Siberian Traps

The Siberian Traps (Russian: Сибирские траппы, romanized: Sibirskiye trappy) are a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. They formed when huge amounts of basaltic lava burst out during a massive flood basalt event. This was one of the biggest volcanic eruptions in the last 500 million years, lasting for about two million years and ending around 251.9 million years ago.

Scientists think the Siberian Traps played a major role in causing the Permian–Triassic extinction event, the worst mass extinction in Earth's history. Many plants and animals, including most sea species, disappeared during this time. Later eruptions from the same area may have also caused smaller extinctions in the following millions of years.

Today, the Siberian Traps cover roughly 7 million square kilometers of Russia, with a volume of about 4 million cubic kilometers of solid rock. These ancient volcanic rocks give us important clues about Earth's past and how big natural events can change life on our planet.

Etymology

The word "trap" comes from an old Swedish word meaning "stairs." Geologists have used this term since the late 1700s to describe certain types of rock formations. In Siberia, these rocks form hills that look like steps, which is why they are called traps.

Formation

The Siberian Traps are a huge area of volcanic rock in Siberia, Russia. They were formed by a deep mantle plume that rose up and caused many volcanic eruptions. These eruptions happened mainly during the Permian and Triassic periods, spreading layers of basalt across the land.

The rocks in the Siberian Traps are mostly basalt, but they also contain other types of rock from many eruptions over about one million years. Below these traps lies a large basin filled with old layers of carbonate, evaporite, and coal-bearing rocks. When heated by the volcanic activity, these rocks can release harmful and greenhouse gases.

Effects on prehistoric life

Main article: Permian–Triassic extinction event

The Siberian Traps are linked to the Permian–Triassic extinction event, the worst mass extinction in Earth's history. The huge volcanic eruptions released gases like CO2 and SO2, which caused the climate to warm up quickly. This led to big changes in the oceans and on land, making it hard for many plants and animals to survive. Because of these changes, a large number of species disappeared, changing life on Earth forever. Scientists still discuss exactly why this extinction was so severe, but the eruptions from the Siberian Traps played a major role.

Dating

The volcanic eruptions that created the Siberian Traps sent out huge amounts of magma, leaving rocks behind that scientists can study today. One type of mineral found in these rocks is called zircon. Scientists used a special method called the CA-TIMS technique to figure out exactly how old the zircons are, which helps them understand when these huge eruptions happened.

Researchers also looked at other events that happened around the same time, like changes in sea level and meteor impacts. By studying rocks from the Siberian Traps and comparing them to rocks from other places, they found that most of the volcanic activity happened about 250 million years ago. This timing matches with a big event called the Permian–Triassic mass extinction, when many plants and animals died out.

Mineral deposits

The giant Norilsk–Talnakh nickel–copper–palladium deposit formed within the magma conduits in the Siberian Traps. Scientists have linked this deposit to the Permian–Triassic extinction event because large amounts of nickel and other elements were found in rock layers formed after the extinction. They compared the timeline of the volcanic activity in the traps with the timeline of the extinction to make this connection. Before this link was discovered, people thought the mass extinction and the volcanic activity happened around the same time because of similarities in the rocks' composition.