Hydrothermal Sr exchange at the contact of the Dumbarton Rock basalt

Abstract
Synopsis: The margin of the Dumbarton Rock basalt was contaminated by sedimentary Sr with a high 87 Sr/ 86 Sr ratio. This was probably introduced by hydrothermal fluids in a process of fluid–rock Sr exchange. Fluids followed a preferred path just inside the contact where permeability was increased by cooling joints.