Striking astronaut photos reveal the hidden beauty of Zimbabwe’s 2.5 billion-year-old ‘geological wonder’ — Earth as seen from space

This intriguing astronaut photo reveals the hidden beauty of Zimbabwe’s vast Great Dyke, a huge seam of ancient magmatic rock packed with precious minerals.

The Great Dyke stretches approximately 342 miles (550 kilometers) across central Zimbabwe, from the outskirts of the capital Harare in the northeast to near Bulawayo, the country’s second-largest city, in the southwest. It is 2 to 8 miles (3 to 13 km) wide and includes hills that rise up to 1,500 feet (450 meters) above the surrounding plateau, according to NASA’s Earth Observatory.

Despite its name, this massive structure is not actually a dike, but a vertical sheet of frozen magma that cuts through an existing rock layer. Instead, it is a lopolis, similar to a dyke but formed parallel to pre-existing rock slabs and more flat and lenticular or dish-shaped.

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According to the Zimbabwe Geological Survey, the Great Dyke is believed to be the longest continuous igneous intrusion or uplifted magmatic structure anywhere on Earth.

The astronaut’s photo shows the southernmost tip of the structure, about 125 km (78 miles) from Bulawayo. In 1983, astronauts aboard the Space Shuttle Challenger also captured impressive photos of the southern half of the structure, and in 2003, NASA’s Terra satellite photographed the entire length of the lopolis (see below).

Geologists believe that lopolis formed about 2.5 billion years ago when magma from the Earth’s mantle gradually seeped upward through plate faults. This means that this structure has existed for more than half of Earth’s approximately 4.5 billion year history.

This magma is rich in valuable minerals that are normally locked deep beneath the Earth’s crust, making the region a mining hotspot. According to Mining Zimbabwe magazine, there are currently at least six major mines along the length of Lopolis.

According to the Earth Observatory, the Great Levee is rich in important metals such as gold, nickel, copper, titanium, iron, vanadium and tin.

But it is best known for its vast platinum deposits, the third largest of its kind on earth, and its unusually pure chromite, which contains high levels of chromium, a key ingredient in stainless steel production, according to the Zimbabwe Mines Authority.

The Great Dyke is also rich in rock used for carving, “resulting in an artist’s paradise akin to the marble quarries of Greece,” local artist Michael Nyakusvora writes on his website.

“Zimbabwe’s Great Embankment is more than just a line on a map, it is a lifeline of economic opportunity.” [and] It is a geological wonder,” Mining Zimbabwe said.