The youngest sediments in the ocean are found at diverging plates, where new sediment is hardening. The further out from the diverging ridge, the older the sediment.
First, let's look at the words Ocean Floor and recall there are five Oceans and twenty-six Seas, which comprise the major bodies of water in the world. Let's remember also, that of the five oceans, one the Southern Ocean, possesses boundaries not very well defined and the question is, where does the Sea begin and end? Also, six of the seas are enclosed or almost enclosed and twenty of the seas are coastal seas, which means they are bordered by land boundaries. Now, of all of these bodies of water, which one is the oldest ocean floor? Which one has the oldest rock?
Now, I will tell you there are really more than seventy oceans and seas in the world,which include the straits, gulfs and bights. Which one all these oceans/seas has the oldest floor? Which one has the oldest rock? My point of course is that not all of the oceans and seas have been studied by scientists in a search for the one, and only oldest floor and oldest rock. And, truthfully no one really knows the exact answer to these questions at this time.
Now, go to this website and read about the earth and the oceans and seas of earth at Oceanography: Oceans. www.seafriends.org.nz/oceano
For every science, there must be a unifying theory in order for science to make progress, in scientific study. For instance in biology the unifying theory is the theories of evolution and genetics. In Physics the unifying theory is the theories of motion and gravitation. In chemistry there is the unifying model of atomic theory and in geology we find the theory model is plate tectonics. So, what is the unifying theory found in the scienticfic study of oceans and seas? It is the global theory of plate tectonics.
In the 1960's the invention of the Echosounder made it possible to get some idea of where the ocean/sea floor lies. By using the Echosounder one of the most notable finds was the mid-ocean ridge system, which until then no one knew was actually, taller than most of the continental mountains, and it rises only two or three kilometers above the ocean floor and maybe more. The ocean floor is filled with sea trenches, undersea volcanoes and very large areas of abyssal plains. These discoveries led to the unifying theory, the theory of global plate tectonics as the unifying theory in the study of the oceans/seas.
It is dark and cold on the ocean/sea floor and although man has walked on the moon, no one has nor, can he ever walk on the floor of the ocean/sea in the same manner as man has walked on the moon. The atmospheric pressure would crush his body in seconds is the theory we know of today. Go to the Website, Geology.Geophysics 101, The Sea Floor at www.honolulu.hawaii.edu/distance/gg101/html
Among the oldest rocks from the Ocean/sea floor is the Dongwanzi Ophilolite, which is about 3 miles (5km) wide, about 30 miles(50km) long and 9 miles (14km) thick. It was found in May 2000 in a mountainous region of Eastern Hebei province, near the inner border of Mongolia and about 155 miles(250km) from Beijing. Actually, very close the Great Wall of China, and is belived to be 2.505 billion years old, which places it in the Archean period of the earth. There are some rocks, which have been found, and some may be older than the Ophilolite, however none of them are as large as this particular rock.
Now, based on where the rock was found what ocean/sea do you think it came from? Is it the Yellow Sea or the North China Sea? Look at a Map of China and see the distance from Mongolia to Beijing and the sea. If, you enter the words, Ocean floor rock into your web browser and click, you will find lots of sites with more information. And, it is really interesting material. Enjoy!