Total-Hg and Pb-210 measurements in canopy and lake sediments at the pic Matecho, a pristine site in the tropical rainforest of French Guiana (South America)
| Type | Article | ||||||||
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| Date | 2003-05 | ||||||||
| Language | English | ||||||||
| Author(s) | Melieres Ma, Pourchet M, Cossa Daniel, Charles-Dominique P, Gaucher P | ||||||||
| Affiliation(s) | Univ Grenoble 1, CNRS, Lab Glaciol & Geophys Environm, F-38402 St Martin Dheres, France. IFREMER, Dept Polluants Chim, F-44311 Nantes 3, France. MNHN, Lab Ecol Gen, F-91800 Brunoy, France. Mission Creat, F-97326 Cayenne, French Guiana. |
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| Source | Journal De Physique Iv (1155-4339) (EDP Sciences), 2003-05 , Vol. 107 , P. 859-862 | ||||||||
| DOI | 10.1051/jp4:20030433 | ||||||||
| Abstract | We present results obtained from a pristine site of French Guiana (South America), at the Pic Matecho, a region far from gold mining activity. This area contains a small permanent lake, a rare situation in French Guiana. Tree canopy, soils and Lake Matecho sediments were analysed in total Hg and Pb-210. The annual deposit of litterfall is estimated at 40 mug (Hg)/m(2)/y. The top sediment content of 0.2 mug (Hg)/g indicates a large contribution of the atmospheric deposit. In sediment, the decrease of total Hg with depth is neither due to local human influence, nor to increase of atmospheric background during this century. It is attributed to remineralization of organic matter in the upper part of the sediment : the majority of the total Hg deposited at the water/sediment interface is not permanently trapped in the sediment but remobilized in water. Interpretation of the historical sediment profile suggests a constant deposit rate over the last millennium. | ||||||||
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