Sea floor dating
One summary paper available on the project website says, The sediments are generally highly bioturbated.However, fine-scale lamination preserving alternations between millimeter scale laminae of biogenic and terrigenous material are also present at several of the drilled sites.In the 1940s and 1950s echo sounding was used to get a more detailed picture of the ocean floor.
There was also a lot less sediment on top than predicted. Early work on the ocean floor had been done by the Challenger expedition in the 1870s, using sounding techniques that involved seeing how far a rope with lead at the end would drop.One such crucial expedition was the Mid Pac expedition, which discovered the Mid-Pacific Mountain Range. If the Earth's surface was completely static, why had all the mountains on the continents not been worn away by weathering and filled up the oceans as sediment?This paradox is another on the list that was solved by plate tectonics.The Ridge extends into the South Atlantic Ocean between the South American and African Plates.The ocean ridge rises to between 2 to 3 km above the ocean floor, and has a rift valley at its crest marking the location at which the two plates are moving apart.
Long-age believers insist that hundreds of meters of sediment require at least hundreds of thousands of years to deposit.