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 68 501 UPPER PLEISTOCENE 0.0 7.6 NO AGE GIVEN NO AGE GIVEN 0.01 0.7 0.355 DSDP INITIAL REPORTS 68 501 LOWER PLEISTOCENE 55.1 64.6 NO AGE GIVEN NO AGE GIVEN 1.2 1.8 1.5 DSDP INITIAL REPORTS 68 501 UPPER MIOCENE 226.1 264.1 NO AGE GIVEN NO AGE GIVEN 5 10.5 7.75 DSDP INITIAL REPORTS