The red rocks lying there can give us the answer.
The Earth is warming, but between 720 and 635 million years ago, a consensus theory suggested that the Earth had experienced two ice ages with snow and ice covering most of the surface. Scientists call this the Snowball Earth phase, roughly translated as Snow Globe.
The ice age was very fast, within a few thousand years, the continent as well as the sea surface from the North to the South were covered with thick ice. Life on Earth at that time (if any) had to “take refuge” in the sea, separate from both sunlight and atmosphere of the Earth.
The Snow Globe phase has caused science to ask again: how does life rise from the thick ice?
Globalization may cause a major genocide, but life can still find a way out; we are sitting here is the proof that life does not succumb to ice. In a study published late last year, the team of scientists said they had discovered a factor that most likely saved Earth’s life: oases hidden beneath ancient ice.
Half a billion years ago, the planet Earth Snow stopped abruptly, but its footprint is still present in sedimentary layers around the world. To reach the site of these ancient traces, sedans Max Lechte and Malcolm Wallace drove a 15-hour drive to a remote location in South Australia. In 2015, two scientists had to walk in the 50 degree Celsius sunshine to reach the archaeological site. Professor Wallace’s shoe soles melted under the ground heat, he fixed it with a little duct tape and moved on.
Dark red rock formations formed in the seabed at the time the ground froze, and it was that brilliant color that attracted Professor Lechte’s attention; He collected some rock samples to study. In 2015 and 2016, he traveled to Namibia and Death Valley, California to find more red rocks, forming the same period as those found in South Australia.
Red indicates that the rock is rich in iron, and the resulting red color is due to iron rusting when exposed to oxygen in the air. We know oxygen is one of the key factors that allow life to exist, and rust proves that oxygen is present in seawater. From there, it is inferred that the sea will rust the iron-containing rocks that will support the life of marine life.
“This is the first direct evidence that the oxygen-rich marine environment during the Snow Globe era,” said Professor Lechte.
But scientists still don’t know how oxygen is mixed with seawater. It is true that the atmosphere was rich in oxygen at the time, but the thick layer of ice prevented the oceans from making much contact with the atmosphere, and life could not have survived until most of the ice melted.
“[The ice] will make the sea lack of oxygen, which should kill the creatures that need oxygen to live. This is still a question we cannot explain, ”said Professor Lechte.
In labs located in the US and China, the team crushed iron-rich rocks, mixed them with acids to measure the amount of iron isotopes in ancient rock samples. They found that offshore rocks were less rusty than nearshore rocks.
Today, under the thick ice of Antarctica, the flow of water from the glaciers is melting into one with the Southern Ocean. Water melting from ice can contain oxygen bubbles and is most likely a source of oxygen that feeds marine life.
Paul Hoffman, a biologist from Harvard and a pioneer of research that supports the Snow Planet hypothesis, thinks the new research results are based on solid evidence, and that it matches the findings. His plan for Earth during the ice age.
However, Professor Hoffman added that it is still not possible to confirm that the melting water from the ice is the main source of oxygen for marine life.
“From a hypothetical perspective, we still don’t have enough data to show how life on Earth overcomes the challenges of the Snow Globe,” said Hoffman.