Geoquímica de sedimentos de corrente no Anticlinal de Valongo, norte de Portugal: arsénio como um indicador para delinear novos alvos de exploração

ABSTRACT: The Valongo anticline is known for the occurrence of several Sb-Au and As-Au mineral deposits, many of which have been exploited since Roman times. The Sb-Au and As-Au deposits occur in brecciated quartz veins, predominantly trending NE-SW, NNW-SSE, and ENE-WSW, cutting Cambrian to Carboniferous formations. An 801-stream sediment campaign was conducted in this area. Factorial kriging was applied as an interpolation method as it enables the estimation and mapping of the individual spatial components of the variogram. Arsenic (As) was used as a proxy to outline new exploration targets. The results allow the identification of NW-SE and NE-SW alignments as preferential areas for elevated As contents. Future studies will incorporate structural information and the distribution of old mine dumps to achieve higher accuracy in target areas for mining prospection.