Application of Marine Magnetic and Gravity Data in Mapping Basement and Sedimentary Horizons in the Rovuma Basin, Mozambique.

Abstract

Marine magnetic and gravity data, acquired in 2010 during seismic data acquisition over part of the Rovuma Basin, Mozambique, was used to map basement and two intra-sedimentary horizons. Depth estimates to these three horizons were derived from the interpretation of energy density spectra of magnetic and gravity data. Magnetic lineaments often corresponding to fault patterns were interpreted from magnetic data using the ACM (Automatic Curve Matching) method, which is based on the improved Naudy technique (Shi, 1999). The new spectral technique named Multi-Window-Test (MWT) was used in this project to detect magnetic susceptibility and density contrasts within the sediments at stations located on a regular mesh which covers the whole project area. The lateral correlation between stations allowed the identification of multiple horizons. The results derived from potential field data show a good correlation with seismic and well intersections. The Energy Spectral Analysis method was applied successfully in the Rovuma Basin and the new MWT technique was found to be a valuable tool in mapping the sedimentary horizons from the potential field data.