The billion’s scar of the time when the continent is almost torn apart

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Quick facts

Name: Midcontinent rift

Location: US Middle West

Why it’s amazing: The break almost broke North America by half about 1 billion years.

The Broken Heart of North America is an ancient rift valley in the Midwest of the United States. The Ruff began about 1.1 billion years ago because of the tectonic forces that are pulling what is now the North American continent in opposite directions. The evidence suggests 100,000 years After it started, but scientists are not sure why.

The Rift Valley is shaped like a horseshoe extending from Kansas north to Superior Lake and south again to Michigan, according to cards From an article from 2013 at Nature “Although some evidence It suggests that the break can extend to the south. Geologists calculate that the break was once measured about 1900 miles (3000 kilometers) and created a lung wide as the Red Sea, but the greater part of the structure is already buried under a thick layer of sediment, according to The National park (NPS).

The only parts of the break that are visible today are close to the Superior Lake, which exhibits huge blocks of basalt and other cliffs related to the rift, according to NPS. The basalt is dark, fine-grain-and therefore a thick-scab formed by a fast-cooled lava. As the Earth’s crust was torn during the breakage process, Magma rose to fill the crack, creating a belt of hardened lava and magma in the valley.

The break is probably open in the present Midwest because the earth’s crust has already been fragile there – a large magma spot can weaken the surface and seal the fate of the region, according to NPS. As smoking progresses, the melted rock rose and trigger volcanic eruptions, delaying huge amounts of dense material, such as a basalt, which made the rift valley sink into the crust.

“Spectacular failure”

For reasons that scientists discuss, the break and eruptions stopped, so that the sludge settled at the top of the volcanic material. But the Rift Valley did not stop sinking, because the weight of the sludge pushes the structure deeper into the crust.

Related: Lifting dome: Utah’s “belly button” that split scientists from its opening

The crushing is followed by a period of compression in which pieces of bark on each side of the rift valley are assigned together. This pushed the volcanic material and the sediment, according to the NPS, exposing sections of the Rift Valley, which were then covered with sediment.

Cyclic growth and glaciers over the last 2.5 million years have removed part of this precipitate, which is why parts of the break are still visible. Near the Superior Lake, especially on the Keweenw Peninsula of northern Michigan, they appeared basalt and copper-rich rocks. People have gained this honey for at least 8000 years – And although mines are closed in the late 20th century, the industry is now Seeing a revivalS

Why the gap ends after 100,000 years remains a little unclear.

“This is a grand failure” G. Randy KellerProfessor of Geophysics at the University of Oklahoma and director of Oklahoma geological survey, the Nature article for 2013 “How this feature can simply reorganize the root of the Earth in the Superior Lake region and fail to break the continent is quite incredible.”

Incredible places

-El cono: The mysterious sacred “pyramid” hidden deep in the tropical forests of the Amazon

– Folded rocks of Iran: crushed mountains at the intersection of Asia and Europe

– Wilkes Land Crater: The giant hole in the gravitational field of Eastern Antarctica is probably caused by meteorite

Geologists have been exploring this question for more than a decade, with some scientists failure to an episode of mountain construction along the Atlantic coast in North America. Other researchers reject this theory, Instead, it offers The fact that the break was over when the sea opened between Laurentia and the Amazon – the geological nuclei of North and South America.

Meanwhile sections of the Rift Valley in Kansas have attracted attention from resource exploration companiesS Basalt can react with water to make hydrogen, which is a source of clean energy and ingredient in key chemicals, Live Science reports earlier.

Discover more Incredible placesWhere we emphasize the fantastic story and science behind some of the most dramatic landscapes on Earth.