Integrated interpretation of geophysical anomalies in the western Ross Sea (Antarctica)

In the present paper, a seismic and magnetic profile recorded in the Western Ross Sea, near Coulman Island, is analyzed. The seismic line is characterized by some buried structures whose origin is not fully understood. Automatic bidimensional velocity analysis and tomographic inversion, as well as inversion of the magnetic data over the examined profile were performed. Analysis of the velocity field identified a local inhomogeneity whose depth is comparable to that of the seismic structure. The quantitative analysis of the magnetic data, on the other hand, supports the presence of magmatic bodies whose depths and shapes ere in fairly good agreement with the structure and the velocity inhomogeneity. We concluded that the observed structures are due to magmatic intrusions (sills and dikes) which caused the deformation of the upper sedimentary sequences and the consequent anticlinal structure, successively remodeled by the erosional action of the Antarctic glaciers.