A mystery that has puzzled scientists for more than a century: in the geological record, large chunks of the Earth’s crust are missing, and where is it?
Using satellite imaging technology taken from space, scientists recently discovered that part of the Earth’s crust disappeared due to severe glacial erosion .
Regarding the current location of the missing rocks, scientists believe they were swept out to sea, according to news site Indy100 .
Hundreds of millions of years old rocks in Grand Canyon, Arizona (USA) – (Photo: IFL SCIENE).
This event occurred during a period known as “snowball Earth”, when almost the entire planet was covered with snow and ice.
Glacial erosion has caused a void to appear in the sediment. At the same time, it also causes the age of rocks to change drastically in some places that are missing in the Earth’s crust. This results from the erosion of earlier layers of rock being replaced by younger rocks.
In 1869, at the Grand Canyon in Arizona (USA), scientists discovered the phenomenon of missing rocks : 500 million year old rocks lying on top of 1,700 million year old rocks and there are no rocks in between. this moment.
The study’s lead author, Dr. Brenhin Keller from the Berkeley Geochronology Center, explains that the scale of rock loss is enormous.
With colleagues, he estimates that one billion cubic kilometers of Precambrian rocks have been lost.
The scientists’ theory suggests that much erosion occurred before the start of the Phanerozoic era – also known as the Epigenetic era – and they present evidence that rock crystals from that period have isotopes hafnium and oxygen.
These events are consistent with old rocks being eroded and deposited at low temperatures under the sea. At the same time, this is why there are many asteroid impact craters on Earth that are less than 700 million years old and only two that are older than that.