Integration of High Resolution Falcon TM Gravity Gradiometry and Seismic data: an example from Northern Argentina

Newly acquired airborne gravity gradient and magnetic data were used to model the tectonic framework and basement configuration beneath the Chirete concession area, onshore, northern Argentina, using the existing seismic data as constraints. The study area is comprised of approximately 3675 square km and covers approximately 35 km in an east-west direction and 105 km in north-south direction. The main project goal was to modeling the basement and associated major structural elements for selection of oil & gas prospects. The basement related faults/lineament maps were generated using several enhancements of gravity gradient and magnetic data. 2D seismic depth sections were used as initial constraints for 2.5D and 3D gravity and magnetic modeling. Well log densities and velocities are also constrained in this modeling process. The basement depth estimates are computed from the total magnetic intensity profile data. The Werner, Euler, and Peters half slope techniques are used in basement depth computations as well as the depths to the magnetic sources within the sedimentary section. This interpretation was then refined by utilizing the gravity gradient data and seismic data using 2.5 D and 3D modeling. Several of these depths are related to volcanic<br>sources and were identified as igneous provinces and probably related to the rift and post rift periods. The basement depths show significant variation from south to north and ranging approximately 4-13.5 km below sea level. The enhanced potential field data yielded basement faults and structural framework of the area. The general basement faults trends are striking mostly in ENE-WSW direction. Two major East-West faults were identified as being the major bounding faults of the Lomas de Olmedo rift. There exists a remarkable correlation between these faults derived independently from seismic reflection data and enhanced Airborne Gravity Gradiometry data. A number of positive structural features were identified with the associated faulting and may provide new prospects for well drilling.