Resumo As técnicas de análise multivariada utilizadas nesta pesquisa tiveram por objetivo identificar e avaliar as variáveis químicas responsáveis pela contaminação da área urbana de Boquira, Bahia, devido ao abandono da bacia de rejeitos da mineração de Pb-Zn, com a finalidade de auxiliar nas medidas de gerenciamento ambiental na área. Foram realizadas a análise fatorial em componentes principais e de agrupamento. A análise fatorial permitiu agrupar as variáveis em dois fatores principais para as amostras de sedimentos de rua, somando 72% da variância total acumulada e em três fatores para as amostras de poeira de casas, que explicaram 77% do total da variância. As variáveis apresentam forte correlação com a composição da bacia de rejeitos. A análise de agrupamento classificou as amostras de acordo com a concentração dos metais na área, onde pode-se concluir a influência da bacia de rejeitos e do backgound natural das rochas da região na distribuição da contaminação.

Abstract This study employed multivariate analysis techniques to identify and evaluate the chemical variables responsible for the contamination of the urban area of Boquira, Bahia, due to the abandonment of the tailings basin of Pb-Zn mining, in order to assist in the environmental management of the area. Factor analysis was performed on main and grouping components. The factor analysis allowed grouping the variables into two main factors for street sediment samples, adding up to 72% of the total accumulated variance, and three factors for house dust samples, which explained 77% of the total variance. The variables have a strong correlation with the composition of the tailings basin. Cluster analysis classified the samples according to the concentration of metals in the area, where the influence of the tailings basin and the natural background of the region's rocks in the contamination distribution can be identified.

ABSTRACT: The objective of the present study was to interpret the direction of gravitational sedimentary flows in the turbidite deposits of the Maracangalha Formation (Recôncavo Basin), indicating their source areas. Thus, the indicative deformational structures existing in the formation were analyzed. The structures observed ranged from brittle to highly ductile and viscous states, with a diversity of deformational styles. A total of 284 planar and linear measurements was collected in three distinct subareas, separated according to their degree of deformation. The structures found were separated into four groups according to their formation process: (i) pre-deformation structures; (ii) plastic deformation structures; (iii) intrusion structures (fluidization), related to either early or syn-sedimentation events; and finally (iv) brittle deformation structures, with late sedimentation. Some structures were observed to be good indicators of apparent mass movement direction, which yielded predominantly SSW directions, suggesting a partially confined flow, parallel to the main axes of Recôncavo Basin, towards its depocenter.