The connemara eastern boundary fault: A review and assessment using new evidence

The boundary between the Carboniferous sedimentary rocks and the igneous and metamorphic rocks of the Connemarabasement between Galway andOughterard has been described, either all or in part, as an unconformity or a fault known as theOughterard Fault.We present newdata on the geology of this boundary. A significant faulted contact in theMoycullen area is described for the first time and integratedwith other newand existing data to forma reassessment of the nature of the boundary. Arguments for the presence of a fault or unconformity are posited. It is concluded that the whole length of the boundary is faulted. Finally, an exploration of possible extensions to the boundary fault is presented. It is suggested that the fault zone could extend southwards into the Gort Lowlands, and, at the northern end, it may be linked to the Maam Valley Faults.