Dirtlow Rake openworks, near Castleton, Derbyshire

Originally uploaded for the GuesswhereUK Group.

This is part of Dirtlow Rake lead vein 'openworks' where the vein has been excavated from the surface leaving a slot with walls of limestone on each side. In this particular location the vein splits into a complex of several branching and rejoining sub-parallel veins formed along a strike-slip duplex fault structure. Most of the movement along the faults was near-horizontal as evidenced by horizontal slickensides (groove marks) along the vein walls.

This part of the vein has been worked since medieval times. In the floor of the opencut are numerous old shafts which accessed the deeper parts of the vein mostly from the 16th and 17th century onwards.