Facies Analyses, Chronostratigraphy and Paleo- Environmental Reconstructions of Jurassic to Cretaceous Sequences of the Congo Basin - Geology and Resource Potential of the Congo Basin - page 139

South North

N180

a b

c

Fig. 8.7 Inland donga of red sandstones at the Vunza streamwater head (WP97; Fig. 8.3 ). ( a ) Aeolian stratification. ( b ) Meniscate burrow ( arrow )
of type Crane fly larvae (Pemberton et al. 1992 ). ( c ) In-situ calcrete concretions

shallow marine, (2) aeolian, (3) fluvial-deltaic, and (4) lacus-
trine, which serve as a basis for the following regional
correlations and paleo-environmental interpretations.

8.4 Facies Analysis and Depositional Modes

Derived from the Samba and Dekese
Cores

The J-K sequences in the center of the CB are primarily
described from re-logging the Samba and Dekese cores at
the RMCA museum in Belgium (Fig. 8.8a ).
From the two examined core-sections, 19 facies and
subfacies are documented (Table 8.1 ). These include: (a)
conglomerates; (b) sandstones; (c) fine-grained facies and
shales; and (d) paleosols. Further descriptions and photos of
the cores are in Linol ( 2013 ).
The different facies successions are integrated into four
depositional models (Figs. 8.9 , 8.10 , 8.11 , 8.12 and 8.13 ): (1)

8.5 Sequence Stratigraphic Correlations

and Paleo-Environmental Interpretations

The vertical changes of facies and depositional environment
variations observed within the Samba and Dekese cores are
used to define shallowing and deepening upward cycles of
different scale, or depositional sequences (e.g. Galloway and
Hobday 1996 ). Based on this sequence-stratigraphic analysis
(Fig. 8.8b ), correlations are then further extended to the