Geochemistry of clay dunes and associated pan in the Senegal delta, Mauritania
| Autor: | Raoul Caruba, Abdallahi Ould Mohamedou, Vincent Valles, Alain Aventurier, Laurent Barbiero |
|---|---|
| Přispěvatelé: | Université de Nouakchott, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA), Institut National de la Recherche Agronomique (INRA), Institut de recherche pour le développement (IRD [Sénégal]), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université de Nouakchott Al-Aasriya (UNA), Université Nice Sophia Antipolis (1965 - 2019) (UNS) |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Delta
SALINITE 010504 meteorology & atmospheric sciences Geochemistry Plant Science SOL DEGRADE 01 natural sciences CALCITE chemistry.chemical_compound Érosion éolienne lunettes [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Sol de dune Calcite Sol à pan argileux ALCALINISATION Sol de delta Géochimie 04 agricultural and veterinary sciences Composition chimique Aeolian deflation ARGILE Halite Aeolian processes Geology P33 - Chimie et physique du sol Soil salinity Gypsum GYPSE engineering.material complex mixtures EROSION EOLIENNE SOLUTION DU SOL BARRAGE EAU SOUTERRAINE [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment 0105 earth and related environmental sciences Earth-Surface Processes DUNE DELTA Senegal delta Sol alcalin saline soils chemistry Soil water 040103 agronomy & agriculture engineering 0401 agriculture forestry and fisheries Groundwater |
| Zdroj: | Arid Soil Research and Rehabilitation Arid Soil Research and Rehabilitation, Informa UK (Taylor & Francis), 1999, 13 (3), pp.265-280. ⟨10.1080/089030699263302⟩ Arid Soil Research and Rehabilitation, 1999, 13 (3), pp.265-280. ⟨10.1080/089030699263302⟩ |
| ISSN: | 0890-3069 1521-0405 |
| DOI: | 10.1080/089030699263302⟩ |
| Popis: | Since the construction of the anti-salting Diama dam, a resumption of aeolian deflation has been observed in the Senegal delta and particularly in Diawling National Park. It results in the formation of many clay dunes with high salt concentrations. The soft powdery structure observed on the soil surface, affected by aeolian deflation is due to rapid salt crystallization. In order to identify the mineralogy of the salt involved in this environment, the chemistry of soil and groundwater was studied along a transect from a pan to the associated clay dune. Equilibria computation and field and scanning electron microscope (SEM) observations indicated that the changes observed in the chemical facies of the solution were due to the following precipitation sequence : calcite to gypsum to halite. A progressive but significant fixing of Na+ onto the clay particles was observed. The calcite deposition in the soil was limited by exhibition of the potential acidity arising from the former mangrove site soils. It resulted in high equilibrating pCO2. This study intended to test a new extension to the Debye-Hückel law for concentrated chlorurated sodic waters. The relationship between chloride amounts and the residual alkalinity concept confirmed that calcite and gypsum formation and the exchanges between Na and Ca are the main phenomena responsible for the changes observed in the soil solution (r2 = 0.99). (Résumé d'auteur) |
| Databáze: | OpenAIRE |
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