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| Titel |
Hydrogeology and hydrogeochemistry of an alkaline volcanic area: the NE Mt. Meru slope (East African Rift – Northern Tanzania) |
| VerfasserIn |
G. Ghiglieri, D. Pittalis, G. Cerri, G. Oggiano |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 2 ; Nr. 16, no. 2 (2012-02-17), S.529-541 |
| Datensatznummer |
250013181
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| Publikation (Nr.) |
 copernicus.org/hess-16-529-2012.pdf |
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| Zusammenfassung |
| The objective of this study is to analyze the geochemical conditions
associated with the presence of fluoride (F−) in the groundwater of an area
of Northern Tanzania. The studied aquifers are composed of volcanic rocks
such as phonolitic and nephelinitic lavas, basalts, lahars of various ages
and mantling ash. Sedimentary rocks consisting of fine-grained alluvial and
lacustrine deposits occur as well. Samples collected from springs, borehole
and surface water, during two monitoring surveys, were analyzed for the
various physico-chemical and isotopic parameters. The geochemical
composition of water is typically sodium bicarbonate. High values of F−
(up to 68 mg l−1) were recorded. The highest values of fluoride agreed with the highest values of
pH, sodium and bicarbonate. Dissolution of major ions, exchange processes
and precipitation of Ca2+ from super-saturated solutions joined with
the local permeability and hydraulic gradients, control the fluoride
mobilization and the contamination of the area. |
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