Authors: Patricia de Lugão (presenter), Eric Corrêa, Berthold Kriegshäuser, Strataimage Consultoria Ltda; Dallas Sherman, Frontier Geosciences Inc; Steve Constable, Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego
The objective of this study was to characterize the background geology and electrical conductivity structure of the Punta Del Este Basin prior to continued exploration using the marine magnetotelluric (MMT) method. Data were collected at 165 sites along five profiles, with one 233 km-long line co-located with a low frequency seismic line and extending onto what should be oceanic crust in deep water (Constable and Sherman, 2014). The continental margin of Uruguay is segmented by the Río de la Plata Transfer System (RPTS) (Soto et al., 2011) with a NW–SE trend that interrupts and sinistrally displaces several geological and geophysical features, such as the seaward-dipping reflectors (SDRs) wedges, which are absent in the central sector of the Uruguayan offshore. The RPTS is limited by the Polonio High at north and was an important crustal structure during the Late Jurassic rifting and opening of the South Atlantic (Morales et al., 2017).The MMT data were inverted to produce two-dimensional (2D) resistivity models at depth that were interpolated into a 3D resistivity model revealing the structure of the RPTS. By analyzing the main features of the 3D model, three geoelectric limits were defined: top of rift at 30 Ohm.m, top of basement at 100 Ohm.m and crustal structures at 300 Ohm.m. At the basement level, the RPTS shows a NW-SE channel, marking two depocenters: at North, a deeper, NW-SE structure showing a sub-structure with NE-SW direction. At South, a channel with a clear NW-SE main trend. The crustal structures present three blocks and show the RPTS segmented at two zones of weakness with a clear relationship with the depocenters. Also, at the north side, block 3 is segmented by a NE-SW structure at the same level of the main weakness zones.
Patricia de Lugão, Strataimage Consultoria Ltda
Patricia holds a PhD in Geophysics from the University of Utah.
She has 29 years of experience in the industry, and currently is Senior Geophysicist and Managing Partner at Strataimage Consultoria Ltda, Rio de Janeiro, Brazil, where is responsible for managing all aspects of geophysical projects. Previously, she worked in companies as Western Geophysical, Landmark and Schlumberger.
Patricia is a member of SEG and EAGE.