(ORDO NEWS) — One of the most important features of the rocks is that they allow geologists to look into the Earth‘s past, and the deeper they go into the rock layers, the older the rock is found.
But sometimes geologists find a gap in the record when layers of rocks are located on top of older rocks, and there are no layers of middle age between them.
The “inconsistencies” found may be the result of no new layers of rock having been laid down over the years, or that the rock has been eroded away by geological processes.
Such inconsistencies are very common, but from time to time there is just a huge inconsistency that requires some explanation.
In 1869, geologist John Wesley Powell explored the Grand Canyon and noticed a gap in age between the rock layers. On top of the 1.4-1.8 billion year old rocks was a rock that was only 520 million years old.
More bizarre, however, was that elsewhere throughout North America and around the world there was an absence of rock dating back to just over 550 million years ago.
So what happened?
One suggestion, made in 2019, is that the rupture was caused during the “Earth snowball” period, whose proponents believe that the Earth’s surface once completely froze over and the planet became like a snowball.
According to this theory, the missing rock could be explained by the growth of a glacier and then by erosion that carried it into the ocean.
However, other studies have questioned this hypothesis. In a 2020 study, Pikes Peak Rock (Colorado, USA) was studied.
Here, older rock broke through to the surface and then underwent severe erosion that began about 717 million years ago.
This means that the absence of rock was caused by processes not associated with the formation of a “snowball”.
The research team believes that the discrepancies observed around the world did not have a common cause, even if they occurred at the same time.
The great discrepancy that took place in North America, according to scientists, was probably caused by the breakup of the supercontinent Rodinia 700-800 million years ago, as a result of which older rock rose to the surface, and newer rock was swept into the ocean.
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