A new ocean basin is created when a tectonic
plate carrying a continent literally splits apart.
In this process the heat from underlying magma
wells up from deep within the earth, weakening
and stretching the overlying continental crust.
The brittle crust then fractures on each side
of the stressed area, allowing sections to drop.
The result is a rugged terrestrial rift valley.
early stage of ocean building is evident in several
parts of todays world, including the Baikal
region of southeastern Siberia known as the Basin,
and the United States from western Utah to eastern
California, an area known to geologists as the
Range. But the most dramatic example of an emerging
ocean basin in its infancy is the Great Rift Valley
of East Africa, stretching between Ethiopia and
As the continent of Africa breaks apart along
this 1,500 mile rift, a new plate (the Somali
Plate) is taking shape. In time, the sea will
invade the gap created by the separation, thus
forming a new ocean basin. The Red Sea is a widening
ocean basin located where the Arabian Peninsula
was severed from Africa long ago by the pulling
apart of the African Plate and Arabian Plate.
Africa is literally coming apart at the seams.
As a young ocean widens and matures, the undersea
rift develops a ridge of lava mountains on the
trailing edge of each plate. The Mid-Atlantic
Ridge, for example, rises where the American continents
are separating from Europe and Africa. Other Mid-Ocean
Ridges include the East Pacific Rise, several
hundred miles off the western coast of South America,
and the Indian Ridge, off the Eastern coast of
Africa, south of India. Each of these mid-ocean
ridges first appeared as a terrestrial rift valley
involved in the break-up of some ancient land
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