JRY-IODP359-LM013.JPG
JRY-IODP359-LM012.JPG
JRY-IODP359-LM014.JPG
JRY-IODP359-LM015.JPG
JRY-IODP359-LM016.JPG
JRY-IODP359-LM017.JPG
Matsuoka Okada 1989 pl1-01.JPG
Matsuoka Okada 1989 pl1-03.JPG
Matsuoka Okada 1989 pl1-12.JPG
Matsuoka Okada 1989 pl1-14.JPG
Matsuoka Okada1990 pl2-07.JPG
Matsuoka Okada1990 pl2-08.JPG
Matsuoka Okada1990 pl2-09.JPG
Matsuoka Okada1990 pl2-10.JPG
Matsuoka Okada1990 pl2-11.JPG
Rio1982 pl2 11-12.JPG
Rio1982 pl2 4-10.JPG
Rio1982 pl4-7.JPGTaxonomy:
NB The name G. caribbeanica has also been applied to this morphtype by, for example, Pujos-Lamy (1977), Samtleben (1980), Perch-Nielsen (1985). In modern usage however, the name is normally only applied to the Late Quaternary form.
Distinguishing features: Large Gephyrocapsa species; bridge at intermediate angle (40-60°) to the short axis, central opening size moderate to narrow.
Farinacci & Howe catalog pages: Gephyrocapsa lumina * ,
Morphology remarks: As noted by Bukry (1973) the bridge is rather narrow, and so it is susceptible to being lost by dissolution [my obs - JRYoung 2016].
The larger forms are the most distinctive, but intergrade into smaller specimens with more open central areas.
Size: Coccolith length 5.5 - 7µm. (the minimum length of 5.5µm is a rather artificial cut-off but useful for biostratigraphy, see e.g. Raffi et al. 2006).
| Tags | LITHS: placolith, elliptical, CA: bridge, bridge-diagonal, grill, CSPH: spherical, monomorphic, V-UNITS: none, R-UNITS: all, c-str, distal shield, prox shield, tube, DETAILS: ca_conjunct, isogyres kinked, isogyres oblique, rim-unicyclic, |
| Metrics | Lith size: 5->7µm; Sources: |
See also: Gephyrocapsa caribbeanica - this is a somewhat similar Late Quaternary species but it has a more closed central area and the bridge is nearly flush with the shield rather than elevated above it, as is the case in G. lumina.;
Geological Range:
Notes: Early Pleistocene, LAD marks base of the small Gephyrocapsa zone. The FAD is also used in some schemes (e.g. as FAD Gephyrocapsa >5.5µm) although this is a gradational event which is harder to place consistently. In the Backman et al. (2012) zonation scheme zone CNPL8 is defined as running from the FO of Gephyrocapsa >4 µm to the LAD of Gaphyrocpasa >5.5 µm.
Last occurrence (top): in mid part of MIS-38 Isotope stage (50% up, 1.3Ma, in Calabrian stage). Data source: Raffi et al. 2006, Fig. 2 - recorded by them as large Gephyrocapsa spp. HO
First occurrence (base): in mid part of MIS-60 Isotope stage (50% up, 1.7Ma, in Calabrian stage). Data source: Raffi et al. 2006, recorded by them as medium Gephrocapsa spp. LO
Plot of occurrence data:
Backman, J., Raffi, I., Rio, D., Fornaciari, E. & Palike, H. (2012). Biozonation and biochronology of Miocene through Pleistocene calcareous nannofossils from low and middle latitudes. Newsletters on Stratigraphy. 45(3): 221-244. gs Bukry, D. (1973a). Coccolith stratigraphy, eastern equatorial Pacific, Leg 16, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 16: 653-711. gs Matsuoka, H. & Okada, H. (1990). Time-progressive morphometric changes of the genus Gephyrocapsa in the Quaternary sequence of the tropical Indian Ocean, Site 709. Proceedings of the Ocean Drilling Program. Scientific Results. 115: 255-270. gs Perch-Nielsen, K. (1985a). Cenozoic calcareous nannofossils. In, Bolli, H. M. , Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs Pujos-Lamy, A. (1977b). Essai d'etablissement d'une biostratigraphie du nannoplancton calcaire dans le Pleistocene de l'Atlantique Nord-oriental. Boreas. 6: 323-331. gs Raffi, I. et al. (2006). A review of calcareous nannofossil astrobiochronology encompassing the past 25 million years. Quaternary Science Reviews. 25: 3113-3137. gs Rio, D. (1982). The fossil distribution of coccolithophore genus Gephyrocapsa Kamptner and related Plio-Pleistocene chronostratigraphic problems. Initial Reports of the Deep Sea Drilling Project. 68: 325-343. gs Samtleben, C. (1980). Die Evolution der Coccolithophoriden-Gattung Gephyrocapsa nach Befunden im Atlantik. Paläontologische Zeitschrift. 54: 91-127. gs Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 225-265. gsReferences:
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Gephyrocapsa lumina compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-7-2019
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