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Table T9. Astronomically calibrated age estimates of calcareous nannofossil datums used as biostratigraphic tie points, Expedition 322. (See table notes.)

Nannofossil event Zone
Degree of
X medium Gephyrocapsa (>3.5 µm)–Emiliania huxleyi     0.082–0.063
FO Emiliania huxleyi NN21 B 0.291
LO Pseudoemiliania lacunosa NN20 A 0.436
LCO Reticulofenestra asanoi   A 0.905–0.901*
RE medium Gephyrocapsa (≥4 µm) +
FO Gephyrocapsa sp. 3 (G. parallela)
  A 1.04
FCO Reticulofenestra asanoi   D 1.136–1.078*
LO large Gephyrocapsa (>5.5 µm)   A 1.24
LO Helicosphaera sellii   C 1.34
FCO large Gephyrocapsa (>5.5 µm)     1.46
FO large Gephyrocapsa (>5.5 µm)   B 1.560–1.617*
LO Calcidiscus macintyrei (≥11 µm)   C 1.60
FO medium Gephyrocapsa (>3.5 µm)   A 1.67
LO Discoaster brouweri NN19 A 2.06
AB Discoaster triradiatus   A 2.135–2.216*
LO Discoaster pentaradiatus NN18 C 2.393–2.512*
LO Discoaster surculus NN17 C 2.52
LO Discoaster tamalis   C 2.87
LO Sphenolithus spp.   C 3.65
LO Reticulofenestra pseudoumbilicus (>7 µm) NN16 A 3.79
FCO Discoaster asymmetricus NN15–NN14 B 4.13
LO Amaurolithus primus     4.50
LO Ceratolithus acutus   B 5.04
FO Ceratolithus rugosus NN13 D 5.12
LO Triquetrorhabdulus rugosus     5.279*
FO Ceratolithus acutus   B 5.32
LO Discoaster quinqueramus NN12 A 5.59
LO Nicklithus amplificus   A 5.978–5.939*
FO Nicklithus amplificus   C 6.909–6.684*
PE Reticulofenestra pseudoumbilicus (>7 µm)   D 7.077–7.167*
FO Amaurolithus spp./Amaurolithus primus NN11b A 7.362–7.424*
FCO Discoaster surculus   B 7.88
LCO Minylitha convallis   D 7.78–8.3
FO Discoaster berggrenii NN11a D 8.52
PB Reticulofenestra pseudoumbilicus (>7 µm) NN10b A 8.785–8.761*
FO Discoaster pentaradiatus     9.1
FO Minylitha convallis   D 9.416
LO Discoaster hamatus NN10a C 9.560
LO Catinaster calyculus   D 9.674*
LO Catinaster coalitus   D 9.687*
X Discoaster hamatus–D. neohamatus     9.762*
FO Discoaster neohamatus   C 9.867–10.521*
LCO Discoaster exilis     10.427
FO Discoaster hamatus NN9 C 10.541
LO Coccolithus miopelagicus   C 10.613
FO Discoaster calcaris     10.676
FO Discoaster bellus gr.   C 10.72
FO Discoaster brouweri   A 10.734–10.764*
FO Catinaster calyculus   D 10.785*
FO Catinaster coalitus NN8 D 10.886–10.733*
LCO Discoaster kugleri   A 11.578–11.596*
FCO Discoaster kugleri NN7 B 11.863–11.905*
LO Cyclicargolithus floridanus   D 12.037
LO Coronocyclus nitescens     12.254
LCO Calcidiscus premacintyrei   A 12.447
FCO Triquetrorhabdulus rugosus     12.671
LCO Cyclicargolithus floridanus   A 13.294
LO Sphenolithus heteromorphus NN6 C 13.532–13.654*
LO Helicosphaera ampliaperta NN5   14.914*
AE Discoaster deflandrei     15.663*
FO Discoaster signus     15.702*
FCO Sphenolithus heteromorphus     17.721*
LCO Sphenolithus belemnos NN4   17.973*
LO Triquetrorhabdulus carinatus   D 18.315*
FO Sphenolithus belemnos NN3   18.921*
FO Helicosphaera ampliaperta     20.393*
X Helicosphaera euphratis–Helicosphaera carteri     20.894*
FCO Helicosphaera carteri     21.985*
LCO Triquetrorhabdulus carinatus     22.092
FO Sphenolithus disbelemnos   C 22.413
FO Discoaster druggii NN2 D 22.824*
LO Sphenolithus delphix   A 23.089
FO Sphenolithus delphix   A 23.356
LO Sphenolithus ciperoensis NN1 C 24.389

Notes: Datums are based on Pacific records if not otherwise stated. * = datums based on Atlantic or Mediterranean records. Age estimates adopted from Raffi et al. (2006). X = abundance crossover, FO = first occurrence, LO = last occurrence, LCO = last consistent occurrence, RE = reentrance, FCO = first consistent occurrence, AB = acme beginning, AE = acme end, PE = paracme end, PB = paracme beginning. Degree of reliability: A = distinct, well defined, and isochronous worldwide; B = indistinct and less well defined but reasonably isochronous; C = distinct and well defined but diachronous; D = indistinct, poorly defined, and diachronous. See Raffi et al. (2006) for detailed explanation.

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