Oldest Ocean Floor Subduction

Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate it is composed of the upper oceanic crust with pillow lavas and a dike complex and the lower oceanic crust composed of troctolite gabbro and ultramafic cumulates.

Oldest ocean floor subduction. Because of this correlation between age and subduction potential very little ocean floor is older than 125 million years and almost none of it is older than 200 million years. Although oceanic crust has been forming on earth for over 4. It is for this reason that the oldest segment of ocean floor found in the far western pacific is apparently only about 200 million years old even though the age of earth is. Check answer oceanic crust is eventually destroyed in subduction zones.

Although oceanic crust has been forming on earth for over 4. There are rocks on every continent that are 3 to 4 billion years old. The oldest ocean floor is located near the continents next to a subduction zone. Why are there no oceanic rocks older than 200 million years.

For that geologists date and study continental crust. It took exploration of the ocean floor to discover sea floor spreading the mechanism for the movement of continents that alfred wegener lacked. There are rocks on every continent that are 3 to 4 billion years old. Thus for each segment of new ocean floor created at the ridges an equal amount of old oceanic crust is destroyed at the trenches or so called subduction zones.

The crust overlies the solidified and uppermost layer of the mantle the crust and the solid mantle layer together constitute oceanic lithosphere. Oceanic crust is eventually destroyed in subduction zones. Why are there no oceanic rocks older than 200 million years.