The central sub-basin, which is also known as Great Meteor East after a seamount situated to the west, occupies a broad area of 57,187 km2 (22,080 sq mi) and is bounded by about the 5,400 meters (17,700 ft)-contour.
[1][2][3] In 1980, the Nuclear Energy Agency's Seabed Working Group selected the Madeira Abyssal Plain as a site for the possible disposal of heat-emitting radioactive waste.
[5][6] An average of 1.1 kilometers (0.68 mi) of exclusively deep-sea sediments, resting upon oceanic crust, underlies the Madeira Abyssal Plain.
Seismic reflection profiles across the Canary Basin and Madeira Abyssal Plain reveal north-northeast – south-southwest ridge and trough terrain typical of oceanic crust and west-northwest – east-southeast striking fracture zone valleys that are spaced about 100 kilometers (62 mi) part.
Because most of the Madeira Abyssal Plain lies within the Cretaceous Superchron, the oceanic crust underlying it cannot be precisely dated by magnetic striping.
However, interpolation between recognised magnetic stripes estimated an age range of about 75 to 105 Ma for the oceanic crust underlying the central sub-basin.
In seismic reflection, the sequence of turbidites varies from being strongly acoustically laminated near the top to poorly stratified to transparent near the base.
As determined by microfossils, each individual layer often represents several tens of thousands of years of pelagic sedimentation in a deep sea, abyssal environment.
During the last 2.6 million years within the region of the Madeira Abyssal Plain, carbonate compensation depth has been closely controlled by the general circulation of ocean currents and has oscillated in phase with climatic shifts.