The Magnetic View on the Marine Paleoenvironment
597
terize and distinguish different marine sedimentary
environments. They are all entirely based on the
sediment matrix magnetic properties and more
specifically on mineralogy, concentration, grain-size
and domain state of the magnetic mineral assemblages. Though not yet exploited in their full range
of capacities, the wide variety of distinct rock
magnetic measurements and parameters enables
to discriminate primary input mechanisms ofterrigenous material by fluvial or eolian transport as well
as various source regions and to recognize biogenic
or lithogenic magnetic components of marine origin.
As demonstrated for the recent equatorial South
Atlantic, these Environmental Magnetism methods, combined with appropriate statistical data
evaluation techniques, efficiently identify particular sedimentary regimes and outline their regional
extent. With a sufficiently comprehensive and precisely dated sample collection available, analogous
analyses would be possible for any ocean and time
slice. Rock magnetic core logs determined as highresolution time series for a late Quaternary sediment sequence recovered in the central equatorial
South Atlantic give an elementary example ofthis
strategy. They yield a detailed reconstruction of
sedimentary patterns which reflect pronounced
variations of paleoclimatic and paleoceanographic
conditions primarily documenting a systematic
cyclicity due to orbital forcing. To trace the intense
effects of diagenetic processes on the magnetic
mineral assemblage in a reducing environment,
supplementary transmission electron micrographs
proved to be especially useful. It should be mentioned that most magnctic measurements are nondestructive and, compared to other methods,
accomplished in a relatively short period of time
thereby allowing quite elaborate investigations.
Depcnding on the individual situation, additional
rock magnetic techniques, which have not been
introduced here, e.g., thermomagnetic, anisotropy
or M6J3bauer analyses, may be of critical importance. Finally, rock magnetic and paleomagnetic
data sets have a great potential in establishing highresolution chronostratigraphies for marine sediment
sequences (see Bleil and von Dobeneck; von
Dobeneck and Schmieder this volume).
Acknowledgments
We thank crews and scientific parties of numerous METEOR cruises to the SouthAtiantic for their
cooperation. Contributions of H. Petermann, who
was involved in parts of this work, and constructive
reviews by J.A. Dearing and E. Petrovsky are
gratefully acknowledged. This study was funded
by the Deutsche F orschungsgemeinschaft (Sonderforschungsbereich261, contribution no. 185).
Data are available under www.pangaea.de/
Projects/SFB261.
References
Bacher J (1994) Clusteranalyse: Anwendungsorientierte
Einfiihmng. Oldenbourg Verlag, Miinchen, pp 1-424
Bailey ME, Dunlop DJ (1983) Alternating field characteristics of pseudo-single-domain (2 -14 J.IIIl) and
multi-domain magnetite. Earth Planet Sci Lett 63:
333-352
Banerjee SK (1981) Experimental methods of rock
magnetism and paleomagnetism. Adv Geophys 23:
25-99
Barron EJ, Whitman JM (1981) Oceanic sediments in
space and time. In: Emiliani C (ed) The Sea. Wiley
and Sons, New York, pp 689-73 I
Berner RA (1981) A new geochemical c1assificication of
sedimentary environments. J Sed Petrol 51:359-365
Bezdek JC (1981) Pattern Recognition with Fuzzy Objective Function Algorithms. Plenum Press, New
York, pp 1-256
Bezdek JC, Dunn JC (1975) Optimal fuzzy partitions: a
heuristic for estimating the parameters in a mixture
ofnorrnaldistributions. IEEE TransComp 24:835-838
Bloemendal J, King JW, Hall FR, Doh S-J (1992) Rock
magnetism of late Neogene and Pleistocene deepsea sediments: relationship to sediment source,
diagenetic processes, and sediment lithology. J
GeophysRes 97:4361-4375
Blocmendal J, Lamb B, King J (1988) Paleoenvironmental
implications ofrock magnetic properties oflate quaternary sediment cores from the eastern equatorial
Atlantic. Paleoceanography 3 :61-87
Borradaile GJ, Stupavsky M (1995)Anisotropy of magnetic susceptibility: measurement schemes. Geophys
Res Lett 22:1957-1960
Butler RF, Banerjee SK (1975) Theoretical single-domain
grain size range in magnetite and titanomagnetitc. J
Geophys Res 80:4049-4058
Canfield DE, Berner RA (1987) Dissolution and
597
terize and distinguish different marine sedimentary
environments. They are all entirely based on the
sediment matrix magnetic properties and more
specifically on mineralogy, concentration, grain-size
and domain state of the magnetic mineral assemblages. Though not yet exploited in their full range
of capacities, the wide variety of distinct rock
magnetic measurements and parameters enables
to discriminate primary input mechanisms ofterrigenous material by fluvial or eolian transport as well
as various source regions and to recognize biogenic
or lithogenic magnetic components of marine origin.
