The Atlantic Ocean’s story is intricately tied to the movements of the Earth’s lithospheric plates and the history of supercontinents. Evidence from both the fossil and geological records indicates that Earth’s continental plates have merged into supercontinents multiple times since the Archean era, with Pangea being the most recent and well-known. Formed around 300 million years ago, Pangea began to rift apart about 100 million years later due to internal forces and massive volcanic eruptions linked to large-scale mantle upwelling.
This breakup, a globally significant event, coincided with the catastrophic End Triassic mass extinction. The rift zone created in the Pangean crust led to the separation of the North American and African plates, as well as the South American and African plates, and the North American and Eurasian plates. This separation gave rise to a deep basin that allowed ocean waters to flow in, marking the birth of the Atlantic Ocean.
The mantle plume that initiated Pangea’s breakup produced vast volumes of volcanic rock, creating a new mountain belt within the widening basin between the American and African/Eurasian plates. This area became known as the mid-Atlantic ridge, a divergent plate boundary extending north-south, continually producing new oceanic plate volcanic rocks. This ridge is part of the largest mountain chain on Earth, stretching from near Iceland in the north to near Antarctica in the south.
For much of human history, these volcanically active mountains remained a mystery. It was only with the advent of modern seafaring technology, such as sonar, in the mid-20th century that the seafloor was mapped, revealing these mountains and leading to a comprehensive understanding of plate tectonics. The Atlantic Ocean’s formation is a testament to the dynamic nature of Earth’s crust and the powerful forces that continue to shape our planet.
