Table
2. Diatom zonation and stratigraphic markers used during Leg 167.
Code
Zone and
Subzone
Category
Author
Base
Top
NPD12
Neodenticula
seminae
Interval
zone
Donahue
(1970)
LO
of Proboscia curvirostris
Present
NPD11
Proboscia
curvirostris
Interval
zone
Donahue
(1970)
LO
of Actinocyclus oculatus
LO
of Proboscia curvirostris
NPD10
Actinocyclus
oculatus
Interval
zone
Donahue
(1970)
LO
of Neodenticula koizumii
LO
of Actinocyclus oculatus
NPD9
Neodenticula
koizumii
Interval
zone
Koizumi
(1973b)
LO
of Neodenticula kamtschatica
LO
of Neodenticula koizumii
NPD8
N.
koizumii-N. kamtschatica
Concurrent
range zone
Koizumi
(1973b)
FO
of Neodenticula koizumii
LO
of Neodenticula kamtschatica
NPD7Bb
N.
kamtschatica-b
Interval
zone
Koizumi
(1973a, 1973b, 1985)
FO
of Thalassiosira oestrupii s.l.
FO
of Neodenticula koizumii
NPD7Ba
N.
kamtschatica-a
Interval
zone
Koizumi
(1973a, 1973b, 1985)
LCO
of Rouxia californica
FO
of Thalassiosira oestrupii s.l.
NPD7A
Rouxia
californica
Interval
zone
Akiba
(1986)
LCO
of Thalassionema schraderi
LCO
of Rouxia
californica
NPD6B
Thalassionema
schraderi
Interval
zone
Akiba
(1982b)
LCO
of Denticulopsis simonsenii
LCO
of Thalassionema schraderi
NPD6A
Denticulopsis
katayamae
Interval
zone
Maruyama
(1984b)
LO
of Denticulopsis dimorpha
LCO
of Denticulopsis simonsenii
NPD5D
D.
dimorpha
Taxon
range zone
Maruyama
(1984b), Akiba (1979)
FO
of Denticulopsis dimorpha
LO
of Denticulopsis dimorpha
NPD5C
Thalassiosira
yabei
Interval
zone
Maruyama
(1984b), Akiba (1979)
LCO
of Denticulopsis praedimorpha
FO
of Denticulopsis dimorpha
NPD5B
Denticulopsis
praedimorpha
Taxon
range zone
Akiba
et al. (1982a)
FO
of Denticulopsis praedimorpha
LCO
of Denticulopsis praedimorpha
NPD5A
Crucidenticula
nicobarica
Interval
zone
Akiba
et al. (1982a)
LCO
of Denticulopsis hyalina
FO
of Denticulopsis praedimorpha
NPD4Bb
Denticulopsis
hyalina-b
Interval
zone
Maruyama
(1984b)
FO
of Denticulopsis simonsenii
LCO
of Denticulopsis hyalina
NPD4Ba
Denticulopsis
hyalina-a
Interval
zone
Maruyama
(1984b)
FO
of Denticulopsis hyalina
FO
of Denticulopsis simonsenii
NPD4A
Denticulopsis
lauta
Lineage
zone
Koizumi
(1973b)
FO
of Denticulopsis lauta
FO
of Denticulopsis hyalina
NPD3B
Denticulopsis
praelauta
Lineage
zone
Akiba
(1983, 1986)
FO
of Denticulopsis praelauta
FO
of Denticulopsis lauta
NPD3A
Crucidenticula
kanayae
Interval
zone
Akiba
(1977)
FO
of Crucidenticula kanayae
FO
of Denticulopsis praelauta
NPD2B
Crucidenticula
sawamurae
Interval
zone
Gladenkov
and Barron (1995)
FO
of Crucidenticula sawamurae
FO
of Crucidenticula kanayae
NPD2A
Thalassiosira
fraga
Interval
zone
Barron
(1985a)
FO
of Thalassiosira fraga
FO
of Crucidenticula sawamurae
NPD1
Thalassiosira
praefraga
Interval
zone
Gladenkov
and Barron (1995)
FO
of Thalassiosira praefraga
FO
of Thalassiosira fraga
None
Rocella
gelida
Partial
range zone
Gladenkov
and Barron (1995)
FO
of Rocella gelida
FO
of Thalassiosira praefraga
Notes: Modified from Yanagisawa and Akiba, 1998. The boundary between Subzone NPD4Bb and Zone NPD5A can be also recognized by the FCO of Denticulopsis simonsenii. LO = last occurrence, FO = first occurrence, LCO = last common occurrence, FCO = first common occurrence.