140
Baumann et al.
mental tracers as well as to add to the paleoclimatic
relevance of some ofthe coccolithophore taxa. In
addition, more information from sediment trap studies is needed for a better understanding of the transformation of a living coccolithophore community
into a coccolith assemblage of deep-sea sediments.
2) Analysis of coccoliths from sediment cores
of these regions provides useful information on
the location of different water masses in the
past and consequently on the paleoecology and
paleoceanography of these areas. The highest
numbers of coccoliths in GeoB 1028 and 1117 are
observed during relatively cold periods and are not
only due to temperature changes but seem to indicate relatively nutrient-rich waters. In addition,
contrasting cyclic variations in coccolith accumulation rate and relative abundance of the deepdwelling species F. profunda are correlated to a
varying nutrient supply to the upper euphotic zone.
Furthermore, increased occurrences of G.
oceanica seem to be more indicative of relatively
increased productivity than of higher water temperatures.
There are still deficits in understanding the influence effective on the coccolithophores as part
of the total phytoplankton primary production, in
order to use the record of coccolith production as
a primary productivity proxy.
3) Compositional variations in the coccolith assemblage determined in sediment cores already
indicate relative temperature changes. Past SSTs
can be determined absolutely by alkenones studies (Uk'37-index), which already have become
standard technique for temperature estimates in
paleoceanographic studies. The Uk'37-based SST
record in GeoB 1028 indicates a cyclic and largescale fluctuation of about SoC between the maximum interglacial temperatures and the minimum
glacial temperatures.
However, determination of the chemotaxonomic significance of variability in these and
other potential biomarkers and palaeothermometer
calibrations needs to be performed on the species
producing alkenones. Also, the relationship between alkenone-derived SST data, alkenone concentrations, and coccolithophore assemblages still
is an open question.
Acknowledgments
We are grateful to H. Thierstein (ZUrich) and J.
Giraudeau (Bordeaux) who made useful suggestions on the manuscript. We would like to express
thanks to K. Zonefeld (Bremen), H. Andruleit
(Hannover), and G. Fischer (Bremen) for their
comments on improving an earlier version ofthe
manuscript. Furthermore, we would like to thank
master and crew of the RV 'Meteor' and numerous unnamed colleagues for their help during ship
expeditions. C. Wienberg and S. Hiineke is thanked
for technical assistance. This research was funded
by the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 261 at Bremen University, Contribution No. 220). Data are available under
www.pangaea.delProj ects/SFB261.
References
Ahagon N, Tanaka Y, Ujiie H (1993) Florisphaera profunda, a possible nannoplankton indicator of
late Quaternary changes in sea-water turbidity at
the northwestern margin of the Pacific. Mar
Micropaleontol22: 255-273
AndruleitH (1996) A filtration technique for quantitative studies of coccoliths. Micropaleontology 42:
403406
Andruleit H (1997) Coccolithophore fluxes in the Norwegian-Greenland Sea: seasonality and assemblage
alterations. Mar Micropaleontol31 : 45-64
Backman J, Shackleton NJ (1983) Quantitative
Biochronology of Pliocene and Early Pleistocene
calcareous nannofossils from the Atlantic, Indian
and Pacific Ocean. Mar Micropaleontol8: 141-170
Bassinot FC, Beaufort I, Vincent E, Labeyrie L (1997)
Changes in the Dynamics of western Equatorial
Atlantic surface currents and biogenic productivity
at the "Mid-Pleistocene Revolution" (930 ka). In
Shackleton NJ, Curry WB, Richter C, Bralower TJ
(eds) Proc ODP Sci Results 154: 269-284
Baumann K-H (1990) Verlinderlichkeit der Coccolithophoriden-Fauna des Europliischen Nordmeeres im Jungquartlir. Ber SFB 313 Univ Kie122, pp
1-146
Beaufort L, Lancelot Y, Camberlin P, Cayre 0, Vincent E,
BassinotF, Labeyrie L (1997) Insolation cycles as a
major control of Equatorial Indian Ocean Prymary
Production. Science 278: 1451-1454
Bickert T (1992) Rekonstruktion der splitquatliren
Bodenwasserzikulation im ostlichen Siidatlantik
Baumann et al.
mental tracers as well as to add to the paleoclimatic
relevance of some ofthe coccolithophore taxa. In
addition, more information from sediment trap studies is needed for a better understanding of the transformation of a living coccolithophore community
into a coccolith assemblage of deep-sea sediments.
