Sturtian glaciation

The Sturtian glaciation, also known as the Sturt glaciation, was a time when huge parts of Earth were covered in ice. This happened during the Cryogenian Period, long before humans or even dinosaurs existed. Scientists think it lasted from about 717 million years ago to 660 million years ago, which is a very long time—about 57 million years.

During this period, Earth might have become a "Snowball Earth," meaning almost the whole planet was frozen over. Some scientists believe it was one big icy event, while others think it was many smaller icy times in different places. Either way, the Sturtian glaciation was one of the longest and most serious periods of ice in Earth's history, as we can see from the geologic record. It came after an even earlier time of ice called the Huronian glaciation. This event helps us understand how Earth’s climate has changed over millions of years.

Etymology of name

The term "Sturtian glaciation" comes from the Sturt Formation, a group of rocks found in the Adelaide Superbasin in South Australia. This formation is named after Sturt Gorge, which itself is named for the Sturt River. The river was named in 1831 after explorer Charles Sturt.

The Sturtian glaciation refers to one of two big ice ages that happened long ago on Earth during the Cryogenian Period. It was first studied by scientists Douglas Mawson and Reg Sprigg in 1950. Their work helped scientists understand ancient ice ages and led to important ideas about Earth's climate history.

Timeline

The Sturtian glaciation is believed to have lasted from about 717 million years ago to around 660 million years ago, covering a period of roughly 57 million years. This was a time when large parts of Earth were covered in ice.

Geology

Rocks that show evidence of the Sturtian Glaciation have been found on every continent, including Australia, Canada, China, Ethiopia, Namibia, Siberia, and Svalbard. These rocks include special layers called diamictite and mudstone, which tell us about how the glaciers moved forward and then melted back.

Scientists think that the very cold temperatures during this time were caused by low amounts of CO₂ in the air, linked to the breaking apart of a huge ancient landmass called Rodinia. The glaciers began to grow and cover large areas in less than a million years.

Effects on life

After the Sturtian glaciation, signs from ancient life show that living things became more complex. Scientists found special markers and fossils that tell us life on Earth was changing and growing in new ways during this time.