Iguazu from aboveThese falls illustrate a property of flood basalts (aka LIP or large igneous provin

Iguazu from aboveThese falls illustrate a property of flood basalts (aka LIP or large igneous province), which have emerged in huge quantities from large fissures in the crust at odd intervals throughout Earth’s history, often contributing to mass extinctions along the way. As eruption succeeds eruption, sometimes with a prolonged gap in between which sees the development of a soil horizon that is then covered by the next layer, they form a series of distinct layers known as trapps, from the German for steps. The Deccan (roughly 65 million years old, and a factor in the death of the dinosaurs) and the Siberian (251 million years old, and the likely cause of the end Permian mass extinction, the worst ever seen in which ‘life nearly died’) trapps are the world’s most famous.These trapps came about as South America split from Africa some 132 million years ago. As in Africa today the rifting process, prompted by rising heat from the mantle (whether a plume or convection current) starts with a huge rift valley as the continental crust is literally pulled apart in slow motion, and bleeds lava all over the surface. Bit by bit a new sea grows (like the Red sea between Africa and Arabia in the present geotectonic contet), leaving the lavas split between two continents. The remnants of the other half of the Parana-Etendeka trapps lies in Namibia and Angola.Since then erosion has done its work, removing much of the original lava. The Parana river is continuing it, as it cuts back into a layer of this basalt, plummeting onto the one below. This photo was taken above the Brazillian side of the falls, showing their full spread. Anyone visiting should spend a day in Brazil and a couple in Argentina to get the full glory. Airpano who took the photograph are a team of Russian photographers who produce amazing 3d panoramas from helicopters, their site is well worth a visit, see the link below.LozImage credit: Air Panohttp://www.airpano.com/ -- source link

More pics about