Namibia/SIMBA

Seismic investigations in the Messum and Brandberg area

Continental breakup at the Namibia passive margin was accompanied by emplacement of a large number of subvolcanic ring-type intrusive complexes in northern Namibia (the Damaraland complexes). The seismic experiment SIMBA is focussed on the detailed crustal structure around one of the largest intrusive complexes, Messum. It furthermore aims to complement the northernmost profile of the MAMBA'95 experiment. The two projects are part of the interdisciplinary & GFZ Namibia project.

The near-vertical seismic measurements consisted of 125 shots (16 kg charge size) across a 75 km long profile. 180 seismic channels were deployed with spacing of 100 m. The resulting CDP fold is about 17. Beside CDP processing and imaging, the direct waves are used for tomographic velocity determination of the uppermost crust.

Time Frame

April - May 1998

Funding

GFZ - Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

Principal Investigators

A. Schulze
T. Ryberg
S. Sobolev
R. Trumbull
T. Vietor
M. Weber
K. Bauer

Cooperations

Geological Survey of Namibia

Methods & Equipment

Imaging of reflectivity
Tomography for P and S wave velocity structure
Integration of potential field data

Publications/Results

Bauer, K., R.B. Trumbull, and T. Vietor (2003): Geophysical images and a crustal model of intrusive structures beneath the Messum ring complex, Namibia, Earth Planet. Sci. Lett., 216, 65-80.
Bauer, K., A. Schulze, T. Ryberg, S.V. Sobolev, and M.H. Weber (2003): Classification of lithology from seismic tomography: A case study from the Messum igneous complex, Namibia, J. Geophys. Res., 108(B3), 2152,doi:10.1029/2001JB001073.
Vietor, T., R.B. Trumbull, N.R., Nowaczyk, D.G. Hutchins, and R. Emmermann, Insights on the deep roots of Mesozoic ring complexes in Namibia from aeromagnetics and gravity modelling of the Messum and Brandberg complexes (2001): Zeitschrift der Deutschen Geologischen Gesellschaft, 152, 157-174
Bauer, K., Charakterisierung eines vulkanisch geprägten passiven Kontinentalrandes mit seismischen Verfahren am Beispiel Namibias (2001): Dissertation, Universität Potsdam, 125 pp.

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