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 64 478 UPPER PLEISTOCENE 0.0 345.5 NO AGE GIVEN NO AGE GIVEN 0.01 0.7 0.355 DSDP INITIAL REPORTS