Marinos was an internationally-renowned engineering geology lecturer, researcher, independent consulting engineer, and past president of The International Association of Engineering Geology.

Having received a degree in mining engineering from the School of Mines of the National Technical University of Athens in 1966, Marinos progressed to a postgraduate degree in applied geology, followed by a PhD in engineering geology from the University of Grenoble, France in 1969.

Up till 1977, he worked for French and Greek design and construction companies, subsequently receiving a professorship at the Democritus University of Thrace, northern Greece.

Marinos was Professor of Engineering Geology at the National Technical University of Athens for many years, and served as head of the geotechnical department. He was also director of the graduate course in tunnelling and underground construction from 2001-2004 and 2006-2008.

As well as being a visiting professor to the geology departments of several European universities, he wrote numerous technical papers, particularly with Hoek on predicting tunnel squeezing problems in weak heterogeneous rock masses; he later undertook work on anisotropic flysch. In 2013, he was awarded the Chevalier de l’Ordre des Palmes Académiques by the French government.