Age Of Oldest Rocks On Ocean Floor

The oldest ocean floor is located near the continents next to a subduction zone.

Age of oldest rocks on ocean floor.

Contours of 20 million years are available as a layer that is currently set to invisible. In 1990 after 20 years of searching geologists found the oldest oceanic rocks by drilling into the seafloor of the western pacific. As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock. The data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins.

There are rocks on every continent that are 3 to 4 billion years old. The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age. Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch. 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.

Consider how the age of rocks is related to the shape of the seafloor you saw in step 3. This dataset shows the age of the ocean floor along with the labeled tectonic plates and boundaries. The crust overlies the solidified and uppermost layer of the mantle the crust and the solid mantle layer together constitute oceanic lithosphere. Why are there no oceanic rocks older than 200 million years.