Congo River (Brazzaville)
Pool Malebo, République du Congo
Rivers and surface water
- Type
- River or surface water
Dissolved silicon heavier than igneous rocks (-0.3 ± 0.3 ‰), a sign of fractionation during weathering and clay formation; the rivers studied by De La Rocha et al. (2000) give +0.8 ± 0.3 ‰ (n = 8). Coordinates of Brazzaville, indicative.
δ30Si in ‰ (per mil) Values of the same system
Standard : NBS 28
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.4 ‰ | 1 | Brazzaville, date not stated. | De La Rocha et al. (2000), A first look at the distribution of the stable isotopes of sil… | |
| 0.8 ‰ | 1 | Sample labelled 'Zaire', exact location not given: 0.4 ‰ off Brazzaville on the same river. | De La Rocha et al. (2000), A first look at the distribution of the stable isotopes of sil… | |
| 1.01 ± 0.12 ‰ | 0.78 / 1.21 ‰ | 13 | filtered river water (dissolved silicon) Mean and standard deviation recalculated from the 13 samples of the main Ubangi-Congo branch, from Bangui (km 0) to below Brazzaville (km 1105), November 1989. Bangui +1.21 ‰; δ30Si drops to +0.88 ‰ at km 335 and reaches its minimum, +0.78 ‰, at km 850, below the Black River confluences, then rises to +1.02 ‰ at km 1105 (discharge 43,100 m³/s). Dissolved silicon 3.8 to 6.6 mg/L. Main branch and large tributaries: +0.98 ± 0.13 ‰ (abstract). Heavy silicon attributed to kaolinite formation in soils. Appendix 3: mean dissolved silicon 5.8 ± 0.9 mg/L; adding the estimated particulate silicon (clays, quartz, diatoms, 4.46 ± 1.12 mg/L), the river's total silicon is -0.09 ± 0.25 ‰, the expected crustal signature (0.00 ± 0.20 ‰ with a stored phytolith pool). No direct particle measurement (1989 filters too lightly loaded). | Cardinal et al. (2010), Contrasting silicon isotope signatures in rivers from the Congo B… |
Deposits of the same type
- Kasai République démocratique du Congo
- Sangha République du Congo
- Black Rivers of the Congo central basin (Likouala, Motaba, Alima) République du Congo
- Lobaye République centrafricaine
- Nile Égypte
- El Sancho reservoir Spain
- Meca River, point B Spain
- Meca River, point A3 Spain
Cite this page
IsoFind Atlas (2026). Congo River (Brazzaville), isotope signatures. https://www.isofind.tech/isotopes/en/sites/congo-brazzaville/ (accessed 2026-10-13).
@misc{isofind2026congoriverbrazzavilleisotopes,
title = {Congo River (Brazzaville), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/sites/congo-brazzaville/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13