The basement geology of the Porcupine High – new geochronological constraints from the westernmost Caledonides

Key Points

• This research aims to understand the geochronological features of the Porcupine High and its geological connections to surrounding regions.
• Geochronological analysis of granitic and metasedimentary rock samples from the Porcupine High.
• Utilization of geophysical techniques to trace the Fair Head–Clew Bay Line.
• Examination of Acadian overprint in igneous and metasedimentary rocks.
• Identified granitic basement aged 1.3 Ga with high-temperature Grenville metamorphism.
• Documented very low-grade Caledonian metamorphism in the Lower Dalradian metasedimentary cover.
• Traced Fair Head–Clew Bay Line with strong Acadian overprint (425–415 Ma) on rocks from 500–481 Ma.