People at Fort Hoofddijk

Pauline Kruiver
back to People at the Fort
Dr. P.P. Kruiver
PhD 1997-2001
Now at:
CSO Adviesbureau voor
Regulierenring 20
3981 LB Bunnik
Phone: +31 30 659 4321
Fax: +31 30 657 1792



Research of Pauline Kruiver

High-resolution rock magnetic and geochemical analyses of diagenetic effects on the NRM in marine and continental sedimentary environments
back to top of page A long title for a research topic, but what is it all about? The geomagnetic field behaviour can be studied using the Natural Remanent Magnetization (NRM) of rocks and sediments. 
The NRM signal is a composite, however, of the geomagnetic field during deposition or formation of the rock, the grain size and concentration of the magnetic material, and the type of magnetic minerals. Moreover, the magnetic minerals can be altered after deposition through diagenesis. This does not only change the magnetic minerals, but also the magnetic signal they are carrying.
A marine sedimentary core from the Azores (North Atlantic Ocean), spanning the last 270.000 years. This core was used to determine a paleo-intensity record with the pseudo-Thellier method. 
We find that the record is still slightly contaminated by climatically induced changes. A combined rock-magnetic/ geochemical fuzzy c-means cluster analysis shows remarkable agreement between clusters and the climate signal d18O. In this core there was no evidence for diagenesis.

A red bed sequence from Dôme de Barrot (Southern France) of Permian age. The patterns of natural remanent magnetisation (NRM) of this rock resemble those of present day's secular variation. This suggests that during Kiaman Superchron secular variation was not suppressed, and is comparable to present-day SV seen in low latitude lavas. However, to verify secular variation during a Superchron, a precise time control is required. We found that we could confirm the precessional origin of the cyclicity in the Permian redbeds.

Figure 2 from Kruiver et al. (2000)
The La Gloria section (Spain). In this section there are several reversals. The different magnetic minerals recorded the reversals at different times. Timing of the different components, using the clearly astronomically induced sedimentary cycles, may reveal the extent and timing of diagenesis and the NRM acquisition mechanism.
Mark Dekkers (right) helps with drilling the continental sediments of the La Gloria section.

Librilla section

The Librilla section in Southern Spain (left). This is a beautiful continental section with cyclic patterns of red clay, a paleosol, dark grey clay, red or light grey clay and dark grey clay again. 

The largest part of the section has normal polarity. The grey layers are an exception: they have reversed polarity. Diagenesis changed the normal polarity recorded by the sediments during deposition to the reversed polarity after the reversal, which is located near the top of the section.

publications Publications of Pauline Kruiver
  • Vlag, P.A., Kruiver, P.P and Dekkers, M.J. (2004). Evaluating climate change by multivariate statistical techniques on magnetic and chemical properties of marine sediments (Azores region), Palaeogeogr. Palaeoclimatol. Palaeoecol., 212, 23-44. 
  • Grygar T., Dedecek J., Kruiver P.P., Dekkers M.J., Bezdicka P., and Schneeweis, O. (2003). Iron oxide mineralogy in late Miocene red beds from La Gloria, Spain: rock-magnetic, voltammetric and Vis spectroscopy analyses, Catena, 53, 115-132.   [PDF]
  • Kruiver, P.P., Langereis, C.G., Dekkers, M.J. and Krijgsman, W. (2003). Rock magnetic properties of multi-component natural remanent magnetisation in alluvial red beds (NE Spain), Geophys. J. Int., 153, 317-332   [PDF]
  • Heslop, D., Dekkers, M.J., Kruiver, P.P. and Van Oorschot, I.H.M. (2002). Analysis of isothermal remanent magnetisation acquisition curves using the expectation-maximisation algorithm. Geophys. J. Int., 148, 58-64.   [PDF] [SOFTWARE]
  • Kruiver, P.P., Langereis, C.G., Dekkers, M.J., Davies, G.R. and Smeets, R.J  (2002a). The implications of non-suppressed geomagnetic secular variation during the Permo-Carboniferous Superchron, Phys. Earth Planet. Inter., 131, 225-235.   [PDF]
  • Kruiver, P.P., Krijgsman, W., Langereis, C.G. and Dekkers, M.J. (2002b). Cyclostratigraphy and rock-magnetic investigation of the NRM signal in late Miocene palustrine-alluvial deposits of the Librilla section (SE Spain), J. Geophys. Res., 107, B12, 2334, doi:10.1029/2001JB000945   [PDF]


  • Kruiver, P.P. (2001). Unravelling the magnetic record in marine and continental sediments : climatic versus geomagnetic signals (PhD Thesis Utrecht University), Geologica Ultraiectina, 210, 207 pp.   [PDF entire thesis or link to individual chapters]
  • Kruiver, P.P., Dekkers, M.J., and Heslop, D. Quantification of magnetic coercivity components by the analysis of acquisition curves of isothermal remanent magnetisation, Earth Planet. Sci. Lett., 189, 269-276.    [PDF]
  • Kruiver, P.P. and Passier, H.F. (2001). Coercivity analysis of magnetic phases in sapropel S1 related to variations in redox conditions, including an investigation of the S-ratio. Geochem. Geophys. Geosyst., 14 December 2001, Paper number 2001GC000181  [PDF]   [link to G-cubed]
  • Kruiver, P.P., Dekkers, M.J. and Langereis, C.G. (2000). Secular variation in Permian red beds from Dôme de Barrot, SE France, Earth Planet. Sci. Lett., 179, 205-217. [PDF]
  • Kruiver, P.P., Kok, Y.S., Dekkers, M.J., Langereis, C.G. and Laj, C. (1999). A pseudo-Thellier relative palaeointensity record, and rock magnetic and geochemical parameters in relation to climate during the last 276 kyr in the Azores region. Geophys. J. Int., 136 (3): 757-770.    [PDF]   [DATA]
  • Kruiver, P.P., Kok, Y.S., Dekkers, M.J. and Langereis, C.G. (1998). Rock-magnetic and geochemical parameters in relation to climate, using fuzzy c-means cluster and spectral analyses, In: A. Buccianti, G. Nardi and R. Potenza (Eds.), Proceedings of IAMG'98, Isola d’Ischia, Naples (Italy), 1998, Part 1, 427-432.