The Cromerian Complex in Europe is currently subdivided into 3 glacial periods and 4 interglacial periods , which are equivalent to Marine Isotope stages 13 to 21 .
The Cromerian Complex in Europe is subdivided into 3 glacial periods and 4 interglacial periods . 
 Both the Cromerian Stage and Complex are equivalent to Marine Isotope stages 13 to 21 .