now at: CERENA – Centro de Recursos Naturais e Ambiente Instituto Superior Técnico (Universidade de Lisboa), Av. Rovisco Pais Lisboa 1049-001, Portugal
Engenharia Geológica, Centro de Engenharia, UFPel Praça Domingos Rodrigues 02, Bairro Porto, Pelotas-RS, Brazil
PUC-RS, Porto Alegre-RS, Brazil
P. A. R. Reginato
IPH, UFRGS, Porto Alegre-RS, Brazil
R. B. Acauan
FEPAM, Porto Alegre-RS, Brazil
V. A. de Amorim
Geologist, Professional Services, Brazil
M. Z. Remde
Engineering Geologist, Professional Services, Brazil
Abstract. This paper examines the domes and basins, regional arcs and synclines, and brittle structures of the Paraná Basin flood volcanism to characterize the deformational phases in its Jurassic to Cretaceous history. First-stage fieldwork revealed brittle structures, extensional joints, and strike-slip faults, and second-stage fieldwork investigated the connections of the brittle structures to both open folds and dome-and-basin features. Fault-slip data inversion was performed using two different techniques to distinguish local and remote stress/strain. Geometric and kinematic analyses completed the investigations of the deformation, which characterized two deformational phases for the Jurassic to Cretaceous periods in the Paraná Basin. Both developed under regional bi-directional constrictional (σ1 ≥ σ2 ≫ σ3) stress regimes that produced a number of non-cylindrical folds. A D1 deformational phase produced the N–S and E–W orthogonally oriented domes and basins. The D2 arcs and synclines are oriented towards the NW and NE and indicate a clockwise rotation (35–40°) of both horizontal principal stress tensors. The extensional joints and strike-slip faults characterize the local stress field in the outer rim of the orthogonally buckled single volcanic flow, whereas the inner rim of the buckled single flow supported constriction and thus, developed the local arcuate folds.
This preprint has been withdrawn.
How to cite. Strieder, A. J., Heemann, R., Reginato, P. A. R., Acauan, R. B., de Amorim, V. A., and Remde, M. Z.: Jurassic–cretaceous deformational phases in the Paraná intracratonic basin, southern Brazil, Solid Earth Discuss., 7, 1263–1314, https://doi.org/10.5194/sed-7-1263-2015, 2015.
Received: 11 Mar 2015 – Discussion started: 02 Apr 2015
Palaeostress inversion methods were applied to fault-slip data from the Paraná Basin. Geometric and kinematic analyses identified two deformational phases for the Jurassic and Cretaceous periods. Both these phases were developed under bi-directional constrictional stress. Local and regional structural features are distinguished, enabling to construct a new structural scenario in tectonic evolution of the Paraná Basin during the Jurassic to Cretaceous periods, including the Gondwana breakup.
Palaeostress inversion methods were applied to fault-slip data from the Paraná Basin. Geometric...