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.

You do not currently have access to this article.