|
Code
|
Zone/Subzone
|
Category
|
Reference
|
Base
|
Top
|
|---|---|---|---|---|---|
| NPD12 | Neodenticula seminae | Interval zone | Donahue (1970) | LO Proboscia curvirostris | Present |
| NPD11 | Proboscia curvirostris | Interval zone | Donahue (1970) | LO Actinocyclus oculatus | LO Proboscia curvirostris |
| NPD10 | Actinocyclus oculatus | Interval zone | Donahue (1970) | LO Neodenticula koizumii | LO Actinocyclus oculatus |
| NPD9 | Neodenticula koizumii | Interval zone | Koizumi (1973a) | LCsO Neodenticula kamtschatica | LO Neodenticula koizumii |
| NPD8 | N. koizumii-N. kamtschatica | Concurrent range zone | Koizumi (1973a) | FO Neodenticula koizumii | LCsO Neodenticula kamtschatica |
| NPD7Bb | N. kamtschatica-b | Interval zone | Koizumi (1973a, 1973b, 1985) | FO Thalassiosira "oestrupii" s. ampl. | FO Neodenticula koizumii |
| NPD7Ba | N. kamtschatica-a | Interval zone | Koizumi (1973a, 1973b, 1985) | FCsO Neodenticula kamtschatica | FO Thalassiosira "oestrupii" s. ampl. |
| NPD7A | Rouxia californica | Interval zone | Akiba (1986) | LCO Thalassionema schraderi | FCsO Neodenticula kamtschatica |
| NPD6B | Thalassionema schraderi | Interval zone | Akiba (1982a) | LCsO Denticulopsis simonsenii | LCO Thalassionema schraderi |
| NPD6A | Denticulopsis katayamae | Interval zone | Maruyama (1984b) | LO Denticulopsis dimorpha | LCsO Denticulopsis simonsenii |
| NPD5D | Denticulopsis dimorpha | Taxon range zone | Maruyama (1984b), Akiba (1979) | FO Denticulopsis dimorpha | LO Denticulopsis dimorpha |
| NPD5C | Thalassiosira yabei | Interval zone | Maruyama (1984b), Akiba (1979) | LCO Denticulopsis praedimorpha | FO Denticulopsis dimorpha |
| NPD5B | Denticulopsis praedimorpha | Taxon range zone | Akiba et al. (1982b) | FO Denticulopsis praedimorpha | LCO Denticulopsis praedimorpha |
| NPD5A | Crucidenticula nicobarica | Interval zone | Akiba et al. (1982b) | FCO Denticulopsis simonsenii | FO Denticulopsis praedimorpha |
| NPD4Bb | Denticulopsis hyalina-b | Interval zone | Maruyama (1984b) | FO Denticulopsis simonsenii | FCO Denticulopsis simonsenii |
| NPD4Ba | Denticulopsis hyalina-a | Interval zone | Maruyama (1984b) | FO Denticulopsis hyalina | FO Denticulopsis simonsenii |
| NPD4A | Denticulopsis lauta | Lineage zone | Koizumi (1973a) | FO Denticulopsis lauta | FO Denticulopsis hyalina |
| NPD3B | Denticulopsis praelauta | Lineage zone | Akiba (1983, 1986) | FO Denticulopsis praelauta | FO Denticulopsis lauta |
| NPD3A | Crucidenticula kanayae | Interval zone | Akiba (1977) | FO Crucidenticula kanayae | FO Denticulopsis praelauta |
| NPD2B | Crucidenticula sawamurae | Interval zone | Gladenkov and Barron (1995) | FO Crucidenticula sawamurae | FO Crucidenticula kanayae |
| NPD2A | Thalassiosira fraga | Interval zone | Barron (1985a) | FO Thalassiosira fraga | FO Crucidenticula sawamurae |
| NPD1 | Thalassiosira praefraga | Interval zone | Gladenkov and Barron (1995) | FO Thalassiosira praefraga | FO Thalassiosira fraga |
| None | Rocella gelida | Partial range zone | Gladenkov and Barron (1995) | FO Rocella gelida | FO Thalassiosira praefraga |
Notes: Modified from Maruyama, 2000. The boundary between Subzone NPD4Bb and Zone NPD5A can be also recognized by the LCO Denticulopsis hyalina. FO = first occurrence, LO = last occurrence, FCO = first common occurrence, LCO = last common occurrence, FCsO = first consistent occurrence, LCsO = last consistent occurrence.