Kenorland

Kenorland is a hypothetical supercontinent that may have been one of the earliest large landmasses on Earth. If it existed, it would have formed around 2.72 billion years ago during a time called the Neoarchaean Era. Scientists think Kenorland came together when several old pieces of land, known as cratons, joined up and new land formed.

The land that later became Laurentia – the core of today’s North America and Greenland – Baltica – today’s Scandinavia and Baltic region – Western Australia, and Kalaharia were all part of Kenorland. We know about Kenorland mostly by studying patterns in ancient rocks and volcanic formations.

Kenorland was named after the Kenoran orogeny, a long-ago period of mountain-building. This name itself comes from the town of Kenora in Ontario.

Formation

Kenorland was formed around 2.72 billion years ago through a series of events that added new land to Earth's surface. These events are shown in the greenstone belts of the Yilgarn craton, which include changed basalt rocks and granite areas that formed around the strong core of the Western Gneiss terrane. This core has parts that are even older, such as the Narryer Gneiss terrane.

Breakup or disassembly

Studies of Earth's magnetic past show that Kenorland stayed near the equator until movements in Earth's deep layers started around 2.48 billion to 2.45 billion years ago. During this time, big pieces of land began to drift apart. This breakup happened over many millions of years, between 2.48 and 2.10 billion years ago.

Scientists think this period marks when Earth started changing how landforms were made, moving from one way to another that involved the layers of Earth shifting. The land pieces known as Kola and Karelia began moving away from each other. By around 2.4 billion years ago, these lands were farther south. Another large land, Yilgarn (now part of Australia), was also moving on its own.

This breakup happened at the same time as a long period of cold climate, lasting up to 60 million years. During this time, lots of oxygen built up in the air, changing the planet's climate and leading to very cold temperatures worldwide. Even though there was less oxygen, tiny plants kept making food through photosynthesis, helping to balance the climate later on.