Kenorland

Kenorland is a hypothetical supercontinent that may have been one of the earliest big land areas on Earth. If it existed, it would have formed about 2.72 billion years ago.

Scientists think Kenorland formed when several old pieces of land, called cratons, joined together.

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 learn about Kenorland by studying very old rocks and volcanic formations.

Kenorland was named after the Kenoran orogeny, a time long ago when mountains were built. The name comes from the town of Kenora in Ontario.

Formation

Kenorland was formed about 2.72 billion years ago. It grew as new land added to Earth. You can see signs of this in the greenstone belts of the Yilgarn craton. These belts have changed basalt rocks and granite areas. They formed around a strong core called the Western Gneiss terrane. This core has even older parts, like 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. 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. Tiny plants kept making food through photosynthesis, helping to balance the climate later on.