Petrology, Geochemistry, And Tectonic Significance Of Crosscutting Dikes In Nahant, MA

Abstract

During the late Proterozoic the Avalon Terrane rifted away from the Gondwana supercontinent. As the terrane was moving towards the modified margin of Laurentia, around 488 Ma the Nahant Gabbro intruded. This was later intruded by a series of dikes in the late Devonian. Drone imagery and field survey was used to map multiple sets of cross cutting dikes outcropping along the Castle Rock shoreline in Nahant, MA. In a key area we see five cross cutting dikes. These intersecting dikes are analyzed for their petrology and geochemistry in an attempt to identify different magmatic events.