Some paradigms in the impact-volcanic controversy that we regard as having first been established in the 1980s in fact can be traced much farther back in time, as exemplified by the heuristic neocatastrophic concepts proposed by Dmitri Sobolev and other progressive Russian scholars (Aleksey P. Pavlov, Mikhail A. Usov) of the early 20th century. They were truly conceptual forerunners of the global catastrophe model in Earth history which is now widely accepted as the volcanic/ greenhouse scenario, even if preceding thought-provoking concepts of some leading European scholars (e.g., Svante Arrhenius, Jacques J. Ėbelmen) were unknown to them.

Grzegorz Racki [racki@us.edu.pl], Department of Earth Sciences, Silesian University, ul. Będzińska 60, PL-41-200 Sosnowiec, Poland.