GEOSCAN, résultats de la recherche


TitreGeochemical mapping employing active and overbank stream-sediment, lake sediment and lake water in two areas of Newfoundland
AuteurMcConnell, J W; Finch, C; Hall, G E M; Davenport, P H
SourceGeochemical mapping; par Davenport, P H (éd.); Journal of Geochemical Exploration vol. 49, no. 1,2, 1993 p. 123-143,
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 51693
ÉditeurElsevier BV
RéunionGoldschmidt Conference; Reston, Virgina; US; 199205??; mai 1992
Documentpublication en série
Mediapapier; en ligne; numérique
SNRC12H/09; 12H/10; 12H/15; 12H/16; 12I/01; 2E/13; 1M/13; 1M/14; 1M/15; 2E/12
Lat/Long OENS -57.0000 -54.5000 50.2500 47.7500
Sujetsdépôts alluviaux d'inondation; levés géochimiques; géochimie des sédiments de cours d'eau; géochimie de l'eau; géochimie des sediments lacustres; géochimie des eaux lacustres; géochimie de l'argent; géochimie de l'arsenic; géochimie de l'or; géochimie du baryum; géochimie du brome; géochimie du cerium; géochimie du cobalt; géochimie du chrome; géochimie du césium; géochimie du cuivre; géochimie du fer; géochimie du gallium; géochimie de l'hafnium; géochimie du lanthane; géochimie du lithium; géochimie du manganèse; géochimie du molybdène; géochimie du niobium; géochimie du sodium; géochimie du nickel; géochimie du terbium; géochimie du tantale; géochimie du strontium; géochimie du samarium; géochimie du scandium; géochimie de l'antimoine; géochimie du rubidium; géochimie du plomb; géochimie du thorium; géochimie de l'uranium; géochimie du vanadium; géochimie du tungsten; géochimie de l'yttrium; géochimie de l'ytterbium; géochimie du zinc; géochimie du zirconium; analyses; analyses des éléments en trace; analyses géochimiques; géochimie
Illustrationsanalyses; sketch maps
Résumé(disponible en anglais seulement)
Geochemical data from samples of active and overbank stream sediment in one area and from lake sediment and lake water in another are compared and evaluated. Samples of both types of stream sediment were collected from drainage basins 2-10 km2 in area in a glaciated landscape and the < 63 µm fractions were analyzed for 38 elements. In general, trace element distribution patterns are similar in the two media and reflect the chemistry of the underlying bedrock. Absolute concentrations are higher for most elements in the overbank sediment. For elements having concentrations near the analytical detection limit, such as Au, Mo and Pb, the overbank sediment provides more reliable data in those parts of the area with low background levels. In this area, suitable overbank material is more widespread and available for sampling than is active sediment. In some drainages, stream-sediment data are clearly contaminated by past mining activity but overbank data appear unaffected. Lake water was collected from another area where a lake sediment survey had been conducted eleven years earlier. The < 180 µm fraction of sediment was analyzed for 29 elements and the water for about 50 elements. Due to the contrasting nature of these two sample media, element distribution patterns are less similar than in the case of the two types of stream sediment. Nonetheless, elements which are hydromorphically dispersed and which are partitioned consistently between water and sediment (such as F, U, As, and rare earths) do demonstrate a strong spatial correlation. As analytical detection limits for water continue to improve, the versatility of this medium in geochemical mapping will increasingly complement more conventional sampling media as well as providing an alternate medium in areas where sediment is unavailable.