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 6 52 NEOGENE 0.0 27.4 NO AGE GIVEN NO AGE GIVEN 1.8 22.5 12.15 DSDP INITIAL REPORTS 6 52 TERTIARY 28.0 57.9 NO AGE GIVEN NO AGE GIVEN 1.8 65 33.4 DSDP INITIAL REPORTS 6 52 CRETACEOUS 57.9 68.9 NO AGE GIVEN NO AGE GIVEN 65 135 100 DSDP INITIAL REPORTS