The incredible Iguazu Falls of South America
The Iguazu Falls of South America are among the most spectacular falls in the world. At the border between southern Brazil and northern Argentina, they drop 80 metres (260 ft) in two steps over layers of black basalt rock.1 Islands along the edge break the flow into numerous separate waterfalls. When the river is high, some 300 waterfalls cascade along the 2.7 km (1.7 mile) edge—longer than either the Niagara or Victoria Falls.
The basalt exposed at the falls is just the top part of an enormous pile of successive volcanic lava flows some 1,000 metres (3,300 ft) thick. Called the Serra Geral formation, these igneous rocks cover a huge area, some 2,000 km (1,300 miles) from north to south and 1,000 km from west to east, within an area geologists call the Paraná Basin. They are described as a large igneous province (LIP) called the Paraná Traps.
The Paraná Traps represent one of the largest eruptions of volcanic magma onto the continents anywhere on Earth. Global-scale forces within the earth mobilized the red-hot, basaltic magma and pushed it up to flood a large area of the continent. This crustal movement eventually led to ocean basins sinking, the continents uplifting, and the floodwaters receding from the earth.
These basalts have been assigned an evolutionary age of some 130 million years, i.e., early Cretaceous. However, the geology transformation tool2 reveals that the volcanic rocks were emplaced some 4,500 years ago in the middle of Noah’s Flood while the floodwaters were rising on the earth. The basalt was emplaced quickly. Not long after, the waters of the Flood peaked to cover the whole continent to a depth of a kilometre or more. Forces within this water eroded the top of the Paraná Basin to produce a relatively flat plain still visible over large areas today.
As this continent continued to uplift, the floodwaters still on the land flowed into what is now the ocean until they were gone, as described in Genesis 8. In the process they eroded canyons and waterfalls. In the 4,500 years since the end of the Flood, the Iguazu River has flowed across the Brazilian Plateau, dropping down at the Iguazu Falls, and joining the Paraná River where Brazil, Argentina, and Paraguay meet.
The incredible Iguazu Falls and the rocks over which they flow are a tiny reminder of the power of flowing water, and of the true history of our world, which has shaped the heritage of everyone alive today.
References and notes
- Stevaux, J.C. and Latrubesse, E.M., Iguazu Falls: A History of Differential Fluvial Incision; in: Migon, P., (ed.), Geomorphological Landscapes of the World, Springer, ch. 11, pp. 101–109, 2010. Return to text.
- Walker, T., The geology transformation tool: A new way of looking at your world, Creation 43(2):18–21, 2021; creation.com/GTT. Return to text.
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