Tertiary sediment from the East pacific rise.

More than 50 cores ranging in age from Pliocene to Lower Miocene have been recovered from the East Pacific Rise. Near the crestal regions the sediment cover is thin or lacking, and only Pleistocene sediments were recovered. On the flanks, the sediment thickness increases and pre-Pleistocene sediments are encountered. This pattern of increasing age and increasing sediment thickness away from the axis of the rise is in agreement with that predicted for spreading of the ocean floor.