Meso and microscopic characterization of deformation bands in porous sandstones: an example on the Paleozoic, Pre- and Sin-rift sequences of the Araripe Basin, Northeast of Brazil

Abstract

Deformation bands are narrow tabular volumes developed in porous sandstones. Although these structures are a product ofbrittle deformation, they may have internally a continuous displacement gradient. When granular cataclasis is the dominantdeformation mechanism, the initial properties of their host rocks (i.e., porosity and permeability) can change significantly.The deformation bands in sandstones from the pre- and syn-rift of the Araripe Basin were studied in meso and microscalein order to classify them and to understand the deformation mechanisms involved during their nucleation and development.Their geometric-spatial, kinematic, and rheological criteria allowed establishing relations between the origin of deformationbands and lithification of their host rocks. Additionally, some inferences on their influence to the fluid flow in thereservoir-scale were outlined. Moreover, the study of deformation bands contributed to the understanding of the tectonicevolution of the studied basin. Accordingly, the study of deformation bands can support research on local and regionalaspects of the tectonosedimentary evolution of sedimentary basins.

Keywords

• Deformation bands
• Araripe Basin
• Granular cataclasis