Formed over a billion years ago from ancient ocean sediments, they are among the oldest in the United States.
These rocks were created from ancient ocean sediments nearly one billion years ago.
It's made of an imperishable ceramic substance which repels even ocean sediment.
They originated from ocean sediments deposited between 400 million and 1 billion years ago.
The authors examined deep ocean sediments from a site that was off the west coast of the supercontinent at the time.
This rock, like other formations throughout the Appalachian region, was formed from ancient ocean sediments nearly one billion years ago.
The widespread sea ice prevents the deposition of fresh carbonates in ocean sediment.
In addition the Thresher is being covered by ocean sediment, which may in time provide a further means of containment.
Not only is land a major source of the ocean sediments, but organisms living within the ocean contribute, as well.
The ridge is defined by local geographic boundaries and an uplift of ocean sediment.