Czech Conroy
One of Eigg's dykes
Repeated eruption of fluid basaltic lavas built up layers several hundred meters thick. Accompanying stresses and stretches produced numerous dykes like this one, which is pointing to the isle of Rum. According to ‘The Geology of Eigg’, the term 'dyke' originates from instances where vertical basalt dykes have been intruded into soft sediments or lavas, and erosion leaves them standing proud. However, at Laig Bay, where this photo was taken, the reverse is the case: the most resistant rocks are the baked sandstones of the dyke margins; the sandstones away from the dykes are of intermediate resistance, and the most eroded rocks are the basalt dykes themselves.
One of Eigg's dykes
Repeated eruption of fluid basaltic lavas built up layers several hundred meters thick. Accompanying stresses and stretches produced numerous dykes like this one, which is pointing to the isle of Rum. According to ‘The Geology of Eigg’, the term 'dyke' originates from instances where vertical basalt dykes have been intruded into soft sediments or lavas, and erosion leaves them standing proud. However, at Laig Bay, where this photo was taken, the reverse is the case: the most resistant rocks are the baked sandstones of the dyke margins; the sandstones away from the dykes are of intermediate resistance, and the most eroded rocks are the basalt dykes themselves.