Geological Influence on Stream Sediments Geochemistry from Precambrian Terrains of Uruguay
José Maria Filippini Alba
*
Embrapa Clima Temperado, Laboratório de Planejamento Ambiental, Box post 403, Pelotas, RS, CEP 96010-971, Brazil.
*Author to whom correspondence should be addressed.
Abstract
The National Mining and Geology Directorate of Uruguay (DINAMIGE) recovered, in 2020, geochemical data of Uruguayan Precambrian terrains collected in the 80’s, involving 31,874 soil and stream sediment samples. These samples were analyzed for 22 elements (Ag, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Nb, Ni, P, Pb, Sb, Sn, V, W, Y and Zn) by direct current plasma spectrometry. Multivariate statistical methods and geographic information system (GIS) procedures applied on a set of 20786 geochemical samples, 84% of total geochemical regional sampling from Uruguay, aiming characterization of geochemical signatures. The work focused on analyzing the influence of geology on the geochemical signature, considering 34 geological formations. The Chuy Formation appeared as the most impoverished and five geological formations stood out from the rest.
Keywords: Anomaly, background, environment, geochemical exploration, outliers, trace elements