Abstract
Surface soils (0–15 cm) were sampled at 10–20 km intervals along two transects in Venezuela. One (1162 km, 70 samples) ran west to east parallel with the Caribbean coastline, the other (920 km, 92 samples) ran south to north from the frontier with Brazil to the Caribbean shore. Sampling took place in both a wet and a dry season. Trace metals were extracted from dried, sieved (<2 mm) soil with boiling aqua regia followed by analysis by ICP or flame AAS. Metal values did not differ significantly between the two seasons and dates were averaged. Geometric mean values for the west–east transect were: Cr = 41.5, Cu 17.9, Cs 3.6, Li = 13.9, Mn = 294, Ni = 21.3, Pb = 17.4, Sr = 39.4, V = 60.4 and Zn = 83.7 μg g−1, respectively. Similarly, for the south–north transect Cr = 21.3, Cu = 4.3, Cs = 1.1, Li = 2.0, Mn = 55.7, Ni = 4.4, Pb = 6.1, Sr = 13.3, V = 28.2 and Zn = 16.7 μg g−1, respectively. A classification of samples by lithology showed surface soil composition to be related to rock composition. Metal values were low in the soils in the south of the country, in the Guyana highlands (Gran Sabana). Low Zn contents were prevalent. Lead contents were affected by roadside fallout from vehicles using leaded petrol except that high Pb contents of soils in the Gran Sabana were of more complex origin.
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Baghdady, N.H. and Sippola, J.: 1983, Total heavy metal recovery by aqua regiain soils of different origin, Annales Agriculturae Fenniae 22, 175-178.
Berrow, M.L. and Stein, W.M.: 1983, Extraction of metals from soils and sewage sludges by refluxing with aqua regia, Analyst 108, 277-285.
Blancaneaux, P. and Pouyllau, M.: 1977, Les relations geomorpho-pedologiques de la retombee nordoccidentale du massif guyanais (Venezuela)-part 1:les concepts et definitions, Cahiers ORSTOM, ser Pedologie 15, 437-448.
Briceno, H.O. and Schubert, C.: 1990, Geomorphology of the Gran Sabana, Guyana Shield, southeastern Venezuela, Geomorphology 3, 125-141.
Bucher, W.H.: 1952, Geologic structure and oroganic history of Venezuala, New York, Geological Society of America, 113 p.
Cochrane, T.T., Sanchez, L.G., de Azevedo, L.G., Porras, J.A. and Garver, C.L.: 1985, Land in tropical America: Cali, Columbia, Centro Internacional de Agricultura Tropical 1, 144 p.
Davies, B.E. and Wixson, B.G.: 1985, Trace elements in surface soils from the mineralised area of Madison county, Missouri, USA, Journal of Soil Science 36, 551-570.
Drosdoff, M.: 1972, Soil micronutrients, in: Drosdoff, M. (ed), Soils of the Humid Tropics. Washington DC, USA, National Academy of Sciences, p. 151-162.
Dubroeucq, D. and Volkoff, B.: 1988, Evolution des couvertures pedologiques sableuses a podzols geants d'Amazonie (bassin du Haut rio Negro), Cahiers ORSTOM, ser Pedologie 24, 191-214.
Garcia-Miragaya J.: 1984, Levels,chemical fractionation, and solubility of lead in roadside soils of Caracas, Venezuela, Soil Science 138, 147-152.
Gibbs, AK. and Barron, C.N.: 1983, The Guiana shield reviewed, Episodes 2, 7-14.
Holt, J.A. and Coventry, R.J.: 1990, Nutrient cycling in Australian savannas, Journal of Biogeography 17, 427-432.
Kanwar, J.S. and Youngdahl, L.J.: 1985, Micronutrient needs of tropical food crops, in: P.L.G. Vlek (ed) Micronutrients in Tropical Food Production. Developments in Plant and Soil Sciences edition, Dordrecht, Martinus Nijhoff/Dr W Junk, vol. 14, pp. 43-67.
Lopez, V.M., Hedberg, H.D. and Kehrer, L.: 1956, Venezuela, in: Jenks, W.F. (ed), Handbook of South American Geology. New York, Geological Society of America, Memoir 65, p. 329-349.
Matteucci, S.D., Colma, A. and Pla, L.: 1985, Multiple-purposes land mapping and resources inventory, Environmental Management 9(3), 231-242.
McGrath, S.P. and Cunliffe, C.H.: 1985, A simplified method for the extraction of the metals Fe, Zn, Cu,. Ni, Cd, Pb, Cr, Co and Mn from soils and sewage sludges, Journal of the Science of Food and Agriculture 36, 794-798.
Medina, E. and Silva, J.F.: 1990, Savannas of northern South America: a steady state regulated by water-fire interactions on a background of low nutrient availability, Journal of Biogeography 17, 403-413.
Mogollon, J.L., Kretien, H. and Bifano, C.: 1987, Contaminacion en sedimentos de la cuenca del Rio Tuy y controles geoquimicos que actuan en el sistema, Acta Cientifica Venezolana 38, 47-58.
Morellato, L.P.: 1992, Nutrient cycling in two south-east Brazilian forests. I Litterfall and litter standing crop, Journal of Tropical Ecology 8, 205-215.
Nriagu, J.O.: 1990, The rise and fall of leaded gasoline, The Science of The Total Environment 92, 13-28.
Paredes, JR. and Buol, SW.: 1981, Soils in an aridic, ustic, udic, climosequence in the Maracaibo Lake Basin, Venezuela, Soil Science Society of America Journal 45, 385-391.
UNEP: 1991, United Nations Environment Programme Environmental Data Report [3rd edn.]: Oxford, England, Denis Blackwell, 4048 p.
Ure, A.M. and Berrow, M.L.: 1982, The elemental constituents of soils, in: Bowen, H.J.M., (ed) Environmental Chemistry, London, Royal Society of Chemistry. 2, p. 94-204.
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Davies, B.E., Bifano, C., Phillips, K.M. et al. Aqua regia extractable trace elements in surface soils of venezuela. Environmental Geochemistry and Health 21, 227–256 (1999). https://doi.org/10.1023/A:1006670415312
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DOI: https://doi.org/10.1023/A:1006670415312