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Table T3. Age assignments of biostratigraphic diatom zones used during Leg 177.

Zone Reference Top
(Ma)
Base
(Ma)
Thalassiosira lentiginosa Subzone c 1 0.00 0.18
Thalassiosira lentiginosa Subzone b 1 0.18 0.42
Thalassiosira lentiginosa Subzone a 1 0.42 0.65
Actinocyclus ingens Subzone c 1 0.65 1.07
Actinocyclus ingens Subzone b 1 1.07 1.30
Actinocyclus ingens Subzone a 1 1.30 1.80
Proboscia barboi 1 1.77 2.00
Thalassiosira kolbei/Fragilariopsis matuyamae 1 2.00 2.50
Thalassiosira vulnifica 1 2.50 2.63
Thalassiosira insigna* 2 2.63 3.26
Fragilariopsis interfrigidaria 2 3.26 3.80
Fragilariopsis barronii 2 3.80 4.44
Thalassiosira inura 2 4.44 4.92
Thalassiosira oestrupii 2 4.92 5.56
Fragilariopsis reinholdii* 2 5.56 8.10
Actinocyclus ingens var. ovalis 2 8.10 8.68
Thalassiosira torokina 2 8.68 9.01
Asteromphalus kennettii 2 9.01 10.23
Denticulopsis hustedtii 2 10.23 10.63
Denticulopsis dimorpha 2 10.63 11.67
Denticulopsis dimorpha/Nitzschia denticuloides 2 11.67 12.20
Denticulopsis praedimorpha 2 12.20 12.84
Nitzschia denticuloides 2 12.84 13.51
Denticulopsis hustedtii/Nitzschia grossepunctata 2 13.51 14.17
Actinocyclus ingens var. nodus 2 14.17 14.38
Nitzschia grossepunctata 2 14.38 15.38
A. ingens/D. maccollumii 2 15.38 16.20
Denticulopsis maccollumii 2 16.20 16.75
Crucidenticula kanayae 2 16.75 17.72
Thalassiosira fraga 2 17.72 20.79
Thalassiosira spumellaroides 2 20.79 22.58
Rocella gelida 2 22.58 26.50
Lisitzinia ornata 2 26.50 27.95
Azpeitia gombosii 2 27.95 28.35
Rocella vigilans 2 28.35 30.24
Cavitatus jouseanus 2 30.24 30.62
Rhizosolenia gravida/oligocaenica 2 30.62 33.22

Notes: * = revised zones. References: 1 = Gersonde and Bárcena (1998), 2 = Gersonde et al. (1998).

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