Horst Marschall studied mineralogy at the University of Heidelberg, where he subsequently received his doctorate (receiving the university's Ruprecht Karls Prize for the dissertation). From 2005 to 2010 he conducted research at the University of Bristol, the first two years of which were spent as a Marie Curie Research Fellow. From 2011 he worked at the Woods Hole Oceanographic Institution in Massachusetts, USA. Since 2016, he has been the Wilhelm Heraeus Endowed Professor of Deep Earth Processes at the Goethe University Frankfurt, Germany. In 2019, he and a colleague founded the Frankfurt Isotope & Element Research Center (FIERCE) and lead it as one of two co-directors. He is currently the director of the Institute of Geosciences at Goethe University. He also conducts research as a scientist at the American Museum of Natural History in New York City.
His research focuses on the evolution of the Earth's crust and mantle over the long period since the planet's formation and the interaction between crust and mantle. In particular, the processes that occur at the margins of the major tectonic plates, where the majority of volcanism on Earth takes place, play a central role. Marschall has already traveled to all seven continents as part of this research, including a two-month tour by tent through Antarctica. The study of the rocks is based primarily on precise mineralogical and chemical analysis, and isotope measurements are used to determine the age of formation of the rocks.
The Frankfurt Isotope & Element Research Center (FIERCE) established by Marschall is one of the leading laboratories for age determination of rocks in Europe. Marschall has published numerous scientific articles (peer-reviewed papers) in specialist journals, see the detailed list of publications on Marschall's homepage. Horst Marschall was appointed to the advisory board of the Giordano Bruno Foundation in February 2020, and he is also one of the founding advisory board members of the Hans Albert Institute.