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 66 489 QUATERNARY 0.0 5.5 NO AGE GIVEN NO AGE GIVEN 0 1.8 0.9 DSDP INITIAL REPORTS 66 489 LOWER MIOCENE 5.5 34.5 NO AGE GIVEN NO AGE GIVEN 16 22.5 19.25 DSDP INITIAL REPORTS