As demonstrated for the recent equatorial South
Atlantic, these Environmental Magnetism methods, combined with appropriate statistical data
evaluation techniques, efficiently identify particular sedimentary regimes and outline their regional
extent. With a sufficiently comprehensive and precisely dated sample collection available, analogous
analyses would be possible for any ocean and time
slice. Rock magnetic core logs determined as highresolution time series for a late Quaternary sediment sequence recovered in the central equatorial
South Atlantic give an elementary example ofthis
strategy. They yield a detailed reconstruction of
sedimentary patterns which reflect pronounced
variations of paleoclimatic and paleoceanographic
conditions primarily documenting a systematic
cyclicity due to orbital forcing. To trace the intense
effects of diagenetic processes on the magnetic
mineral assemblage in a reducing environment,
supplementary transmission electron micrographs
proved to be especially useful. It should be mentioned that most magnctic measurements are nondestructive and, compared to other methods,
accomplished in a relatively short period of time
thereby allowing quite elaborate investigations.
Depcnding on the individual situation, additional
rock magnetic techniques, which have not been
introduced here, e.g., thermomagnetic, anisotropy
or M6J3bauer analyses, may be of critical importance. Finally, rock magnetic and paleomagnetic
data sets have a great potential in establishing highresolution chronostratigraphies for marine sediment
sequences (see Bleil and von Dobeneck; von
Dobeneck and Schmieder this volume).
Acknowledgments
We thank crews and scientific parties of numerous METEOR cruises to the SouthAtiantic for their
cooperation. Contributions of H. Petermann, who
was involved in parts of this work, and constructive
reviews by J.A. Dearing and E. Petrovsky are
gratefully acknowledged. This study was funded
by the Deutsche F orschungsgemeinschaft (Sonderforschungsbereich261, contribution no. 185).
Data are available under www.pangaea.de/
Projects/SFB261.
References
Bacher J (1994) Clusteranalyse: Anwendungsorientierte
Einfiihmng. Oldenbourg Verlag, Miinchen, pp 1-424
Bailey ME, Dunlop DJ (1983) Alternating field characteristics of pseudo-single-domain (2 -14 J.IIIl) and
multi-domain magnetite. Earth Planet Sci Lett 63:
333-352
Banerjee SK (1981) Experimental methods of rock
magnetism and paleomagnetism. Adv Geophys 23:
25-99
Barron EJ, Whitman JM (1981) Oceanic sediments in
space and time. In: Emiliani C (ed) The Sea. Wiley
and Sons, New York, pp 689-73 I
Berner RA (1981) A new geochemical c1assificication of
sedimentary environments. J Sed Petrol 51:359-365
Bezdek JC (1981) Pattern Recognition with Fuzzy Objective Function Algorithms. Plenum Press, New
York, pp 1-256
Bezdek JC, Dunn JC (1975) Optimal fuzzy partitions: a
heuristic for estimating the parameters in a mixture
ofnorrnaldistributions. IEEE TransComp 24:835-838
Bloemendal J, King JW, Hall FR, Doh S-J (1992) Rock
magnetism of late Neogene and Pleistocene deepsea sediments: relationship to sediment source,
diagenetic processes, and sediment lithology. J
GeophysRes 97:4361-4375
Blocmendal J, Lamb B, King J (1988) Paleoenvironmental
implications ofrock magnetic properties oflate quaternary sediment cores from the eastern equatorial
Atlantic. Paleoceanography 3 :61-87
Borradaile GJ, Stupavsky M (1995)Anisotropy of magnetic susceptibility: measurement schemes. Geophys
Res Lett 22:1957-1960
Butler RF, Banerjee SK (1975) Theoretical single-domain
grain size range in magnetite and titanomagnetitc. J
Geophys Res 80:4049-4058
Canfield DE, Berner RA (1987) Dissolution and