Earth has amnesia. Scientists study places where geological layers are missing

Scientists are exploring areas of the earth where time is mysteriously absent. In rock formations, known as “geological disagreements,” millions of years of Earth’s history are absent. Scientists now have a better idea of ​​why this happened. About this writes Vice, referring to a letter from researchers.

Like people who experience temporary amnesia, our planet also has the same “memory” gaps. And they can last hundreds of millions of years. In fact, there is a break in sedimentation. With the successive deposition of rocks (and their joint transformation, including folding), a so-called consonant occurrence is formed, in which each layer has elements of occurrence and deposition of each geological time interval that is coincident with other layers, and are presented in a section.

If any of the points listed above are violated, then they speak of disagreement. At the same time, disagreements occur at a very different historical stage. Scientists suggest that natural forces somehow prevented the preservation of rainfall from past eras.

“There is one big question in the overall picture of the planet’s structure – the degree of accuracy in which the record of the Earth’s sedimentary rocks is complete, rather than fragmentary, with significant sections removed by erosion,” writes Rebecca Flowers, a geologist at the University of Colorado at Boulder. “To find out the history of the Earth more fully, you need to understand the relationship between surface processes (such as erosion), deep earth processes, and long-term biological, climatic, and environmental changes”.

Flowers recently published a study on the Great Disagreement – a long interruption in sedimentation that can be traced to the Precambrian sediments in many parts of the world. In large areas, hundreds of millions of years have been deleted from the geological record.

Flowers and her colleagues suggest that the gap was created by “regional tectonic features, not asynchronous global phenomenon”. The team came to this conclusion by examining the mismatch in granite exposure on Pikes Peak in Colorado, although this is not the only place where hidden secrets about this remote past are kept.

“We are actively working on other facilities in North America, including the Grand Canyon, where the iconic“ Great Disagreement ”is perhaps most clearly represented”, said Flowers. – Then we plan to focus on sites on other continents.

To solve this problem, the team investigated samples of minerals and crystals from rocks, such as hematite and zircon, which can be used to reconstruct the thermal history of sediment layers. The results showed that the older “basement” rocks at Pikes Peak were destroyed before the first snowball appeared and “therefore cannot be a product of glacial erosion.”

The study also casts doubt on the hypothesis that erosion associated with the Great Dissent could populate the Earth with the nutrients that caused the Cambrian explosion, an event that marked the sudden emergence of a complex life of about 541 million years ago.

Researchers believe that tectonic processes associated with the formation and collapse of Rodinia, the supercontinent that existed about a billion years ago before the Snowball era, could erase memory at Pikes Peak. But more research will be needed to uncover all the uncertainties of the Great Disagreement.

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