Table 3. Nannofossil datums, absolute ages, and depths at Site 998. Notes: T = top of species range (last appearance datum), B = base of species range (first appearance datum). Event Zone (base) Age (Ma) Core, section, interval (cm) Depth (mbsf) Hole 998A: B Emiliania huxleyi CN15 0.248 1H-CC to 2H-1, 100 9.30 T Pseudoemiliania lacunosa CN14b 0.408 2H-1, 100 to 2H-2, 100 10.55 T Reticulofenestra asanoi 0.88 3H-3, 100 to 3H-4, 100 23.05 B Gephyrocapsa parallela CN14a 0.94 3H-5, 100 to 3H-6, 100 26.05 B Reticulofenestra asanoi 1.17 3H-5, 100 to 3H-6, 100 26.05 T Large Gephyrocapsa spp. 1.23 3H-CC to 4H-1, 100 28.40 T Helicosphaera sellii 1.26 3H-CC to 4H-1, 100 28.40 B Large Gephyrocapsa spp. 1.48 4H-1, 100 to 4H-2, 100 29.55 T Calcidiscus macintyrei 1.64 4H-4, 100 to 4H-5, 100 34.05 B Gephyrocapsa caribbeanica CN13b 1.71 4H-5, 100 to 4H-6, 100 35.55 T Discoaster brouweri CN13a 1.95 4H-6, 100 to 4H-7, 60 36.85 T Discoaster pentaradiatus CN12d 2.36 4H-6, 100 to 4H-7, 60 36.85 T Discoaster surculus CN12c 2.51 6H-4, 100 to 6H-5, 100 53.05 T Discoaster tamalis CN12b 2.82 7H-3, 100 to 7H-4, 100 61.05 T Sphenolithus spp. CN12a 3.62 8H-2, 100 to 8H-3, 100 69.05 T R. pseudoumbilicus CN12a 3.83 8H-7, 60 to 8H-CC 75.50 T Amaurolithus spp. CN11 4.50 10H-6, 100 to 10H-CC 93.94 B Ceratolithus rugosus CN10c 5.046 10H-CC to 11H-1, 100 94.94 B Ceratolithus acutus CN10b 5.089 11H-4, 100 to 11H-5, 100 100.55 T Discoaster quinqueramus CN10a 5.537 11H-CC to 12H-1, 100 104.47 B Amaurolithus spp. CN9b 7.392 13H-2, 100 to 13H-3, 100 116.55 B Discoaster berggrenii CN9a 8.281 14H-2, 100 to 14H-3, 100 126.05 T Discoaster hamatus CN8a 9.635 15H-4, 100 to 15H-5, 100 138.55 B Discoaster hamatus CN7 10.476 16H-5, 100 to 16H-6, 100 149.58 B Catinaster coalitus CN6 10.794 16H-CC to 17H-1, 100 152.12 T Cyclicargolithus floridanus 13.2 18X-2, 100 to 18X-3, 100 164.05 T Sphenolithus heteromorphus CN5a 13.523 18X-3, 100 to 18X-4, 100 165.55 B Sphenolithus heteromorphus CN3 18.2 26X-CC to 27X-1, 100 242.56 T Sphenolithus belemnos 18.3 27X-1, 100 to 27X-2, 100 244.95 B Sphenolithus belemnos CN2 19.2 28X-3, 100 to 28X-4, 100 257.65 T Sphenolithus delphix 23.8 35X-CC to 36X-1, 100 330.01 T Dictyococcites bisectus CN1c 23.9 36X-2, 100 to 36X-3, 100 333.05 T Sphenolithus ciperoensis CN1a 25.5 40X-2, 100 to 40X-3, 100 371.45 T Sphenolithus distentus CP19b 27.5 48X-2, 100 to 48X-3, 68 448.39 B Sphenolithus ciperoensis CP19a 29.9 52X-2, 103 to 52X-3, 103 486.98 B Sphenolithus distentus CP18 31.5 55X-1, 100 to 55X-2, 100 514.25 T Reticulofenestra umbilicus CP17 32.3 60X-4, 100 to 60X-5, 100 566.95 T Ericsonia formosa CP16c 32.8 61X-4, 100 to 61X-5, 100 576.55 T Discoaster saipanensis CP16a 34.2 62X-4, 100 to 62X-5, 60 586.00 T Discoaster barbadiensis CP16a 34.3 62X-4, 100 to 62X-5, 60 586.00 T Chiasmolithus grandis CP15 37.1 Below base of section Hole 998B: T Reticulofenestra umbilicus CP17 32.3 1R-5, 100 to 1R-6, 90 566.00 T Ericsonia formosa CP16c 32.8 2R-3, 100 to 2R-4, 110 572.70 T Discoaster saipanensis CP16a 34.2 4R-3, 110 to 4R-4, 110 591.95 T Discoaster barbadiensis CP16a 34.3 4R-3, 110 to 4R-4, 110 591.95 T Chiasmolithus grandis CP15 37.1 10R-5, 110 to 10R-4, 100 651.10 B Reticulofenestra bisecta 38.0 13R-4, 110 to 13R-CC 680.24 T Chiasmolithus solitus CP14b 40.4 13R-3, 110 to 13R-4, 110 678.65 T Nannotetrina fulgens 43.1 19R-CC to 20R-1, 126 741.62 B Reticulofenestra umbilicus CP14a 43.7 20R-CC to 21R-1, 110 749.07 T Chiasmolithus gigas CP13c 44.5 25R-1, 100 to 25R-2, 100 781.55 B Chiasmolithus gigas CP13b 46.1 28R-1, 125 to 28R-2, 120 810.48 B Nannotetrina fulgens CP13a 47.3 30R-2, 129 to 30R-3, 92 831.16 B Discoaster sublodoensis CP12 49.7 32R-6, 90 to 32R-CC 855.43 T Tribrachiatus orthostylus 50.6 33R-1, 123 to 33R-3, 100 859.20 B Discoaster lodoensis CP10 52.0 Below base of section