DYNAMICS and ACTIVE PROCESSES - International Lithosphere ...

Figure 1 – Geological context of the Upper Cretaceous calciturbidites (Moisiu &
Gurabardhi, 2004)
Microfacies 1-Radiolarian mudstone: they correspond to radiolarian mudstone with some
pelagic foraminifera, oxides and collophane fragments.
Microfacies 2-Mudstone to fine wackestone: the grains are around 50 µm with stratiform
grain orientation, in a micritic matrix. The identifiable fauna is pelagic foraminifera. It was
encountered in fine-grained turbidites and in finer intervals of medium- and coarse-grained
intervals (i.e. Te interval).
Microfacies 3-Laminated wackestone: it displays an oblique or stratiform lamination with
a 100-200 µm granulometry range. The fauna is both of shallow water and deeper water with
pelagic foraminifera. It is associated to medium-grained and coarse-grained turbidites (i.e. Tb
to Td intervals).
Microfacies 4-Grain oriented bioclastic/lithoclastic wackestone-floatstone: the sorting is
poor, the granulometry is around 300µm to 2mm and a grain orientation occurs. The
identified fauna is both of shallow water and deep water. Platform extraclasts and some
mudclasts were also observed. This microfacies is associated to Tb to Td intervals of mediumgrained
and coarse-grained turbidites.
Microfacies 5-Bioclastic/lithoclastic wackestone-floatstone: the grains (mean >1mm) are
poorly sorted and consist of shallow and deep water bioclasts, turbiditic microfacies-like
intraclasts and plate-forms extraclasts. This microfacies was encountered in mud-flow levels,
in coarser intervals such as Ta of Bouma (1962) or in topmost of very coarse-grained
calciturbidites.
Microfacies 6-Bioclastic/lithoclastic packstone-rudstone: the sorting is moderate to poor,
the mean granulometry is higher than 300 µm. The components are bioclasts of shallow and
deep water settings and in a lesser degree lithoclasts with mainly extraclasts. This facies is
associated with the coarser intervals (i.e. Ta-Tb) of medium- and coarse-grained turbidites.
Microfacies 7-Extraclastic floatstone-rudstone: the sorting is poor, the granulometry is
millimetric to centimetric. The lithoclasts represented by shallow-water extraclasts are
numerous relatively to bioclasts. The bioclasts are of deep-water and shallow water origin.
This microfacies was observed locally in three coarser levels (Ta or Tb) of coarse-grained
turbidites.
The consituants of calciturbidites are more or less fragmented fauna and lithoclasts.
Shallow-water tests commonly encountered are rudists, large-shelled bivalves and benthic
foraminifera (miliolids, rotaliids, orbitoides and siderolites sp.) with some omphalocyclus
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