2) Analysis of coccoliths from sediment cores
of these regions provides useful information on
the location of different water masses in the
past and consequently on the paleoecology and
paleoceanography of these areas. The highest
numbers of coccoliths in GeoB 1028 and 1117 are
observed during relatively cold periods and are not
only due to temperature changes but seem to indicate relatively nutrient-rich waters. In addition,
contrasting cyclic variations in coccolith accumulation rate and relative abundance of the deepdwelling species F. profunda are correlated to a
varying nutrient supply to the upper euphotic zone.
Furthermore, increased occurrences of G.
oceanica seem to be more indicative of relatively
increased productivity than of higher water temperatures.
There are still deficits in understanding the influence effective on the coccolithophores as part
of the total phytoplankton primary production, in
order to use the record of coccolith production as
a primary productivity proxy.
3) Compositional variations in the coccolith assemblage determined in sediment cores already
indicate relative temperature changes. Past SSTs
can be determined absolutely by alkenones studies (Uk'37-index), which already have become
standard technique for temperature estimates in
paleoceanographic studies. The Uk'37-based SST
record in GeoB 1028 indicates a cyclic and largescale fluctuation of about SoC between the maximum interglacial temperatures and the minimum
glacial temperatures.
However, determination of the chemotaxonomic significance of variability in these and
other potential biomarkers and palaeothermometer
calibrations needs to be performed on the species
producing alkenones. Also, the relationship between alkenone-derived SST data, alkenone concentrations, and coccolithophore assemblages still
is an open question.
Acknowledgments
We are grateful to H. Thierstein (ZUrich) and J.
Giraudeau (Bordeaux) who made useful suggestions on the manuscript. We would like to express
thanks to K. Zonefeld (Bremen), H. Andruleit
(Hannover), and G. Fischer (Bremen) for their
comments on improving an earlier version ofthe
manuscript. Furthermore, we would like to thank
master and crew of the RV 'Meteor' and numerous unnamed colleagues for their help during ship
expeditions. C. Wienberg and S. Hiineke is thanked
for technical assistance. This research was funded
by the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 261 at Bremen University, Contribution No. 220). Data are available under
www.pangaea.delProj ects/SFB261.
References
Ahagon N, Tanaka Y, Ujiie H (1993) Florisphaera profunda, a possible nannoplankton indicator of
late Quaternary changes in sea-water turbidity at
the northwestern margin of the Pacific. Mar
Micropaleontol22: 255-273
AndruleitH (1996) A filtration technique for quantitative studies of coccoliths. Micropaleontology 42:
403406
Andruleit H (1997) Coccolithophore fluxes in the Norwegian-Greenland Sea: seasonality and assemblage
alterations. Mar Micropaleontol31 : 45-64
Backman J, Shackleton NJ (1983) Quantitative
Biochronology of Pliocene and Early Pleistocene
calcareous nannofossils from the Atlantic, Indian
and Pacific Ocean. Mar Micropaleontol8: 141-170
Bassinot FC, Beaufort I, Vincent E, Labeyrie L (1997)
Changes in the Dynamics of western Equatorial
Atlantic surface currents and biogenic productivity
at the "Mid-Pleistocene Revolution" (930 ka). In
Shackleton NJ, Curry WB, Richter C, Bralower TJ
(eds) Proc ODP Sci Results 154: 269-284
Baumann K-H (1990) Verlinderlichkeit der Coccolithophoriden-Fauna des Europliischen Nordmeeres im Jungquartlir. Ber SFB 313 Univ Kie122, pp
1-146
Beaufort L, Lancelot Y, Camberlin P, Cayre 0, Vincent E,
BassinotF, Labeyrie L (1997) Insolation cycles as a
major control of Equatorial Indian Ocean Prymary
Production. Science 278: 1451-1454
Bickert T (1992) Rekonstruktion der splitquatliren
Bodenwasserzikulation im ostlichen Siidatlantik