People at Fort Hoofddijk

Anja Dijkhuizen
K.A. Dijkhuizen
Paleomagnetic Laboratory
Fort Hoofddijk
Department of Earth Sciences, 
Utrecht University 
Budapestlaan 17
3584 CD Utrecht 
The Netherlands 

Phone +31 30 253 5248
E-mail K.A.Dijkhuizen@students.uu.nl

Research
Publications
 




Research of Anja Dijkhuizen

Barberton Scientific Drilling Program: 
The roots of life and tectonic Earth 
Five decades of scientific research in the 3500-3100 million year old Barberton Greenstone Belt has established the mountain ranges around the small and picturesque town of Barberton as a world heritage site and a playground for international scientists interested in early Earth processes. 

The Barberton Greenstone Belt represents relatively intact and undisturbed remnants of preserved ancient seafloor and continental crust that have largely escaped tectonic reworking since the time they formed. These rocks allow to test the physico-chemical and biological processes that were operating during the formation of the Earth’s early crust. 

There are major outstanding questions about Early Earth that address our understanding of geological, geophysical, chemical and biological processes.

These include research related to: 

  • Vertical (plume-driven) versus horizontal (plate-tectonic-driven) type crustal mechanisms for the early Archean
  • Chemical and tectonic make up of the oldest greenstone belts 
  • Earth’s early magnetic field and magnetosphere
Addressing these questions using analytical  techniques, for example, stable isotope geochemistry and paleomagnetic studies on surface outcrops has, however, some major pitfalls:
  • Sparse and discontinuous outcrops
  • Surface samples are open weathering and/or other chemical alteration processes
  • lightning strikes and magnetic overprints hinder obtaining records of unequivocal primary remnance 
Clearly, the best way to directly 
access information related to early Earth processes would be by diamond core drilling to retrieve fresh, chemically representative samples from depth.
Fig. 1 Barberton Greenstone Belt

Fig. 2 Location of BSDP drill cores

Illustrations are from the AEON - BSDP drilling report, see also the BSDP drilling webpage. The BSDP project is also reported in EOS and in Scientific Drilling by Grosch et al. (2009a,b). 

Barberton Scientific Drilling Program (BSDP)
Drilling was aimed on the mostly tholeiitic 3.47-3.44 Ga upper Onverwacht Group of the Swaziland Supergroup in the southwesternmost BGB (Fig. 1), along the world renowned Komati River (Fig. 2). The rocks exposed here include the Mendon, Kromberg and Hooggenoeg Formations of the Onverwacht Group. Three diamond core boreholes were drilled, namely KD1 (Kromdraai 1) and KD 2a and 2b (simplified lithological log). 
Location and block diagrams of the three drill sites in the Barberton Greestone Belt (see also the report on Drilling in 2008 from the Norwegian Centre for Geobiology, in Bergen, Norway)

A   core   orientation   tool,   EASYMARKTM,   was   used   to   fix   the   orientation   of   the   drilled core in space, particularly for paleomagnetic studies of basalts.

In this project, we focus on the paleomagnetism of the BSDP drill core. Anja Dijkhuizen has taken small samples (8 mm cores) from this core for this purpose, using a specially made diamond drill bit. She will focus on early Earth geomagnetic field behaviour and on paleolatitudes of the formations, and depending on results throughout the sampled intreval, possibly also for deriving (plate or plume) tectonic processes. She is supervised by Cor Langereis

publications Publications of Anja Dijkhuizen