Análise estatística aplicada a prospecção geoquímica de ouro na área designada 5246AD

Abstract

Soils have been one of the most used sampling methods in geochemical cartography, serving as areference for geological cartography, mineral prospecting and metallogenic studies given their foundation, which is based on the fact that soils reflect the composition of the parent rock. The geochemical data to be processed and interpreted resulted from fieldwork carried out by the National Institute of Mines (INAMI) in the Designated Area 5246 AD for Gold exploration in the District of Changara, Tete Province between the 7th of July and the 1 st of August 2018. During this activity, 135 samples of stream sediments were collected in the Designated Area 5246 AD,previously defined for studies, an area of 6,461.01 hectares. The samples were sent for chemicalanalysis of a total of 15 chemical elements (K, Ca, Ti, V, Sc, Cr, Ni,Sb, Cu, Zn, Co, Au, Fe, Pb and Mn) where they were extracted using the Bulk technique. cyanide Leach (BCL). To understand the variables studied, univariate statistics were applied for post-selection of backgroundlevels and geochemical anomalies, culminating in the creation of maps of level distributions. Bivariate statistics made it possible to group the variables according to their geochemical affinity, allowing thedistinction of three groups with a weak, medium and strong positive correlation. And the factor analysis applied in the multivariate study allowed the distinction of five factors - association of Ti-V-Mn-Fe-Zn forming factor 1, association of K-Au-Pb which represents factor 2, the association Cr-Ni -Cu forming factor 3, factor 4 formed by Ca-Sc-Co and factor 5 formed only by Sb. Geostatistical analysis was used to indicate the zones of occurrence of geochemical associations by factorial analysis and to determine the spatial distribution of element contents. ASTER image processing allowed identification of the main structures – lineaments of the study area.