PONTUS TECTONIC PLATE (Syllabus: GS Paper 1– Geography)

News-CRUX-10     14th October 2023        

Context: A long-lost tectonic plate dubbed 'Pontus' was recently discovered by chance by scientists studying ancient rocks in Borneo.


Pontus Tectonic Plate

  • About: The Pontus Tectonic Plate, a long-lost tectonic plate, was recently found in the western Pacific Ocean.
  • Vast Size: This massive plate was once approximately 15 million square miles in size, accounting for about one-quarter of the Pacific Ocean.
  • Ancient Origins: It has an extensive history, dating back as far as 160 million years and more recently to around 20 million years ago.
  • Subduction and Loss: Over millions of years, the Pontus Plate was gradually subducted and pulled beneath a neighboring plate by the force of gravity.


Discovery Process

  • Gravity-Driven Subduction: The denser nature of the subducting plate compared to the surrounding mantle results in it being pulled down into the Earth's mantle.
  • Residual Traces: When a plate subducts, it leaves behind rock fragments concealed within mountain belts.
  • Scraped Upper Layers: During subduction, upper sections of the subducting plate can be scraped off.



Tectonic Plate

  • A tectonic plate, also known as a lithospheric plate, is a substantial, irregularly shaped slab of solid rock, typically composed of both continental and oceanic lithosphere.
  • Diverse Sizes: These plates can vary significantly in size, ranging from a few hundred to thousands of kilometers across, with the Pacific and Antarctic Plates among the largest.