out as an Australia-sized blacktop in the heart of the ancient super-continent Pangea was later torn asunder by the tectonic forces, which carried the fragments to places all around the Atlantic rim, making discovery difficult until now. The immense flow, now referred to as the Central Atlantic Magmatic Province, might have played a part in the mass extinctions occurring at the boundary between the Triassic and Jurassic eras. (Marzoli et al., Science, 23 April 1999).