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 151

Table 8.2 Summary of U-Pb detrital zircon dates from sample WP19 (the Lower Kwango Group)
Age-population U-Pb dates ( 206 Pb/ 207 Pb) Notes

1. Mesoarchean One (oldest) zircon dates at 3133 29 Ma

2. Neoarchean 5 zircons date between 2596 27 Ma and Indicate some contributions from Neoarchean aged-terrains.

These dates are similar to dated basement rocks in southern
DRC and northern Angola (Delhal 1991 ; Jelsma et al. 2011),
western Tanzania and Uganda (Link et al. 2010 ), and Gabon
(Caen-Vachette et al. 1988 )

2657 27 Ma

3. Paleoproterozoic 10 zircons date between 1.7 Ga and 2.2 Ga,

with 6 comprised between 1979

Overlap the conventional Eburnian period (e.g. Cahen et al.
1984 ). Such dates are common within the Ruwenzori and
Ubendian Belts in Uganda and western Tanzania (Lenoir et al.
1995 ; Nagudi et al. 2003 ), and within the basements of the West
Congo Belt in western DRC and the Lufilian Arc in Zambia
(Tack et al. 2001 ; Rainaud et al. 2005 ), as well as from their
overlying upper Neoproterozoic to lower Paleozoic sequences
(Master et al. 2005 ; Frimmel et al. 2006 )

29 Ma and

2114 29 Ma

4. Early Neoproterozoic to
late Mesoproterozoic
( Second most common
age-population )

20 zircons date between 850 Ma and
1200 Ma, with 17 bracketed between
922

This major peak at 1000 Ma correspond to the general Kibaran
age in Africa (e.g. Cahen et al. 1984 ), although its type area in
eastern DRC, Rwanda and Burundi has been shown to be older,
ca. 1375 Ma (Tack et al. 2010 )

34 Ma and 1044 33 Ma

5. Late Neoproterozoic
( Most common age-population )

24 zircons date between 544 37 Ma and Indicate large contributions from Pan African aged-terrains,

such as the West Congo, Oubanguides, Mozambique and
Lufilian Belts

854 38 Ma

8Ma( 206 Pb/ 238 U

6. Early Paleozoic One zircon dates at 426 No Silurian sources have been identified across central Africa.

Such dates are common within the Andes and proto-Andes in
Patagonia (Pankhurst et al. 1998 ; Vaughan and Pankhurst, 2008 )

date)

7. Early Jurassic Two (youngest) zircons date at 204 4Ma

and 192 4Ma

Overlap with the CAMP and Karoo LIPs, ca. 200 Ma and
182 Ma respectively (Marzoli et al. 1999 ; Svensen et al. 2012 ;
Blackburn et al. 2013 ), and Carboniferous to Jurassic felsic
volcanism and magmatism of the Choiyoi and Chon Aike
igneous provinces in southern South America (Kay et al. 1989 )

Table 8.3 Summary of U-Pb detrital zircon dates from samples D470 and D600 (the Dekese Formation)
Age-population

U-Pb dates ( 206 Pb/ 207 Pb)

Notes

1. Mesoarchean One (oldest) zircon dates at

2942 17 Ma

2. Early Paleoproterozoic to
Neoarchean

15 zircons date between 2.3 Ga and
2.7 Ga, with 11 concentrated between
2553

These dates can correspond to the Kasai, NE Angola, Ntem,
Mboumou and Tanzanian Cratons

11 Ma and 2665 16 Ma

3. Paleoproterozoic 15 zircons date between 1.8 Ga and

2.3 Ga, with 4 restricted between
1964

Indicate some contributions from Eburnian aged-terrains

13 Ma and 1974 17 Ma, and

2 at 2075 12 Ma and 2080 17 Ma

4. Mesoproterozoic 6 zircons date between 1.2 Ga and 1.5 Ga,

with only 2 concordant at 1272 23 Ma
and 1548 13 Ma

This suggests that the Kibaran Belt, dated at ca. 1375 Ma (Tack
et al. 2010 ), was not major source

35 zircons date between 844 19 Ma and
1187 48 Ma

5. Early Neoproterozoic to
late Mesoproterozoic
( Second most common
age-population )

Indicate significant contributions from late Mesoproterozoic
aged-terrains (distinctively younger than the Kibaran type-area)

6. Early Paleozoic to late
Neoproterozoic
( Most common age-
population )

64 zircons date between 513 21 Ma and Coincide with Pan African tectono-metamorphic events in

Africa (e.g. Cahen et al. 1984 ). These dates are abundant within
the West Congo, Oubanguides, Mozambique and Lufilian Belts

837 21 Ma

7. Permian-Triassic Two (youngest) zircons date at

240

Coincide with Permian-Triassic kimberlites discovered in
northern Angola (Jelsma et al. 2011 ), or more likely to felsic
volcanism and magmatism of the Choiyoi Province in western
Argentina and eastern Chile (e.g. Munizaga et al. 2008 )

6 Ma and 286 7Ma

( 206 Pb/ 238 U dates)