Sea-Surface Temperature Estimations Using a Modern Analog
Technique with Foraminiferal Assemblages from Western Atlantic
Quaternary Sediments
W Hale l ' and U Pflaumann 2
1 Universitat Bremen, Fachbereich Geowissenschaften, Postfach 33 0440,
D-28334 Bremen, Germany
2Geologisch-Palaontologisches 1nstitut, Universitat Kiel, Olshausenstrafie 40,
D-241 18 Kiel, Germany
*corresponding author (e-mail):whale@uni-bremen.de
Abstract: Paleotemperature estimates calculated by the SIMMAX Modern Analog Technique are
presented for two gravity cores from the Rio Grande Rise, one from the Brazil Slope, and one from the
Ceara Rise. The estimates are based on comparisons between modern and fossil planktonic
foraminiferal assemblages and were carried out on samples from Quaternary sediments. Estimated
warm-season temperatures from the Rio Grande Rise (at approx. 30° S) range from around 19°C to
24°C, with some coincidence of warm peaks with interglacial stages. The temperature estimates (also
warm-season) from the more tropical Brazil Slope (at approx. 8° S) and Ceara Rise (at approx. 4°N)
cores are more stable, remaining between 26°C and 28°C throughout most of their lengths. This fairly
stable situation in the tropical western Atlantic is interrupted in oxygen isotope stage 6 by a significant
drop of2-3°C in both of these cores. Temperature estimates from the uppermost samples in all cores
compare very well to the modem-day measured values. Affinities of some foraminiferal species for
warmer or cooler surface temperatures are identified within the temperature range of the examined
samples based on their abundance values. Especially notable among the warmer species are,
Globorotalia menardii, Globigerinita glutinata,Globigerinoides ruber, and Globigerinoides
sacculifer. Species indicative of cooler surface temperatures include Globorotalia injlata, Globigerina
bulloides, Neogloboquadrina pachyderma, and Globigerina falconensis. A cluster analysis was
carried out to assist in understanding the degree of variation which occurs in the foraminiferal
assemblages, and how temperature differences influence the faunal compositions of the samples. It
is demonstrated that fairly similar samples may have unexpectedly different estimated temperatures
due to small differences in key species and, conversely, quite different assemblages can result in
similar or identical temperature estimates which confirms that other parameters than just temperature
affect faunal content.
Introduction
The primary objective ofthis chapter is to present
and discuss the results of our temperature calculations and to examine some ofthe assemblage distributions that coincide with variations in temperature. In addition, we assess the applicability ofthe
SIMMAX method (Ptlaumann et al. 1996) and how
it can be employed in conjunction with other techniques to improve our general knowledge of past
ocean conditions.
Identifying a reliable and accurate method of
reconstructing sea-surface temperatures for the
past several hundred thousand years has become a
primary goal of recent paleoceanographic studies.
Planktonic foraminifera have been extensively
employed for paleoenvironmental interpretations
because of their widespread geographical and geological occurrence, their abundance, and their sensitivity to environmental conditions, particularly temFrom FISCHER G, WEFER G (eds), 1999. Use of Proxies in Paleoceanography: Examplesfrom the South Atlantic. Springer-Verlag
Berlin Heidelberg, pp 69-90
Technique with Foraminiferal Assemblages from Western Atlantic
Quaternary Sediments
W Hale l ' and U Pflaumann 2
1 Universitat Bremen, Fachbereich Geowissenschaften, Postfach 33 0440,
D-28334 Bremen, Germany
2Geologisch-Palaontologisches 1nstitut, Universitat Kiel, Olshausenstrafie 40,
D-241 18 Kiel, Germany
*corresponding author (e-mail):whale@uni-bremen.de
Abstract: Paleotemperature estimates calculated by the SIMMAX Modern Analog Technique are
presented for two gravity cores from the Rio Grande Rise, one from the Brazil Slope, and one from the
Ceara Rise. The estimates are based on comparisons between modern and fossil planktonic
foraminiferal assemblages and were carried out on samples from Quaternary sediments. Estimated
warm-season temperatures from the Rio Grande Rise (at approx. 30° S) range from around 19°C to
24°C, with some coincidence of warm peaks with interglacial stages. The temperature estimates (also
warm-season) from the more tropical Brazil Slope (at approx. 8° S) and Ceara Rise (at approx. 4°N)
cores are more stable, remaining between 26°C and 28°C throughout most of their lengths. This fairly
stable situation in the tropical western Atlantic is interrupted in oxygen isotope stage 6 by a significant
drop of2-3°C in both of these cores. Temperature estimates from the uppermost samples in all cores
compare very well to the modem-day measured values. Affinities of some foraminiferal species for
warmer or cooler surface temperatures are identified within the temperature range of the examined
samples based on their abundance values. Especially notable among the warmer species are,
Globorotalia menardii, Globigerinita glutinata,Globigerinoides ruber, and Globigerinoides
sacculifer. Species indicative of cooler surface temperatures include Globorotalia injlata, Globigerina
bulloides, Neogloboquadrina pachyderma, and Globigerina falconensis. A cluster analysis was
carried out to assist in understanding the degree of variation which occurs in the foraminiferal
assemblages, and how temperature differences influence the faunal compositions of the samples. It
is demonstrated that fairly similar samples may have unexpectedly different estimated temperatures
due to small differences in key species and, conversely, quite different assemblages can result in
similar or identical temperature estimates which confirms that other parameters than just temperature
affect faunal content.
Introduction
The primary objective ofthis chapter is to present
and discuss the results of our temperature calculations and to examine some ofthe assemblage distributions that coincide with variations in temperature. In addition, we assess the applicability ofthe
SIMMAX method (Ptlaumann et al. 1996) and how
it can be employed in conjunction with other techniques to improve our general knowledge of past
ocean conditions.
Identifying a reliable and accurate method of
reconstructing sea-surface temperatures for the
past several hundred thousand years has become a
primary goal of recent paleoceanographic studies.
Planktonic foraminifera have been extensively
employed for paleoenvironmental interpretations
because of their widespread geographical and geological occurrence, their abundance, and their sensitivity to environmental conditions, particularly temFrom FISCHER G, WEFER G (eds), 1999. Use of Proxies in Paleoceanography: Examplesfrom the South Atlantic. Springer-Verlag
Berlin Heidelberg, pp 69-90