A refraction seismic transect from the Faroe Islands to the Hatton‐Rockall Basin

The crustal structure of the Faroe‐Rockall Plateau was studied by a 790‐km‐long refraction seismic transect consisting of two intersecting lines. The air gun shot spacing was 200 m, and the signals were recorded by 77 ocean bottom seismometers. A P wave velocity model was developed from forward and inverse modeling of the wide‐angle seismic data and incorporation of coincident multichannel reflection seismic data. Continental crust with velocities ranging from 5.6 to 6.8 km/s can be traced from the Faroe Islands, across the banks to the SW of the Faroes and into the Hatton‐Rockall Basin. The thickness of the subvolcanic crust is up to 25 km on the banks but is as little as 8 km in the channels between the banks. The thinning in the channels may be related to NW‐trending shear zones extending from major lineaments in NE Rockall Trough. Basalt layers are found along the entire transect with a total thickness of up to 4 km. Two layers with velocities of 4.9–5.2 and 5.3–5.6 km/s are thought to represent Paleogene flood basalts that can be correlated from the Faroe Islands to George Bligh Bank. Close to George Bligh Bank, an 80‐km‐wide and up to 9‐km‐thick body with velocities of 6.5 km/s is interpreted as intrusion. A 5‐km‐thick, high‐velocity lower crustal layer (7.3 km/s) extends from the area of the intrusion into the northern Hatton‐Rockall Basin. At the northern flank of Lousy Bank the transition zone to oceanic crust was encountered.