Shale dykes in Carboniferous delta sequence
Avatar

Shale dykes in Carboniferous delta sequence

by David Tanner, Leibniz Institute for Applied Geophysics (LIAG), Hannover, Germany

These shale dykes or "ball and pillow" structures are exposed in the Carboniferous deltaic sequences in County Clare, Ireland. They are evidence of overpressuring of the shales by the sand bodies above them. Compass is 15cm long.