The structural framework of the Araripe Sedimentary Basin, Borborema Province, based on aeromagnetic data

Abstract

This paper aims an updated interpretation of the Araripe Sedimentary Basin internal structure, located in the south portion of the Borborema Province, Brazilian northeast, through aeromagnetic data interpretation, provided by the Geological Service of Brazil. This basin is recognized as a set of asymmetrical half-grabens fragmented by basement highs, complex faults system and E-W to NE-SW lineaments, those associated with the Borborema Orogen trend, and NW-SE lineaments, related to extensional processes whose evolution could be associated to the Reconcavo Basin aborted-rift system. From the geophysical map of total magnetic intensity, the first order derivatives were extracted the in the x, y, z directions; and the total horizontal derivative, the analytic signal amplitude (ASA) and the titl derivative were obtained. The Euler deconvolution was applied to the ASA grid, allowing an estimation of the depth and horizontal position of the top of the main anomalous magnetic sources. The joint analysis of the various maps made possible the interpretation of magnetic domains and lineaments, which were associated with the main subsurface geological structures that make up the structural framework of the basin. The structural pattern of the basin shows remarkable lateral variation, from W to E, as shown by the division of the magnetic domains, indicating substantial variations in the thickness of the sedimentary rocks above the basement.