Seismic studies in the North Celtic Sea Basin: implications for basin development

Modelling of seismic refraction data from the North Celtic Sea Basin offshore Ireland demonstrates the presence of a NNW-trending basement flexure. Mesozoic sediments are 4 km thick on the west and 6 km thick on the east of the feature, which is Interpreted as a transfer fault zone lying along a major reactivated basement fracture. Bulk extension is greater in the lower lithosphere than in the upper crust, with the interface being a rheologically regulated mid-crustal detachment surface. The basin developed in response to the interplay between periodic disengagement along the detachment and selective strain transfer into the upper crust.