Mohorovicic discontinuity depth analysis beneath north patagonian massif

Abstract

The Mohorovicic discontinuity (Moho) is the surface that limits the Earth’s crust and mantle. It is of paramount importance in understanding and investigating the dynamics of the Earth’s interior. The GEMMA project (GOCE Exploitation for Moho Modeling and Applications), funded by the European Space Agency and Politecnico di Milano, has provided a high resolution map of the Moho surface (GEMMA Model), based on the inversion of homogeneous, well-distributed gravimetric data measured by the Steady- State Ocean Circulation Explorer (GOCE), which ensures a global coverage using gravity field. In the current paper, this Moho depth estimation (Riccardo Barzaghi, personal communication, April 20, 2012) is compared with other models based on both seismic and gravity observations, under the North Patagonian Massif (NPM). Said massif is an Argentinean plateau that stands out 500 to 700m higher in altitude than the surrounding topography and was created by a sudden uplift without noticeable internal deformation (Aragón et al. (2011b) Upper mantle geodynamic constrains beneath the north Patagonian massif, Argentina). The features described led us to analyze the crustal thickness in the area. The work describes different Moho models available in the area under study and their comparison with the GEMMA Model. The aim is to validate this well distributed, homogeneous data model in this area with sparse seismic data and check its usefulness to get more information about theMoho. According to comparisons with the different models, the crustal thickness in the study area varies between 36 and 46 km. The good agreement between the GEMMA Model and some of the other Moho models may account for the use of such model to study this little known area.