Age Of Oldest Rocks On Ocean Floor

The data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins.

Age of oldest rocks on ocean floor.

Why are there no oceanic rocks older than 200 million years. There are rocks on every continent that are 3 to 4 billion years old. Contours of 20 million years are available as a layer that is currently set to invisible. These rocks turned out to be about 200 million years old only.

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. Examine the color code to understand how the age of rocks changes from the center to the edges of the ocean floor. The oldest ocean floor is located near the continents next to a subduction zone. As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.

The crust overlies the solidified and uppermost layer of the mantle the crust and the solid mantle layer together constitute oceanic lithosphere. This image shows the age of rocks on the atlantic ocean seafloor. The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age. In 1990 after 20 years of searching geologists found the oldest oceanic rocks by drilling into the seafloor of the western pacific.