Gravity Gradient Tensor of Vargeao Impact Structure, South Brazil

The gravity gradiometry allows to study the density variation of bodies in three directions. This geophysical method represents the shorter wavelengths with higher resolution being more sensitive to small variations. In this work, we present the gravity gradient tensor of the well-preserved complex impact structure Vargeăo formed on basaltic flows of the Serra Geral Formation (133-131 Ma) of the Paraná Basin. The gravity gradient tensor components were calculated using only the observed gravity data. The method is based on the solution of the Laplace equation and the Fourier transform of the original data, requiring few algebraic manipulations in the frequency domain. We demonstrate that this technique contributes significantly to the interpretation of complex structures such as Vargeăo. The analysis of the results allow to determine the correct location (spatial position and limits edge) of the subsurface bodies and to estimate its center of mass. We show that this impact structure is less symmetrical on east-west direction. Moreover, our results can contribute to a better understanding of the impact crater formation which is important for understanding the planetary evolution of the Solar System.