The International Information Center for Geotechnical Engineers

Thursday, 21 March 2019 01:00

Geological paradox found in African island

Geological paradox found in African island Geological paradox found in African island.

Scientists have made a very mysterious discovery about the rock formations on Anjouan island, located North-West of Madagascar.

The team from the Columbia University found that almost half of the island's mountain is made up of quartzite rocks which shouldn't be there in the first place. "This is contrary to plate tectonics. Quartzite bodies do not belong on volcanic islands," Dr. Cornelia Class, a geochemist at Columbia University, stated. Some local reports had mentioned the presence of quartzite on the island but the group was the first to confirm it. 

Anjouan Island was formed due to volcanic eruptions in a procedure that is similar to Hawaii's formation. It lies on an ocean basin that has formed as tectonic plates pull apart. During this process, magma emerges and cools to form a new crust. Rocks from ocean basics are basaltic. "There is nothing there that could form a quartzite," Class said. Quartzite is normally found in regions with high pressures and temperatures. 

However, quartzite is not the first non-volcanic rock formation found on the island. Occasionally, during the last century, some geologists had reported noticing non-volcanic rocks on the island. Even Dr. Class had tracked such formations when conducting her PhD research on the island.  "All those years, it has bothered me that I didn't understand how those rocks got there," Class added. 

The researchers found out that natives utilized quartzite stones to sharpen their knives. Therefore, pieces of rock were transferred to riverbeds and villages.

Currently, the team is examining the data in order to determine the quartzite geometry and size on the island. Until now, they are not able to explain the existence of the rock. They just know that the crustal quartzite ended up in the ocean basin and emerged from the seabed along with volcanic rocks. "This is what nature presents, sometimes. It's something we consider impossible, but then we find it, and once we find it, we have to explain it," Dr. Class said. She also added that field survey is challenging as the island is filled with a thick layer of soil and vegetation.


Read 680 times Last modified on Thursday, 21 March 2019 15:20

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