Geology Reference
In-Depth Information
Pb/
206
Pb dates on presumed
syngenetic galena, yielded 1040 Ma and 1065 Ma (Cahen
1954
;
Holmes and Cahen
1955
). Amygdaloid basaltic pillow lavas at the
Sankuru-Mbuji-Mayi confluence,
207
Fig. 4.1
Simplified geological map of the Sankuru-Mbuji-Mayi-
Lomami-Lovoy Basin in the Kasai-Oriental region (Democratic
Republic of the Congo). Also shown are location of drillcores (S70
Tshinyama, B13 Kanshi, Bena Kalenda, Bena Tshovu, Kafuku 15) and
outcrops (stops 226, 243, 628, 602). In the south, the BI Group overlies
the 1155
and BII Groups, constrained by
40
Ar-
39
Ar date yield 928
20 Ma,
and overlie the Mbuji-Mayi Supergroup.
40
Ar-
39
Ar dating on dolerite
located in the eastern part of the SMLL basin have 888.2
15 Ma Kibara Supergroup (Delhal et al.
1966
). Concordant
U-Pb dates on detrital zircon grains from the BId Subgroup yielded
1174
8.8 Ma
dates. (Delpomdor et al.
2013a
). Although no reliable data on the
deepening direction have been reported, Raucq (
1970
) suggested a
general southward deepening of the basin
22 Ma, which are consistent with the maximum K-Ar age of
1152
15 Ma (Delpomdor et al.
2013a
). The transition between the BI
the Geological Department of the Royal Museum for Central
Africa (RMCA) in Tervuren (Belgium). A detailed
lithological description of these drillcores is provided by
Raucq (
1970
). The total studied drillcores (Fig.
4.2
)is
~525 m. It intersects stratigraphic levels from the BIb to
BIId subgroups. Here, we use the lithological descriptions of
Raucq (
1957
,
1970
) for the siliciclastic series (BI group), but
for the carbonate series we updated the descriptions using a
new nomenclature to reflect the degree of diagenetic alter-
ation. 750 samples of carbonates from split core (10 cm
in diameter) at sampling intervals of
0.3 m were collected
in the BIe subgroup (S70 Tshinyama and Kafuku 15
drillcores), BIIb Subgroup (Bena Kalenda and B13 Kanshi
drillcores), BIIc Subgroup (B13 Kanshi drillcore), and BIId
Subgroup (Bena Tshovu drillcore). In addition, 33 samples
from outcrops intersecting the BIIa (stops 226 and 243) and
Search WWH ::
Custom Search