“…Sustained investigations, however, did not really get underway until the seminal work of Émile Thellier in France (Thellier, 1936), and its somewhat later counterpart in Britain (Cook and Belshé, 1958;Aitken and Weaver, 1962). Since then, a substantial body of data has been built up from several European countries including Austria (Schnepp and Lanos, 2006), Belgium (Hus and Geeraerts, 1998;Spassov et al, 2008), Britain (Zananiri et al, 2007), Bulgaria (Kovacheva et al, 2014), Denmark (Abrahamsen, 1996), France (Thellier, 1981;Bucur, 1994), Germany (Schnepp and Lanos, 2005), Greece (Evans, 2006;De Marco et al, 2014), Hungary (Márton, 2003), and Italy (Evans and Hoye, 2005;Tema et al, 2006). For Spain, a few preliminary data appeared sporadically, but the first systematic compilation was published by Gómez-Paccard et al (2006a).…”