A comparison of the age and composition of the Shelburne dyke, Nova Scotia, and the Messejana dyke, Spain
New 40Ar/39Ar age determinations on biotite from the Shelburne dyke of Nova Scotia and from the Messejana dyke of Spain are identical at 203 ± 2 Ma. In addition, both dykes have similar chemical compositions and probably represent similar magma sources, petrogenetic processes, and tectonic settings related to an early phase of opening of the North Atlantic Ocean.