Panthalassa or Panthalassic Ocean (Sometimes called the Palae-Pacific or old Pacific Ocean)

Australia: The Land Where Time Began

Panthalassa or Panthalassic Ocean (Sometimes called the Palae-Pacific, palaeopacific or old Pacific Ocean)

This was an ocean that surrounded the supercontinent of Pangaea. It was comprised of the Pacific Ocean to the west and north of Pangaea and on the southeast side of Pangaea, the Tethys Ocean. When Pangaea fragmented the Tethys Ocean closed and the remainder of Panthalassa became the Pacific Ocean, the separating continental blocks forming the Indian, Atlantic and Arctic Oceans.

Most of the ocean plate from beneath Panthalassa has since been subducted under the North American and Eurasian Plates, the plate beneath the present-day Pacific has been formed since the breakup of Pangaea.

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