Scientists have studied a 50-million-year-old glacial climate.
- During one of the longest ice ages, glaciers reached the equator.
- The idea of a long frozen earth then led to the mystery of how he could live his first difficult life.
- New discoveries claim that it helped him with the same impacts that caused the recurrence of the glacier in the Quaternary.
Before the beginning of antiquity the earth froze several times from pole to pole. Not for tens or hundreds of thousands of years, but for tens of thousands of years, as in the era of mammoths and Neanderthals.
“One of the biggest challenges of the Earth’s complete freeze hypothesis is the question of how life survived the catastrophe,” said Thomas Jernan, a geologist at the University of Southampton. “Either it never happened or life somehow avoided wandering on the brink of extinction,” the scientist continues.
Jernan with an international team of geologists in a new study Published The scientific journal Nature Communications brings a surprising solution to an ancient mystery.
They confirmed the global snowfall
Geologists first studied the one-kilometer-thick formation located in southern Australia. 700 million years ago, it settled when this landmass was close to the equator.
However, instead of signs of a tropical climate, geologists have recognized clear evidence in the rocks of the existence and movement of glaciers. According to them, this is solid evidence that the Earth was covered by dense ice from pole to pole. For almost 50 million years.
But how stable is this icing?
To answer this question, researchers focused on so-called bound iron ores. These are rocks formed at the bottom of the ocean by replacing silicon-rich material and iron oxide-rich material.
“Iron sea water comes from hot springs. Under normal conditions, when atmospheric oxygen reaches the oceans, this iron oxidizes instantly and does not form bound iron ores,” explains Thomas Jernan.
During global icing, according to Kernan, the sea was cut off from access to the atmosphere, causing molten iron to accumulate. Eventually, it reached a high concentration, and after re-oxidation of the oceans, iron oxides were released from the water, forming whole layers.
“Bound iron ores show the presence of very different rock layers and cycles reminiscent of the climate cycles associated with the progress and retreat of glaciers,” said research associate author Rose Mitchell.
According to the researcher, such a variation is contrary to the expected conditions of a stable frozen planet.
“Frost resistance” times
A detailed view of the colonization cycles of bound iron ores led to a surprising discovery. They seem to be related to rotational changes in the Earth’s orbital parameters.
“Although the Earth’s climate system behaved very differently during global icing, changes in the Earth’s orbit ignored it and continued to do what they did before,” says Rose Mitchell.
Cyclical changes in the Earth’s orbit are considered by geologists to be one of the main factors driving the arrival of ice ages over the last three million years.
Quaternary glaciers correspond to periodic changes in the Earth’s orbit around the Sun (rotation lasts about 100,000 years), the Earth’s axis tilt (rotation lasts about 41,000 years) and its rotation (The so-called forecast, the cycle lasts about 23,000 years).
Can similar or similar cycles 700 million years ago achieve the exact opposite, i.e. can the occasional reversal of glaciers? According to British geologists, yes.
An oasis of life
This fact not only creates the rotation of specific rock layers, but also explains another fact. Survival of the fittest.
“Our findings are very important because we know today that complex biodiversity evolved and survived during this period of climate crisis, and so far we have not been able to explain how,” says Jernan. “In our study, ice-free oases formed in the ocean, which provided shelter for the first animals,” the scientist concludes.