As part of the lithosphere, the crust represents Earth's rigid outer layer. Some of the tools to study the crust and its thickness are wide-angle seismic studies. To date, a series of seismic studies have been carried out in Venezuela to determine in detail the crustal thickness in the southern Caribbean, in the region of the Caribbean Mountain System in northern Venezuela, as well as along the Mérida Andes and surrounding regions. In this study, a review of the wide-angle seismic data is given, incorporating new data from the GIAME project for western Venezuela, resulting in a map of Moho depth north of the Orinoco River, which serves as the basis for future integrated models. Differences in Moho depths from seismic data and receiver function analysis are discussed. From the Caribbean plate, Moho depth increases from 20 to 25 km in the Venezuela Basin to about 35 km along the coast (except for the Falcón area where a thinning to less than 30 km is observed) and 40–45 km in Barinas - Apure and Guárico Basins, and Guayana Shield, respectively. Values of more than 50 km are observed in the Maturín Basin and in the southern part of the Mérida Andes.
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Other members of the active seismic working group of the GIAME project are Javier Sánchez-Rojas, Jorge Alcalá, Manuel Bolívar, Hugo Cerquone, Lisfer Flores, Kenny García, Christian Jímenez, Yoana Maldonado, Pedro Medina, Loveida Montilla, Henderson Pinto, Rafael Ramírez, Víctor Rocabado, María Saavedra, Colin Zelt. This paper is a contribution to the Los Andes de Mérida Integrated Geoscience project (GIAME) (FONACIT 2012002202) and the Specific Agreement PDVSA - FUNVISIS (12/09/2012). The seismic measurements were carried out with equipment from FUNVISIS and the IRIS/PASSCAL Instrument Center (Socorro, NM, USA). We thank the companies CONAGUA and GISCA for drilling the wells, CAVIM for the supply and handling of the explosives for the shooting, and the owners of the sites for the permission to carry them out. The work would not have been possible without the support of all the participants in the field, including staff and students from FUNVISIS, PDVSA-Intevep, PDVSA-E&P, UCV, ULA, USB, ABAE, FII, Protección Civil, to whom we are highly grateful. The GMT software package (Smith and Wessel, 1990; Wessel and Smith, 1991; Wessel et al. 2019) was used to generate the maps. We thank F. Niu for providing the grid of the Moho depth map from receiver function analysis (Fig. 26), and two anonymous reviewers for their constructive observations, which contributed to improving the manuscript considerably.
© 2020 Elsevier Ltd
- Crustal thickness
- Geological provinces
- Wide-angle seismic