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 29 283 A MIDDLE PLEISTOCENE UPPER PLIOCENE 1.5 12.5 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 0.8 3.4 2.1 DSDP INITIAL REPORTS 29 283 A PLIOCENE MIOCENE 12.5 20.5 NO AGE GIVEN NO AGE GIVEN NO AGE GIVEN 1.8 22.5 12.15 DSDP INITIAL REPORTS