Auxillary Material for
Time-Transgressive North Atlantic Productivity Changes upon Northern
Hemisphere Glaciation
K.T. Lawrence1*, D.M. Sigman2, T.D. Herbert3, C.A. Riihimaki4, C.T. Bolton5, A.
Martinez-Garcia6,7, A. Rosell-Mele7,8, and G.H. Haug6
1
Department of Geology and Environmental Geosciences, Lafayette College, Easton, PA
18042, USA
2
3
Department of Geosciences, Princeton University, Princeton, New Jersey, 08544, USA
Department of Geological Sciences, Brown University, Providence, Rhode Island 02912,
USA
4
Council on Science and Technology, Princeton University, , New Jersey, 08544, USA
5
Departamento de Geologia, Universidad de Oviedo, Arias de Velasco s/n, 33005
Oviedo, Asturias, Spain
6
Department of Earth Sciences, Geological Institute, ETH Zürich, CH-8902 Zürich,
Switzerland
7
Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona,
Cerdanyola del Vallès, 08193 Catalonia, Spain
8
Institucio Catalana de Recerca I Estudis Avancats, Barcelona, 08010 Catalonia, Spain
Paleoceanography 2013
Introduction
This section contains supplementary figures that primarily display datasets that
have been previously published (cited appropriately below). The novel data shown
in figures fs01.eps, fs02.eps, fs04.eps are the productivity data from ODP sites 907
(alkenone MAR and opal MAR) and 662 (alkenone MAR). Information about the
methodologies employed to generate these datasets are included in the methods
section of the manuscript or in the appropriate figure caption below. Collectively,
these figures provide information which support the methodological approaches
employed as well as the interpretations made in this paper.
1. fs01.eps Surface conditions at North Atlantic Site 907. A) Biogenic opal %
(orange) versus alkenone concentration (ug/g) (black) (this study). B) C37 alkenone
MAR (ug/cm2/kyr) (black line) (this study) and IRD (purple line) (note the inverted
axis) [Jansen et al., 2000]. Both biogenic opal and alkenone concentration data
record the same overall pattern, indicating an early (>3 Ma) decline of productivity
at Site 907. As observed at other high latitude localities in the Northern Hemisphere
(e.g. site 982, Figure 3), the decline in productivity at site 907 is associated with a
dramatic increase in IRD at this locality. Low resolution biogenic opal
measurements for site 907 were performed at Brown University using
spectrophotometer and the methodology outlined in [Mortlock and Froelich, 1989].
2. fs02.eps Productivity Records from Equatorial Atlantic Site 662. A) Biogenic opal
% [Ruddiman and Janecek, 1989] (light blue) versus C37 alkenone concentration
(nmol/g) (this study) (yellow) for the interval from 3 to 1.6 Ma. B) Opal MAR
(g/cm2/kyr) [Ruddiman and Janecek, 1989] (light blue) versus C37 alkenone (MAR)
(ug/cm2/kyr) this study (yellow). Despite being derived from different groups of
organisms and being susceptible to very different diagenetic processes both
concentration data and MAR data indicate a tight coupling between variations in
biogenic opal and C37 alkenones. These results suggest that both of these indices are
proxies for past productivity and that they are recording changes in export
productivity at this locality. Interproxy comparisons among different productivity
indices from other tropical as well as high latitude localities suggest this conclusion
can be broadly generalized [Bolton et al., 2011; Bolton et al., 2010].
3. fs03.eps Surface conditions at North Atlantic Site 607. A) Uk’37 sea surface
temperature (ºC) estimates [Lawrence et al., 2010] (red), and alkenone mass
accumulation rates (MAR) (ug/cm2/kyr) (green) (note the inverted axis); B) 41 kyr
band phase relationships between SST and productivity (-c37total) at 607. Gray
shading identifies the interval of high productivity. SST and productivity proxies are
coherent and in phase for most of the high productivity interval in the 41k band,
demonstrating that SST and productivity show tight coupling on orbital timescales
with increase in productivity associated with decreases in SST.
4. fs04.eps Surface conditions at North Atlantic Site 662. A) Uk’37 sea surface
temperature (ºC) estimates [Herbert et al., 2010] (red), and B) alkenone mass
accumulation rates (MAR) (ug/cm2/kyr) (green) (this study)(note the inverted
axis). Gray shading identifies the interval of high productivity.
References
Bolton, C. T., K. T. Lawrence, S. J. Gibbs, P. A. Wilson, and T. D. Herbert (2011), Biotic
and geochemical evidence for a global latitudinal shift in ocean biogeochemistry and
export productivity during the late Pliocene, Earth and Planetary Science Letters,
308, 200-210.
Bolton, C. T., K. T. Lawrence, S. J. Gibbs, P. A. Wilson, L. C. Cleaveland, and T. D.
Herbert (2010), Glacial-interglacial productivity changes recorded by alkenones and
microfossils in the late Pliocene eastern equatorial Pacific and Atlantic upwelling
zones, Earth and Planetary Science Letters, 295, 401-411.
Herbert, T. D., L. C. Peterson, K. T. Lawrence, and Z. Liu (2010), Tropical Ocean
Temperatures Over the Past 3.5 Myr, Science, 328, 1530-1534.
Jansen, E., T. Fronval, F. Rack, and J. E. T. Channell (2000), Pliocene-Pleistocene ice
rafting history and cyclicity in the Nordic Seas during the last 3.5 Myr,
Paleoceanography, 15(6), 709-721.
Lawrence, K. T., S. Sosdian, H. E. White, and Y. Rosenthal (2010), North Atlantic
Climate Evolution Through the Plio-Pleistocene Climate Transitions, Earth and
Planetary Science Letters, 300, 329-342.
Mortlock, R. A., and P. N. Froelich (1989), A Simple Method for the Rapid
Determination of Biogenic Opal in Pelagic Marine Sediments, Deep-Sea Research,
36(9), 1415-1426.
Ruddiman, W. F., and T. R. Janecek (1989), Pliocene-Pleistocene Biogenic and
Terrigenous Fluxes at Equatorial Atlantic Sites 662, 663 and 664, in Proceeding of
the Ocean Drilling Program, Scientific Results, edited by W. F. Ruddiman, M.
Sarnthein, J. G. Baldauf and R. Heath, pp. 211-240, Ocean Drilling Program, College
Station, TX.