In short, the Miocene basalt-rocks of Iceland present precisely the same features as the similar rock-masses of the Færöes. Like the latter they probably formed at one time a wide elevated table ...

As it cools and hardens, it forms extrusive igneous rock. In theory ... just as we did with geothermal energy 200 years earlier in Iceland,” Pálmadóttir said in a statement sent to IFLScience.

Sedimentary and extrusive igneous rocks are originally laid down in horizontal layers and any change from that is viewed as a disturbance of those layers (something happened later) - folding, tilting ...