Multiphase Phanerozoic Subsidence and Uplift History Recorded in the Congo Basin: A Complex Successor Basin - Geology and Resource Potential of the Congo Basin - page 214

A B

1

2

3

Fig. 11.5 Total subsidence curves for the Samba, Dekese, Gilson and
Mbandaka well/core data in the central CB (Fig. 11.1 for location). The
curves show two main episodes of subsidence ( A and B ), including
three phases of rapid subsidence (1-3, arrowed ) separated by episodes

of slower subsidence or uplift ( highlighted columns ). Dotted lines
correspond to calculated subsidence without paleo-topography input
(paleo-elevation ¼ 0)

Ma. It contains two distinct phases of rapid subsidence [ca.
10-50 m/Ma]: from 150-160 Ma to 140 Ma (Phase 2), and
from 110 Ma to 50 Ma (Phase 3). These two phases coincide
with the main period of break-up of Gondwana, and West
Gondwana, that respectively resulted in the opening of the
Indian and South Atlantic Oceans (e.g. Jokat et al. 2003 ).
These two phases of subsidence are remarkably similar in all
the four sections (Fig. 11.5 ), and all terminated with a major
uplift at about 30-50 Ma (Fig. 11.6 ), recorded by the
condensed Kalahari Group (see Fig. 11.3 ).

2-4 m/Ma] and continuous subsidence since the late Pre-
cambrian (Neoproterozoic) proposed in previous studies
(e.g. Crosby et al. 2010 ; Kadima et al. 2011 ). The most
important differences between these subsidence models
arise from the stratigraphic databases used. Below, we
describe some of the recent improvements to the strati-
graphic framework and regional correlations of the CB
(Linol 2013 ), as a basis from which to evaluate further its
subsidence and tectonic evolution during the Phanerozoic
(Fig. 11.7 ).
Following the Pan African orogens (ca. 530-650 Ma;
de Wit et al. 2008 ), widespread upper Neoproterozoic to
lower Paleozoic continental red-bed sediments (the Inkisi,
Aruwimi and Biano Groups) were deposited across pene-
plained Precambrian basement of central Africa. These red-
beds are about 1,000-1,500 m thick flanking the peripheral
Pan African fold-and-thrust belts of the CB (Lepersonne
1974 ; Alvarez et al. 1995 ; Master et al. 2005 ; Tait et al.
2011 ; Chap. 6 , this Topic). Yet their stratigraphic equivalents

11.3 Tectono-Stratigraphic Synthesis

In summary, the four curves of total subsidence in the CB
show two main episodes of basin subsidence [ca. 5-20 m/
Ma]: during (a) the Carboniferous to Early Jurassic, and
during (b) the Late Jurassic to early Paleogene (Fig. 11.5 ).
These results differ significantly from the very slow [ca.