Abundant well preserved siliceous microfossils were finally encountered at 200 m below sea-floor (mbsf) down to 320 mbsf, after revealing no sign of preservation from the top of the cores at the sea-floor to 200 mbsf. The ages of sediments from 200 to 320 mbsf were determined with the microfossils as 44 million to 52 million years old (the Eocene Period). [See list of publications for more details.]
