sentences:  The sediments drilled at ODP site 1149 are about 400 m thick and are as old as 134 million years.The sedimentary section is a typical pelagic stratigraphy, accumulated mostly in the Cretaceous but also in the last 7 million years (late Neogene) built on a basement of Early Cretaceous oceanic crust.The lowermost portion is carbonate and chert, the next layer is very chert-rich, the third layer is clay-rich.