Cecilio Quesada's professional career was based at Instituto Geológico Minero de España (Spanish Geological Survey), until he retired from there in 2013. He is currently an Honorary Professor at the Faculty of Geological Sciences, Universidad Complutense, Madrid, where he also served temporarily as an Associate Professor. As a "survey person", his research interests, past and present, include geological mapping, regional geology, tectonics and geochronology, mainly focused on the Variscan orogen in its global context. He has participated in ten IGCP projects since 1979, and is currently involved in Project 648: Supercontinent cycles & Global Geodynamics.

José Tomás Oliveira holds a Ph.D. and Agregação (Portuguese postdoctoral degree). He is a geologist and is currently collaborating at Laboratorio Nacional de Energia e Geologia, former Geological Survey of Portugal, where he acted also as Head of the Geology and Mineral Resources departments. As a survey geologist,his main activities have focused on regional geological mapping in Portugal and Mozambique, with a particular interest in stratigraphy, clastic sedimentology and basin analysis. He has been an Invited Professor at universities in Portugal and Angola, author and editor of several geological maps, and was co-editor of the recently published Geological Map of Portugal and Spain, 2015, scale 1:1,000,000.