leg site hole age mnemonic auxiliary age mnemonic top of section depth(m) bottom of section depth(m) special condition age auxiliary age averaged age age top of section(million years) age bottom of section(million years) average age(million years)t data source 28 270 RECENT PLIOCENE 0.0 25.0 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 0 5 2.5 DSDP INITIAL REPORTS 28 270 LOWER MIOCENE 25.0 253.0 NO AGE GIVEN NO AGE GIVEN 16 22.5 19.25 DSDP INITIAL REPORTS 28 270 OLIGOCENE 253.0 395.5 NO AGE GIVEN NO AGE GIVEN 22.5 37.5 30 DSDP INITIAL REPORTS