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 4 27 CENOZOIC 0.0 235.0 NO AGE GIVEN NO AGE GIVEN 0 65 32.5 DSDP INITIAL REPORTS 4 27 LOWER MIOCENE 235.0 254.0 NO AGE GIVEN NO AGE GIVEN 16 22.5 19.25 DSDP INITIAL REPORTS 4 27 UPPER OLIGOCENE 369.0 378.0 NO AGE GIVEN NO AGE GIVEN 22.5 30 26.25 DSDP INITIAL REPORTS 4 27 UPPER EOCENE 454.0 475.0 NO AGE GIVEN NO AGE GIVEN 37.5 43 40.25 DSDP INITIAL REPORTS