Sea-level fluctuations of different order - Analysis and quantification of shallow marine sedimentation pattern and their controlling factors within the Cretaceous Tethys
Martina Bachmann and Jochen Kuss
DFG project Ku 642/13
The study was focused on the analysis of controlling
factors on platform deposition with respect to sea-level change and platform
geometry. During Mid-Cretaceous times, the northern Sinai and northern
Israel depositional environments both were without important tectonic
movements and were characterized by similar paleogeographic positions
but different platform geometries (carbonate ramp versus carbonate platform).
This allows interpretation of sedimentation patterns with respect to the
controlling factors: sea-level change, biogenic control, sedimentary input
and platform geometry.
Biostratigraphic analyses are based on orbitolinids, ammonites (O. F.
Geyer), ostracods (M. A. Bassiouni), rudists (T. Steuber) and calcareous
algae. Detailed field work (sectioning and sampling, determination of
the sedimentary structures) and microfacies analysis result in the reconstruction
of the deposional environments reflecting the different paleogeographic
situations. Sequence stratigraphic interpretation allows the interpretation
of changing environmental factors in connection with sea-level changes.
Biostratigraphic analysis and graphic correlation result in the timing
of the sequences and allow the correlation with local, regional and global
signals.
Results of these studies were published: Geyer et al. (1996), Bachmann
et al. (1996), Bachmann & Kuss (1998), Steuber & Bachmann (2002).
For further methods like clay-mineralogy, sediment-petrography, and paleoecological
proxies see the following paper: Kunow et al. (1998), Kim et al. (1999).