Pontus Tectonic Plate

• A long-lost tectonic plate called ‘Pontus’ has been rediscovered 20 million years after disappearing.
• The plate is known only from a few rock fragments from the mountains of Borneo and the ghostly remnants of its huge slab detected deep in Earth’s mantle.
• It was once a quarter of the size of the Pacific Ocean.
• Scientists have dubbed it the “Pontus plate” because at the time of its existence, it sat under an ocean known as the Pontus Ocean.
• Mechanism
  • Tectonic plates constantly move against one another, and the crust in oceanic plates is denser than continental plates, so oceanic plates get pushed under continental plates in a process called subduction and disappear.
  • Sometimes, however, rocks from a lost plate get incorporated into mountain-building events.
  • These remnants can point to the location and formation of ancient plates.

ABOUT TECTONIC PLATES

• Tectonic plates are large, rigid pieces of the Earth’s lithosphere, which is composed of the crust and uppermost mantle.
• They are typically composed of both continental and oceanic crust, and their thickness can vary from about 6 to 70 kilometers.
• There are primarily seven major tectonic plates: the African Plate, Antarctic Plate, Eurasian Plate, North American Plate, South American Plate, Pacific Plate, and Indo-Australian Plate.
• Additionally, there are several minor plates and microplates.