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In-Depth Information
337 km
NORTH
Samba (core)
Mbandaka (well log)
Ba
se-lev
el
Rise
Major
sequences
Ba
se-lev
el
Rise
C
SfSm
S
c
S
G
r
P
Fall
0 m
C
Sf
S
m
S
c
S
G
r
P
Fall
0 m
S1
KALAHARI
GROUP
TERRESTRIAL
100 m
M1
100 m
S2
200 m
S
andstone
S3c
FLUVIAL
200 m
M2
d
S
il
t
st
o
ne
non-calca
reous
300 m
300 m
M2c
S
a
n
dstone
p
o
or
l
y sorted
S3b
FLUVIAL
D
ELTA
M2
b
400 m
400 m
SEMI-
PERENIAL
LAKE
S3a
500 m
M2a
500 m
Cla
y
st
o
ne
c
a
lc
a
r
e
ous
S
4d
600 m
600 m
M3c
S4c
C
l
a
ys
t
o
n
es
700 m
700 m
M
3b
S4b
P
E
R
ENIAL
L
AKE
800 m
M3a
Sh
al
e
s
S4a
800 m
M4
Arkose
S5c
900 m
F
L
UVIAL
DELTA
Sea /
Lake
Soil /
Dunes
Delta
River
S5
b
1000 m
S5a
1100 m
TI
D
AL
S6
1200 m
Sea /
Lake
Soil /
Dunes
Delta
River
Fig. 8.14
Regional correlation profile of the J-K Stanleyville, Loia,
Bokungu and Kwango sequences (and the Cenozoic Kalahari Group)
across the central CB (Fig.
8.1
for borehole locations). The Upper
Jurassic Stanleyville Group in the Samba section comprises a main
transgressive sequence of tidal and flood deposits (sub-Unit S5a)
overlain by regressive front bar sandstones (sub-Units S5b and S5c).
The overlying middle Cretaceous Loia and Bokungu Groups in the
Samba (Units S3 and S4), Gilson (Units G2 and G3) and Mbandaka
(Units M2 and M3) sections comprise several regressive sequences of
lacustrine deposits that correlate laterally to (northward) prograding
fluvial delta sandstones with paleosols in the Dekese section (Units D2
and D3)
(LA-MC-ICP-MS; e.g. Cocherie and Robert
2008
) at the
AEON EarthLAB. The method for samples preparation
and the experimental and analytical procedures are
described in detail in Linol (
2013
); see also Chap.
7
, this
Topic.
8.6
U-Pb Detrital Zircons Dates and Source
Provenances Analysis
Detrital zircons collected from the (aeolian) J-K succession
in the CB were U-Pb dated by Laser Ablation Multi-
Collector Inductively Coupled Plasma Mass Spectrometer
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