Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 24 November 1995:
Vol. 270. no. 5240, pp. 1347 - 1351
DOI: 10.1126/science.270.5240.1347
Prev | Table of Contents | Next

Reports

North Atlantic Deepwater Temperature Change During Late Pliocene and Late Quaternary Climatic Cycles

Gary S. Dwyer (1),  Thomas M. Cronin,  Paul A. Baker,  Maureen E. Raymo,  Jeffrey S. Buzas,  Thierry Corrège (2)

Variations in the ratio of magnesium to calcium (Mg/Ca) in fossil ostracodes from Deep Sea Drilling Project Site 607 in the deep North Atlantic show that the change in bottom water temperature during late Pliocene 41,000-year obliquity cycles averaged 1.5°C between 3.2 and 2.8 million years ago (Ma) and increased to 2.3°C between 2.8 and 2.3 Ma, coincidentally with the intensification of Northern Hemisphere glaciation. During the last two 100,000-year glacial-to-interglacial climatic cycles of the Quaternary, bottom water temperatures changed by 4.5°C. These results show that glacial deepwater cooling has intensified since 3.2 Ma, most likely as the result of progressively diminished deepwater production in the North Atlantic and of the greater influence of Antarctic bottom water in the North Atlantic during glacial periods. The ostracode Mg/Ca data also allow the direct determination of the temperature component of the benthic foraminiferal oxygen isotope record from Site 607, as well as derivation of a hypothetical sea-level curve for the late Pliocene and late Quaternary. The effects of dissolution on the Mg/Ca ratios of ostracode shells appear to have been minimal.


G. S. Dwyer and P. A. Baker, Department of Geology, Duke University, Durham, NC 27708, USA.
T. M. Cronin, U.S. Geological Survey, Branch of Paleontology and Stratigraphy, Mail Stop 970 National Center, Reston, VA 22092, USA.
M. E. Raymo, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
J. S. Buzas, Department of Mathematics and Statistics, University of Vermont, Burlington, VT 05051, USA.
T. Corrège, Départment de Géologie et Océanographie, Université de Bordeaux I, Avenue des Facultés, Bordeaux, France.
(1) To whom correspondence should be addressed.
(2) Present address: Laboratoire des Formations Superficielles, ORSTOM, 32 Avenue Henri Varagnat, 93143 Bondy Cedex, France.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Deep-Sea Temperature and Ice Volume Changes Across the Pliocene-Pleistocene Climate Transitions.
S. Sosdian and Y. Rosenthal (2009)
Science 325, 306-310
   Abstract »    Full Text »    PDF »
Surface temperatures of the Mid-Pliocene North Atlantic Ocean: implications for future climate.
H. J Dowsett, M. A Chandler, and M. M Robinson (2009)
Phil Trans R Soc A 367, 69-84
   Abstract »    Full Text »    PDF »
Mid-Pliocene sea level and continental ice volume based on coupled benthic Mg/Ca palaeotemperatures and oxygen isotopes.
G. S Dwyer and M. A Chandler (2009)
Phil Trans R Soc A 367, 157-168
   Abstract »    Full Text »    PDF »
Age constraints on the origin and growth history of a deep-water coral mound in the northeast Atlantic drilled during Integrated Ocean Drilling Program Expedition 307.
A. Kano, T. G. Ferdelman, T. Williams, J.-P. Henriet, T. Ishikawa, N. Kawagoe, C. Takashima, Y. Kakizaki, K. Abe, S. Sakai, et al. (2007)
Geology 35, 1051-1054
   Abstract »    Full Text »    PDF »
Climate change, body size evolution, and Cope's Rule in deep-sea ostracodes.
G. Hunt and K. Roy (2006)
PNAS 103, 1347-1352
   Abstract »    Full Text »    PDF »
Elemental and Oxygen Isotope Composition of Early Jurassic Belemnites: Salinity vs. Temperature Signals.
(2004)
Journal of Sedimentary Research 74, 342-354
Regional warming: Pliocene (3 Ma) paleoclimate of Europe and the Mediterranean.
A.M. Haywood, B.W. Sellwood, and P.J. Valdes (2000)
Geology 28, 1063-1066
   Abstract »    Full Text »    PDF »
The Role of Mg2+ as an Impurity in Calcite Growth.
K. J. Davis, P. M. Dove, and J. J. De Yoreo (2000)
Science 290, 1134-1137
   Abstract »    Full Text »
Cenozoic Deep-Sea Temperatures and Global Ice Volumes from Mg/Ca in Benthic Foraminiferal Calcite.
C. H. Lear, H. Elderfield, and P. A. Wilson (2000)
Science 287, 269-272
   Abstract »    Full Text »
Deep-sea ostracode shell chemistry (Mg:Ca ratios) and Late Quaternary Arctic Ocean history.
T. M. Cronin, G. S. Dwyer, P. A. Baker, J. Rodriguez-Lazaro, and W. M. Briggs Jr (1996)
Geological Society, London, Special Publications 111, 117-134
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)