Interpretation Of The Upper Crust From Potential Methods In The Region Of Payenia And Malargüe Fold And Trhust Belt

Abstract:

ABSTRACT: INTERPRETATION OF THE UPPER CRUST FROM POTENTIAL METHODS IN THE REGION OF PAYENIA AND MALARGÜE FOLD AND TRHUST BELT

Application of potential methods to hydrocarbon exploration in the Mendocina main mountain range, Neuquina Basin. Different geophysical techniques, such as the potential methods, were applied to characterize the Andean depocenters in the northwestern border of the Neuquen basin, in the geologic province of Payenia. These techniques allowed studying the structures at the crust level to conduct hydrocarbon exploration. Gravimetric and magnetometric measures were carried out supported using GDPS (700 stations) and more than 1000 gravity values were obtained and checked, which were provided from several campaigns in the last three decades and constitute the database of the Geophysics and Seismological Institute “Volponi”. Also, digital data from aeromagnetic reports by SEGEMAR (ServicioGeológicoMineroArgentino) were provided by YPF S.A. Gravimetric and magnetometric maps were drawn to study the upper crust sources. 2D and 3D inversion gravimetric models were prepared, emphasizing the resolution of structures placed in this area and integrating geologic and geophysics information. The 3D model of crystalline basement based on the average density values from a local well played a key role in identifying the high and low structures already studied by other authors, but also a sub basin not reported up to now. The detailed profile gives information about the 2D depocenter structure, showing a deepening and filling which wedges into a raised basement block belonging to San Rafael block. The thickness of the volcanic-clastic cover shows a first time reported maximum of 4000 meters deep.

Keywords: sediment thickness, hydrocarbon exploration, 2D and 3D inversion gravimetric models.