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 29 280 A OLIGOCENE 38.0 91.5 NO AGE GIVEN NO AGE GIVEN 22.5 37.5 30 DSDP INITIAL REPORTS 29 280 A OLIGOCENE LOWER OLIGOCENE 91.5 101.0 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 22.5 37.5 30 DSDP INITIAL REPORTS 29 280 A LOWER OLIGOCENE UPPER EOCENE 101.0 177.0 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 30 43 36.5 DSDP INITIAL REPORTS 29 280 A UPPER EOCENE 196.0 224.5 NO AGE GIVEN NO AGE GIVEN 37.5 43 40.25 DSDP INITIAL REPORTS 29 280 A UPPER EOCENE MIDDLE EOCENE 234.0 385.5 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 37.5 49 43.25 DSDP INITIAL REPORTS 29 280 A MIDDLE EOCENE 385.5 519.0 NO AGE GIVEN NO AGE GIVEN 43 49 46 DSDP INITIAL REPORTS