Depositional setting, petrology and chemistry of Permian coals from the Paraná Basin: 2. South Santa Catarina Coalfield, Brazil W. Kalkreuth a, ⁎, M. Holz b , A. Mexias a , M. Balbinot a , J. Levandowski a , J. Willett c , R. Finkelman c , H. Burger d a Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil b Inst. de Geociências, UFBA, Salvador, Bahia, Brazil c U.S. Geological Survey, Mail Stop 956 Reston, VA 20192, USA d Freie Universität Berlin, Geoinformatik, Malteserstr 74-100, 12249 Berlin, Germany abstract article info Article history: Received 22 February 2010 Received in revised form 16 August 2010 Accepted 19 August 2010 Available online 16 September 2010 Keywords: South Santa Catarina Coalfield Paraná Basin Brazil Sequence stratigraphy Coal petrology and chemistry Statistical evaluation In Brazil economically important coal deposits occur in the southern part of the Paraná Basin, where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina. The current paper presents results on sequence stratigraphic interpretation of the coal-bearing strata, and petrological and geochemical coal seam characterization from the South Santa Catarina Coalfield, Paraná Basin. In terms of sequence stratigraphic interpretation the precursor mires of the Santa Catarina coal seams formed in an estuarine-barrier shoreface depositional environment, with major peat accumulation in a high stand systems tract (Pre-Bonito and Bonito seams), a lowstand systems tract (Ponta Alta seam, seam A, seam B) and a transgressive systems tract (Irapuá, Barro Branco and Treviso seams). Seam thicknesses range from 1.70 to 2.39 m, but high proportions of impure coal (coaly shale and shaley coal), carbonaceous shale and partings reduce the net coal thickness significantly. Coal lithoypes are variable, with banded coal predominant in the Barro Branco seam, and banded dull and dull coal predominantly in Bonito and Irapuá seams, respectively. Results from petrographic analyses indicate a vitrinite reflectance range from 0.76 to 1.63 %Rrandom (HVB A to LVB coal). Maceral group distribution varies significantly, with the Barro Branco seam having the highest vitrinite content (mean 67.5 vol%), whereas the Irapuá seam has the highest inertinite content (33.8 vol%). Liptinite mean values range from 7.8 vol% (Barro Branco seam) to 22.5 vol% (Irapuá seam). Results from proximate analyses indicate for the three seams high ash yields (50.2 – 64.2 wt.%). Considering the International Classification of in-Seam Coals, all samples are in fact classified as carbonaceous rocks (> 50 wt.% ash). Sulfur contents range from 3.4 to 7.7 wt.%, of which the major part occurs as pyritic sulfur. Results of X-ray diffraction indicate the predominance of quartz and kaolinite (also pyrite). Gypsum, gibbsite, jarosite and calcite were also identified in some samples. Feldspar was noted but is rare. The major element distribution in the three seams (coal basis) is dominated by SiO 2 (31.3 wt.%, mean value), Al 2 O 3 (14.5 wt.%, mean value) and Fe 2 O 3 (6.9 wt.%, mean value). Considering the concentrations of trace elements that are of potential environmental hazards the Barro Branco, Bonito and Irapuá seams (coal base) are significantly enriched in Co (15.7 ppm), Cr (54.5 ppm), Li (59.3 ppm), Mn (150.4 ppm), Pb (58.0 ppm) and V (99.6 ppm), when compared to average trace elements contents reported for U. S. coals. Hierarchical cluster analysis identified, based on similarity levels, three groups of major elements and seven groups of trace elements. Applying discriminant analyses using trace and major element distribution, it could be demonstrated that the three seams from Santa Catarina show distinct populations in the discriminant analyses plots, and also differ from the coals of Rio Grande do Sul analyzed in a previous study. © 2010 Elsevier B.V. All rights reserved. 1. Introduction In Brazil, economically important coal deposits occur in the southern part of the Paraná Basin (Fig. 1A), where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina (Informativo Anual da Indústria Carbonífera, 2000). The study area is part of a tectonic unit in southwestern Gondwana known as the Paraná Basin (Milani et al., 1994), a large intracratonic basin located in the central-eastern part of the South American Platform (Fig. 1A). The sedimentary fill of the basin has been divided by Milani et al. (1994) into six second-order depositional sequences (Ordovician–Silurian to Late Cretaceous), with the coal-bearing strata International Journal of Coal Geology 84 (2010) 213–236 ⁎ Corresponding author. Tel./fax: + 55 51 3308 6355. E-mail address: Wolfgang.Kalkreuth@ufrgs.br (W. Kalkreuth). 0166-5162/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.coal.2010.08.008 Contents lists available at ScienceDirect International Journal of Coal Geology journal homepage: www.elsevier.com/locate/ijcoalgeo